Dark Chocolate Reduces Blood Pressure and Improves Insulin Sensitivity in Just Two Weeks

Not all things that are good for you taste bad. (Photo by CC Chapman)

Everyone knows that dark chocolate is healthy, but how many of us really know why exactly it's healthy? It's the same as with red wine: it's common knowledge that it's healthy – it contains those magical polyphenols, after all – but the actual effects are mentioned less frequently.

Most things that are labeled healthy by mainstream media are things that reduce the risk of cardiovascular disease. The same is true of red wine and dark chocolate, although I'm sure there's more to them than just heart health. Resveratrol, found in red wine, for example has a multitude of effects. What I found interesting, however, is how quickly dark chocolate can have a beneficial effect on two common health problems: blood pressure and glucose intolerance (link).

Study design

To study how dark chocolate affects glucose tolerance, insulin sensitivity and blood pressure, 19 subjects with hypertension and impaired glucose tolerance were chosen for the experiment. Smokers and those with significant overweight (BMI > 30) or diabetes were excluded.

The subjects were then randomized and given either 100 grams of flavonol-rich dark chocolate or flavonol-free white chocolate for 15 days. They were told to eat the chocolate in two 50 gram doses, one for breakfast and one for lunch. After a washout period of one week the two treatments were switched, so that those who had been eating dark chocolate got white chocolate instead and vice versa.

Results

Two weeks of dark chocolate consumption decreased insulin resistance significantly compared to baseline and white chocolate. The graphs below show the results from various measurements.

The graph on the left show the results from the homeostasis model asssessment of insulin resistance (HOMA-IR) for baseline, flavonoid-rich dark chocolate (FRDC) and flavonoid-free white chocolate (FFWC). The three other graphs show the differences in insulin sensitivity. White chocolate had no effect on any of the tests, while dark chocolate improved glucose and insulin responses to the oral glucose tolerance test.

Compared to baseline, blood pressure decreased after dark chocolate consumption. White chocolate had no effect on 24-h, daytime or nighttime blood pressure. The graphs below show the changes in systolic and diastolic blood pressure.

Dark chocolate also increased flow-mediated dilation, which measures endothelial function. Again, white chocolate had no effect compared to baseline. Interestingly, dark chocolate also reduced LDL cholesterol compared to baseline and white chocolate but had no effect on triglycerides and HDL.

Conclusion

In people with hypertension and impaired insulin sensitivity, dark chocolate (but not white chocolate) reduced blood pressure and improved glucose tolerance and insulin sensitivity. Endothelial function was also improved.

What's interesting about this study is that the duration was so short: the participants saw improvements in just two weeks. And, unlike in many studies, they weren't given cocoa powder or a small dose of dark chocolate, but an entire 100 gram chocolate bar for each day. Also, the subjects were not diabetic, and they only had stage 1 hypertension (systolic 140-159 mmHg, diastolic 90-99 mmHg), which suggests that dark chocolate is helpful even before things get really bad.

I try to keep my intake at around 50 grams per day on average, but at least this study shows that higher amounts are not bad for cholesterol, blood pressure or insulin sensitivity. The reasons I try to stay below 100 grams are the high iron and copper contents and possible lead contamination in cocoa powder.

Still, if you're eating milk chocolate with a low cocoa content (typically around 30%), consider upping the ante and slowly progressing towards darker chocolates. It's the better choice in at least five different ways.

For more information on blood pressure, insulin and cholesterol, see these posts:

Hibiscus Tea Increases HDL, Lowers LDL and Triglycerides
The Many Health Benefits of Rooibos Tea
Intermittent Fasting Improves Insulin Sensitivity Even without Weight Loss
Intermittent Fasting with a Condensed Eating Window – Part III: Fasting Blood Glucose, Cortisol & Conclusion

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Hibiscus Tea Increases HDL, Lowers LDL and Triglycerides

 

Hibiscus tea is often served cold with sugar. (Photo by molossoidea)

When it comes to health benefits and drinks, green tea gets most of the publicity. And with good reason – from what we know, it seems to have the widest range of positive effects out of all beverages. But that's not to say that there aren't other less known drinks out there that have health benefits of their own.

One such beverage is hibiscus tea, a herbal infusion made from the calyces of the Hibiscus sabdariffa flower. Hibiscus is also known as sorrel, roselle, karkadé and flor de Jamaica, depending on the region. Earlier this year, I wrote about two studies showing that hibiscus tea reduces blood pressure. In the second study, hibiscus tea was compared with black tea, and guess what – hibiscus tea wone hands down.

In fact, the group that drank black tea saw an increase in blood pressure. That was black tea – as far as I know, there have been no direct comparisons between green tea and hibiscus tea, but even green tea's effects on blood pressure seem to be small or nonexistent. So green and black tea, while very healthy, may not be enough if you want to cover all bases.

I wrote in the earlier posts that to my knowledge, there had been no studies on hibiscus tea and cholesterol, even though the drink is traditionally used to lower cholesterol. Today, however, I found a paper that shows hibiscus tea is good for cholesterol too (link). Granted, the paper appeared in the Journal of alternative and complementary medicine, which has published some papers that seem to be of questionable quality, but this one seems pretty legit.

For the experiment, 60 patients with type II diabetes were randomly assigned into two groups. One group got black tea and the other got hibiscus tea (which the authors refer to as "sour tea"). The participants were told to drink one glass (1 tea bag in boiling water, steeped for 20-30 minutes) twice a day for a month.

The subjects that drank black tea did not show improvement in any of the parameters measured. None of the changes in total cholesterol, LDL, HDL, triglycerides and lipoprotein (a) were statistically signifcant.

Those who drank hibiscus tea, on the other hand, saw several improvements in their cholesterol levels. Total cholesterol went from 236.2 to 218.6 mg/dL. HDL increased from 48.2 to 56.1 mg/dL, while LDL decreased from 137.5 to 128 mg/dL. Triglycerides went down rather dramatically, from 246.1 to 209.2 mg/dL. Lipoprotein (a) was unchanged.

The authors also reference several other papers showing similar results in humans and animals. For example, one study showed a reduction in cholesterol levels in healthy men and women taking a hibiscus extract (link). This would suggest that the beneficial effects of hibiscus are not only limited to diabetic patients.

I'm not sure why I didn't find these papers the last time I did a pubmed search, but I'm glad I came across them now. I guess it's time to put hibiscus tea back on the menu, next to green tea and rooibos tea.

My favourite way to drink it is to make a big glass of hibiscus tea the normal way, then after 15 minutes of steeping pour the tea through a sieve into a larger container, add twice as much cold water and put it in the fridge. It's ready to drink in about an hour. It's especially good in the summer, best enjoyed with ice and a little sugar for taste.

For more information on tea, cholesterol and health, see these posts:

The Many Health Benefits of Rooibos Tea
Black Tea Is More Effective in Activating Superoxide Dismutase (SOD) than Green Tea
Refined vs Red Palm Oil and Cholesterol
Anthocyanins from Berries Increase HDL and Lower LDL

Read More......

My Current Health Regimen v2.0

One of the changes has been an increased intake of fruit and vegetables. (Photo by YimHafiz)

This is my updated health regimen, aimed at adding a significant number of healthy years to my expected lifespan. As it's subject to change, I will keep this post updated accordingly. Major revisions (such as v2.0) will appear once a year or so; minor changes (such as v2.1) will be made as needed. With every major revision, I will move the post from the archives to the front page.

Since a long, healthy life is preferable to a short life by most people, following the regimen would make sense even without considering technological innovations. The true goal of my regimen, however, is to stay alive long enough to see rejuvenation therapies become a reality. In the long run, each year that I'm able to add to my expected lifespan now through things like dietary changes, exercise, and supplements, may grant me several extra years in the future.

Therefore, even those lifestyle changes that require considerable effort and resources while offering a seemingly limited benefit, make sense if one looks at the big picture. For a chance to see the world in 2090, I'm willing to skip the cheeseburger today.

My health regimen consists of four categories: diet, supplements, physical exercise, and brain health. All of the items under each category have some kind of scientific basis, and in contrast to my ongoing experiments, will remain a part of the regimen for the time being. Therefore, my current experiments are not a part of my long-term health regimen – unless they prove to be beneficial, in which case they'll be moved from ongoing experiments to the regimen.

Main changes from v1.0: none.

Avoiding harmful foods

The most important part of my diet is avoiding unhealthy things; increasing the intake of healthy things only comes in second. This is because preventing damage from happening in the first place is easier than repairing it later on.

I consider the worst culprit of modern diets to be an emphasis on grain products, fructose, and polyunsaturated fatty acids. There's considerable evidence to suggest that most people would do much better without them. Hence, things like pasta, rice, bread, candy, fruit juices, and most vegetable oils are off the daily menu. I only eat them rarely, and then simply because they taste good. For the past few months, I've allowed myself to eat whatever I want once a week (usually foods like pizza or fresh bread), which seems to be working well.

I originally cut back on my fruit intake, which used to be quite high some years ago, because I learned that fructose increases triglycerides especially in men, and fructose is not handled very well by the body in general. I later learned that fructose also forms AGEs much more rapidly than glucose, which kept me from reintroducing most fruits to my diet and eat berries instead, since they contain more nutrients per fructose calorie. However, I've now increased even my fruit intake a little, having read more about the AGE-inhibiting effects of phytonutrients found in fruit. I will expand on this later, but for an example of what I'm talking about, see my post about carotenoids inhibiting lipid peroxidation.

While much of this fits well with paleo dieting, I also diverge from the paleo diet these days. You may or may not remember that I used to be a potato hater back in the day, both because they could not be eaten raw (making them anti-paleolithic) and because of their high carb content. Basically, potatoes are just empty calories. But once you have your insulin sensitivity and blood glucose under control, I don't think a few potatoes now and then is much of a concern. At least they're low in fructose.

As you may recall, I followed a low-carb diet for the past year with an emphasis on paleo foods. I got on the low-carb, high-fat wagon in the first place to prove that eating a diet high in fat does not make you fat – and it didn't. However, this diet combined with my year-long intermittent fasting experiment resulted in a moderate-to-high intake of protein, the longevity effect of which I'm now questioning. To lower my protein intake slightly means eating either more fat or more carbohydrates, and since my fat intake is already very high, I've reintroduced some carbs into my diet. That is, I now occasionally eat potatoes not because I think they are necessary for health, but because they are low in protein. More on protein and longevity in future posts.

I still don't make nuts a dietary staple, because of their poor omega-3/omega-6 ratio and because I like to keep my PUFA intake low. That is, I aim not only for a good ratio of omega-3 and omega-6 fatty acids, I try not to eat too much of them in general. Omega-3 is particularly prone to undergo lipid peroxidation, and while nuts probably have micronutrients that protect them from oxidation to some degree, I'm playing it safe until I learn more.

Main changes from v1.0: slightly increased carb intake, slightly decreased protein intake, slightly decreased polyunsaturated fatty acid intake.

Eating healthy foods

Despite eating some more carbs these days, my diet is still fairly low in carbohydrates. My daily intake used to be around 100 grams; I have not measured my current intake, but I suspect it's around 100-150 grams these days. My main protein sources used to be meat, fish and eggs, but during the past year I've cut back on eating eggs because of their high methionine content. I'm still figuring out whether methionine restriction makes sense in humans, but in the meantime I limit my egg intake to 3-4 eggs a week.

Sources of fat, in the order of importance, are olive oil, palm oil, butter, cocoa butter, coconut milk, ghee, coconut oil, and sesame oil. Olive oil tops the list because I love the taste and because it's high in MUFAs but low in PUFAs and consistently does well in just about every health study. There may not be anything magical about MUFAs per se, but even if it's the polyphenols in olive oil that are behind all the positive health effects, olive oil still seems like a good choice. Palm oil is there because it's rich in tocotrienols (at least compared to other natural foods), low in PUFAs and high in SAs (making it suitable for heating), and because I've grown to like the taste.

Lard is off the menu for now because I ran out. Heavy cream has been replaced by coconut milk, partly because of dairy products increasing IGF-1, which may be bad for longevity (more on that in future posts). I don't eat cocoa butter raw (although I could, it's delicious), but I get plenty from all the dark chocolate I eat. Somebody asked me in the comment section why I eat sesame oil since it contains quite a bit of PUFAs, and noticing this was indeed so, I was going to remove it from my diet altogether. However, doing some reading I found that sesame oil seems to reduce markers of lipid peroxidation, so I kept it on the menu. I just use it for taste, however, so my intake of sesame oil is very low anyway.

Depending on my daily menu, anywhere between 50 to 70% of my total calorie intake is from fat. My daily menu has changed a bit, but percentage of fat is still the same. Most of this is saturated fat, which has been given a bad rep for reasons I believe are incorrect. I began reducing grain products and increasing my saturated fat intake years ago, and it hasn't killed me yet. In fact, my HDL has increased and my LDL has decreased on this diet. Triglycerides are not bad but could be better – a testament to my main vices, beer and wine.

There is one cereal grain I regularly eat, however: rolled oats. They're a convenient source of beta-glucan, which appears to be good for cholesterol and avoiding heart disease, and they don't contain gluten. Oats also contain quite a bit of quality protein. I used to eat them with milk and berries, but then switched to a combination of heavy cream and water to reduce my consumption of lactose and galactose (which easily form advanced glycation endproducts, AGEs). Now, I've stopped adding even heavy cream, because milk protein seems to interfact with the polyphenols in berries. So it's a mixture of coconut milk and water nowadays – not as good as cold milk, but still pretty good.

As for red meat, despite how it's portrayed in the media these days, I'm not convinced that meat consumption is harmful. Indeed, a recent review supports the hypothesis that processed meat, not meat in itself, may be harmful. The biggest problem I used to see with meat is the generation of AGEs. Though there is disagreement just how harmful consuming AGEs with food are, I tried to minimize the potential damage by avoiding overcooking and taking supplements. I no longer think AGEs in meat are a huge problem, however – more on this later. The reason I don't eat huge portions of meat like I used to is because of the high protein content.

And finally, the beverage department. I still love my daily coffee, which I drink 1-2 cups per day. Coffee has some nice health benefits too. Green tea is obviously staying on the menu; the studies showing positive health effects just keep on piling up. All in all, beer doesn't really belong to the "eating healthy foods" category, but even beer does contain some good stuff.

As you may recall, I used to drink yerba mate with meals to reduce the formation of AGEs. It's since come to my attention that yerba mate is carcinogenic at higher doses, so I now drink it only rarely. Green tea or black tea are safer bets, despite somewhat contradictory results in reducing AGEs and ALEs.

Main changes from v1.0: decreased egg intake, changes in the use of fats and oils, reduced yerba mate consumption, avoidance of lipid peroxidation.

A note on diet tweaking

It's much easier to point out things that are wrong in various foods than it is to prove something is healthy. These days, I'm more wary of advertising my diet as the best choice for everyone than I was before. Part of the reason is that the more I read and learn about nutrition, the more complicated everything becomes.

Case in point: I used to tell people vegetables are bad because, as an evolutionary strategy, they produce toxins to protect them from being eaten (which is true). Now, having learned of the importance of hormesis, I think vegetables are good because of those same toxins! I was also a huge fan of eating fruit (especially organic fruit) at one point, because it seemed to make sense from an evolutionary point of view. The, I got a little skeptical towards them because of their fructose content. Now, I think the benefits may outweigh the negatives.

All this, however, doesn't stop me from wanting to find the optimal diet for longevity. On the contrary, it's a healthy reminder not to get too emotionally attached to my health regimen, and to be ready to admit mistakes and make alterations as I learn more.

Going without food

The third key component of my diet used to be intermittent fasting. I stated in the first version of this post that "I may change my mind in the future, but for now I expect periodic food deprivation to remain in the regimen." That is still true to some degree: I no longer do a 24/24 hour cycle of fasting and eating, but I don't make it a point to eat three meals with snacks a day either. I often skip breakfast and lunch and eat only dinner.

The thing that lured me to try intermittent fasting was that there are studies suggesting that all or most of the benefits of chronic calorie reduction can be had by alternating zero calories with double the normal calories every 24 hours. While I no longer believe that IF is equivalent to CR, I do think that fasting in general is beneficial. An improved insulin sensitivity is a known result of intermittent fasting. Insulin sensitivity is associated with longevity, and among supercentenarians, insulin sensitivity is common.

Perhaps a more interesting thing about fasting is that it increases autophagy, a process in which the cell consumes a part of itself for energy. This can happen during ordinary cell maintenance, or when the body is deprived of nutrients. Since improved autophagy is at least in part why caloric restriction works, this makes other, less demanding forms of nutrient deprivation attractive options.

The reason I stopped doing strict IF is because I don't think there is much evidence that fasting for 24 hours and then eating for 24 hours is somehow optimal in itself. Most importantly, IF does not extend lifespan in most studies. Why IF is not equivalent to CR is not clear, but recent studies suggest protein may have a lot to do with it. My intermittent fasting diet resulted in huge meals with lots of protein, and I now suspect that this may have diminished much of the potential benefits.

Main changes from v1.0: no more 24/24 intermittent fasting, no more huge protein-heavy meals.

Supplements

The most important supplement in my regimen is vitamin D3. Most people are deficient in vitamin D, and the health benefits are so overwhelming that if there's one supplement I would recommend spending money on, it's vitamin D3. I usually take 5,000 IU of vitamin D3 daily, and at last check, my levels were at 45 ng/mL, which is in the optimal range. Now that it's summer, I'm taking 2,500 IU daily. I know some people take the same amount all year round, but since I do spend some time in the sun, I don't want to overdo it.

One of the supplements that has remained in the regimen since last time is vitamin K2, which is sort of a newcomer in the supplement scene but nonetheless has some impressive studies behind it. I'll write more about it in the future, but here's one study of interest for men: dietary vitamin K2 may reduce prostate cancer. Since fermented dairy products, which I'm not sure are the best choice for health otherwise, are the best dietary source of vitamin K2, I'm taking supplements instead. At the moment, I take 90 mcg of MK-7 (Jarrow MK-7) and 5 mg of MK-4 (Carlson Labs Vitamin K2) every third day in an attempt to find a balance between affordability and the long serum half-life of vitamin K2.

I used to take a tablespoon of fish liver oil daily, because it has lots of omega-3 fatty acids in bioavailable form (EPA and DHA) and almost no omega-6 fatty acids. A higher dietary ratio of omega-3 to omega-6 seems to be very beneficial in general, and fish oil has been shown to decrease inflammation. A commonly quoted optimal ratio is between 1:1 and 1:4, which seems to be close to how our paleolithic ancestors ate. As part of my plan to avoid excess PUFAs, I've dropped fish liver oil from the menu. I'm currently in the process of weighing the pros and the cons; it may be that a tablespoon per day will prove to be worth it in the end.

I also used to take resveratrol with quercetin during fasts to increase autophagy. I would still continue to take them, but unfortunately I can't afford all the supplements I might like to take (including AOR Ortho-Core, which is off the list for the time being), so I take resveratrol only occasionally. Meanwhile, I'm on the lookout for other things that increase autophagy. Curcumin is a cheap alternative, and it has other health benefits too, which is why I add turmeric to most of my foods.

Since my damn blender keeps leaking from the bottom, I'm no longer making smoothies every day like I used to. So these days I just add some ground flax seeds to my rolled oats for the flax lignans. Flax lignans may prevent hair loss, among other health benefits. Some people prefer to take them in supplement form, but flaxmeal is a cheaper and equally effective way to consume flax lignans. For best effects, they should be consumed twice a day with ~12 hours in between. Other things I do to prevent hair loss is use shampoos with ketoconazole and piroctone olamine.

Main changes from v1.0: no more fish liver oil, some supplement cutbacks due to costs, increased curcumin intake.

Exercise

My exercise routine is probably the weakest part of my regimen, compared to how much effort I put into diet and supplements. In the summer, I run for 30-45 minutes once a week to get some aerobic exercise (I should start again, since summer is here!) The goal is to keep the heart and lungs healthy, reduce blood pressure, and improve mood. In the winter, when it gets too cold for running outside, I go to the gym for strength training instead. Strength training reduces the risk of injury, prevents osteoporosis, supports joint health, and prevents muscle loss resulting from aging.

I also practice martial arts, which combines aerobic and strength training, to a degree. The main reason for me, however, is that it provides me with a basic set of self-defense skills and improves coordination. With aging, there is usually an increased fear of falling and hurting oneself – something children naturally don't have. Getting thrown around every week is a way to maintain a healthier attitude towards my body and prevent an irrational fear of getting hurt. I want my mind to rule over my body, not the other way around.

Main changes from v1.0: none.

Brain training

Any anti-aging regime should also take into account the importance of maintaining mental health. It doesn't take a genius to see that people who use their brains actively retain their cognitive abilities far longer than those who are passive.

One of the ways I keep the rational side of my brain fit is reading scientific papers and writing about them on this blog. I like logical problems in general, and I think practicing problem-solving skills are important for everyone, whether it's through work or hobbies. To train the creative side, I do things like play instruments, compose music, and read and write fiction.

My biggest problem is and always has been rather poor short-term memory. I don't know whether it's because my mind is always occupied with a zillion things, but it's more than once that I've gone to the grocery store to buy something I need and come back with something else entirely. This kind of absent-mindedness seems to run in the family. I believe it can be improved through training, however. The memory game experiment intends to increase IQ, but it improves short-term memory as well (I've pretty much forgotten about this experiment lately, by the way – I'll have to start playing again!)

Main changes from v1.0: none.

Quick summary of the health regimen

As a part of my diet, I regularly eat the following foods:

- Meat, fish
- Olive oil, palm oil
- Butter
- Vegetables, berries, fruit, oats, dark chocolate, coconut milk
- Coffee, tea, wine, beer

I limit or avoid eating the following foods:

- Grain products like pasta, bread, and rice
- Fruit juices, candy
- Vegetable oils high in PUFAs

In general, my diet is high in fat and lowish in carbohydrates. I consume saturated fat and monounsaturated fat liberally but limit polyunsaturated fats.

My supplement regime consists of the following:

- Vitamin D3: 2,500-5,000 IU daily
- Vitamin K2: 90 mcg of MK-7 and 5 mg of MK-4 every third day
- Varying amounts of green tea daily
- Flax lignans: 1-2 tablespoons of ground flax seeds daily

My physical health regime consists of martial arts, running (in the summer), and strength training (in the winter). For mental health, I do things that train the creative and logical sides of the brain.

For more information on anti-aging methods and living longer, see these posts:

Anti-Aging in the Media: New York Times on Caloric Restriction and Resveratrol
How to Live Forever: My 5 Steps to Immortality
L-Carnitine, Acetyl-L-Carnitine and Cognitive Function in Humans
Caloric Restriction Improves Memory in the Elderly

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The Many Health Benefits of Rooibos Tea

Oxidation gives rooibos its familiar reddish colour. (Photo by Smaku)

The herbal tea made from rooibos has been a popular drink in Southern Africa for generations. The plant, Aspalathus linearis, is grown only in a small area in the Western Cape province of South Africa, but during recent years rooibos has become popular in other parts of the world as well.

Though not technically a tea, the infusion made from oxidised rooibos leaves is commonly referred to as rooibos tea. Traditionally, it is enjoyed hot with a slice of lemon and sugar or honey, but iced tea versions and even a rooibos espresso made from concentrated rooibos are apparently gaining popularity.

While many people have acquired a taste for rooibos and know that it is considered something of a health drink, most of us are clueless as to what exactly the health benefits of rooibos are. In this post, we'll review what the studies say on rooibos tea.

The antioxidant activity of rooibos tea

Like regular tea, rooibos tea contains flavonoids which act as antioxidants. While the most beneficial flavonoids of green tea are catechins such as epigallocatechin gallate (EGCG), the main flavonoids in rooibos tea are aspalathin and nothofagin. One in vitro study found that aspalathin is even more effective at scavenging free radicals than EGCG (link) – a rather surprising result, given that just about everyone knows about antioxidants in green tea but not in rooibos tea. All in all, green tea still seems to beat rooibos tea in antioxidant activity, however (link).

The second flavonoid tested, nothofagin, was not as effective as quercetin but still potent. Oddly enough, an older study found that aspalathin and nothofagin can also act as pro-oxidants under certain in vitro conditions (link). The authors comment:

Fermentation (i.e., oxidation) of rooibos decreased the pro-oxidant activity of aqueous extracts, which was contributed to a decrease in their dihydrochalcone content. The in vitro pro-oxidant activity displayed by flavonoid-enriched fractions of rooibos demonstrates that one must be aware of the potential adverse biological properties of potent antioxidant extracts utilized as dietary supplements.

This is not a unique case, however. Vitamin C, probably the most famous antioxidant, has also been said to act as a pro-oxidant in some conditions in vitro; there is much less evidence to suggest it does so in vivo, however (link).

Feeding normal, healthy rats given rooibos tea instead of water had significantly higher serum superoxide dismutase (SOD) levels than the control rats (link). They also had less DNA damage, a result that confirms the findings of an earlier study (link). Futhermore, when the rats were given dextran sodium sulfate to induce colitis, the rooibos group had higher SOD levels, and the drop in hemoglobin levels seen in the control group was prevented. Thus, rooibos tea seems to be anti-inflammatory and have the potential to prevent DNA damage.

The cardiovascular benefits of rooibos tea

Due to their effects on vasodilation and vasoconstriction, angiotensin I-converting enzyme (ACE) inhibitors and nitric oxide (NO) are used to treat conditions such as high blood pressure and heart failure. In one study, the effect of green tea, black tea and rooibos tea on ACE and NO was compared in healthy human volunteers (link). None of the three had a marked effect on NO concentration, but both green tea and rooibos tea inhibited ACE activity, suggesting that they have cardiovascular benefits. This is in contrast to an earlier in vitro study which found that only green tea and black tea inhibited ACE (link).

Closely related to cardiovascular disease is diabetes. The good news is that that rooibos tea may help with this as well. In a mouse model of type 2 diabetes, aslapathin suppresses the increase in fasting blood glucose levels. It also improves glucose tolerance, apparently through stimulating glucose uptake in muscle tissues and insulin secretion from the pancreas (link). Drinking rooibos tea during a meal may not be a bad idea.

Rooibos tea for liver disease and respiratory problems

In rats, rooibos tea aids in liver tissue regeneration after prolonged intoxication. Compared to the rats receiving water during the regeneration period, the rooibos group had less fibrotic tissue in their livers and lower tissue malondialdehyde levels. The authors conclude that rooibos tea "can be recommended not only for the prevention but also as a co-adjuvant for the therapy of liver diseases."

Rooibos tea also has therapeutic potential for respiratory ailments. According to a study on rats, in addition to lowering blood pressure, rooibos tea is both a bronchodilator and an antispasmodic (link, link). This helps explain why rooibos tea is commonly used for gastrointestinal and respiratory problems. The flavonoid chrysoeriol seems to be mainly responsible for the bronchodilator and antispasmodic effect.

Rooibos extract fights HIV

Rooibos tea extract seems to be helpful in antigen-specific antibody production by increasing interleukin-2 (IL-2) production in vitro and in vivo (link). According to the authors, rooibos tea intake "may be of value in prophylaxis of the diseases involving a severe defect in Th1 immune response such as cancer, allergy, AIDS, and other infections."

Another study found that an alkaline extract of rooibos tea leaves suppressed HIV-induced cytopathicity (link). Green tea extract, on the other hand, was ineffective. The authors conclude that HIV infection may be suppressed by the daily intake of the alkaline extract of rooibos tea. Note that the extraction mechanism is important here, because regular rooibos tea does not have anti-HIV activity (link). See the abstracts for details.

Rooibos tea, lipid peroxidation and brain aging

The uncontrolled oxidation of lipids, which can happen during cooking or inside the body, leads to the formation of advanced lipid peroxidation end-products (ALEs). The accumulation of such products is one of the types of damage that occurs with aging.

Lipid peroxides also accumulate in the brain. Rooibos tea may help prevent this damage, however. Rats given rooibos tea instead of water accumulate significantly less aging damage in the brain than rats given water (link). In fact, the 24-month old rats given rooibos tea for most of their lives had brains similar to young 5-week-old rats. This is quite a remarkable result.

One study found that out of the flavonoids tested, quercetin and EGCG (found in green tea) were the best inhibitors of lipid peroxidation, while aspalathin had a similar potency as catechin (link). Nothofagin was of no use here, however. Since polyunsaturated fats or PUFAs are especially prone to form ALEs, it seems like a cup of green tea or rooibos tea with a meal containing polyunsaturated fats might be useful.

The difference between red and green rooibos tea

Typically, rooibos leaves are oxidised before they are used to make rooibos tea. This process, which is not exactly the same as the fermentation process used in making black tea, gives them the familiar reddish-brown color and the slightly sweet taste. However, unoxidised rooibos tea is also available, if you know where to look. The color and taste are quite different; I personally prefer the red version, but green rooibos tea is not bad either.

Like in the case of regular tea, the oxidation process also affects the flavonoid content of the tea. Unoxidised rooibos tea contains more about twice as much total flavonoids as oxidised tea and 10-fold higher levels of aspalathin and nothofagin (link, link). In the studies that have directly compared the two, the unoxidised version seems to generally come out on top. For example, unoxidised rooibos tea seems to protect rats from liver cancer more effectively than oxidised tea (link). The antimutagenic activity of the two depends on the mutagen in question, however (link).

Summary

The health benefits of rooibos tea seem to be mostly due to the flavonoids aspalathin and nothofagin, although other compounds in rooibos may also play a part. Here's a summary of the benefits:

• Acts as an antioxidant and increases SOD levels
• Prevents DNA damage
• Cardiovascular protection through ACE inhibition
• Suppresses fasting glucose levels
• Improves glucose uptake and insulin secretion after a meal
• Aids in liver tissue regeneration
• Lowers blood pressure
• Acts as a bronchodilator and antispasmodic
• Inhibits lipid peroxidation and brain aging
• Rooibos extract improves immune defects such as HIV

Since nothofagin and especially aspalathin are not really found in any other plant, rooibos tea looks like a valuable addition to one's health regimen. Even people who are not fans of green tea usually like the taste of rooibos tea. Since rooibos contains no caffeine, it can be also enjoyed in the evening.

For more information on various teas and health, see these posts:

Hibiscus Tea Lowers Blood Pressure
Tea, Coffee and Cocoa: All Good for Your Teeth
Yerba Mate Inhibits AGE Formation
Drinking 3 Cups of Green Tea Increases Plasma Antioxidant Activity in Humans by 12%

Read More......

Two Brave Men Who Ate Nothing But Meat for an Entire Year

Stefansson and Andersen make paleo dieters look like vegans. (Photo by sheilaz413)

Low-carb diets and paleolithic nutrition are all the rage these days, and for good reason. Compared to the Standard American Diet, both of them are superb.

Few of us would dare to take the two to their extreme, however. Giving up sugar and wheat is one thing, but what about giving up everything except meat? Yes, I'm talking about an ultra low-carb diet with even foods like nuts and berries removed. Unsurprisingly and understandably, studies on the long-term effects of such a diet are severely lacking.

There is at least one study that did just this, however. If the diet brings the Eskimos to mind, it's no coincidence. You may have heard of Dr. Vilhjalmur Stefansson – the Canadian ethnologist who spent more than a decade with the Inuit during his arctic explorations in the beginning of the previous century. For nine of these years, he lived almost exclusively on fish and meat (you can read about his experiences here). At the time, this was considered heresy and life-threatening, just as it is today (note that Stefansson apparently refers to both fish and meat with the word "meat"):

A belief I was destined to find crucial in my Arctic work, making the difference between success and failure, life and death, was the view that man cannot live on meat alone. The few doctors and dietitians who thought you could were considered unorthodox if not charlatans. The arguments ranged from metaphysics to chemistry: Man was not intended to be carnivorous - you knew that from examining his teeth, his stomach, and the account of him in the Bible. As mentioned, he would get scurvy if he had no vegetables in meat. The kidneys would be ruined by overwork. There would be protein poisoning and, in general hell to pay.

To the surprise of many (including Stefansson himself), he suffered no health problems during his decade of pure carnivorism. When he told people of his amazing experiences, he was met with skepticism from medical authorities who asked him to undertake a study that would replicate the results. He and a fellow explorer named Andersen agreed to eat an all-meat diet for an entire year in a closely observed setting.

Composing a diet of nothing but meat and fat

This time, however, the diet was even more radical than the traditional Eskimo diet, which is based on fish and includes a small amount of berries and vegetables – not a lot, but enough to keep them out of ketosis most of the time. Furthermore, since fish is high in omega-3 fatty acids, you could argue that it's all those good fats that keep the Eskimos free of disease.

But how could anyone subscribing to conventional health wisdom explain thriving on a diet consisting solely of red meat? No vegetables, no fruit, no vitamin supplements. Nothing. Just meat and animal fat.

The results of this fascinating study were published in 1930 in the Journal of the American Medical Association (link). At the beginning of the experiment, Stefansson was given only lean meat at the request of his supervisors. This was to confirm Stefansson's bad experiences with low-fat meat; during his explorations, there had been periods during which fat was not readily available and which lead to diarrhea and nausea in a few weeks. This time, the illness kicked in much earlier:

As said, in the Arctic we had become ill during the second or third fatless week. I now became ill on the second fatless day. The time difference between Bellevue and the Arctic was due no doubt mainly to the existence of a little fat, here and there in our northern caribou - we had eaten the tissue from behind the eyes, we had broken the bones for marrow, and in doing everything we could to get fat we had evidently secured more than we realized. At Bellevue the meat, carefully scrutinized, had been as lean as such muscle tissue can be.

After fat was added back into the diet, a full recovery was made in two days. The authors of the study describe the diet from then on:

The meat used included beef, lamb, veal, pork and chicken. The parts used were muscle, liver, kidney, brain, bone marrow, bacon, and fat.

Thus, fat played an important part in their diets. According to the authors, Andersen usually ate beef, while Stefansson often chose lamb. Both men ate about 800 grams of meat per day in 3-4 meals. The protein contents ranged from 100 to 140 grams, the fat from 200 to 300 grams, and carbohydrates from 7 to 12 grams. In calories, the percentages were 15-25% protein, 75-85% fat, and 1-2% carbohydrate. The carbs came solely from the glycogen of the meat, making this not so much a low-carb as a no-carb diet. In addition to water, coffee and tea were allowed throughout the period.

Health markers after one year

Examinations at the end of the observation showed that both men were healthy while on the diet. The authors write:

There were no subjective or objective evidences of any loss of physical or mental vigor. The teeth showed no deterioration and gingivitis had disappeared. There was, however, an increase in the deposit of tartar on the teeth of [Stefansson]. Bowel elimination was undisturbed.

Though neither man was overweight to begin with, and weight loss was not the goal of the experiment, both men lost a few pounds during the year. This was despite the fact that calorie intakes ranged from 2,000 to 3,100 kcal. Stefansson averaged about 2,650 kcal (2,100 from fat and 550 from protein), while Andersen averaged 2,620 kcal (2,100 from fat and 510 from protein).

Given that Stefansson, the taller of the two, was 180 cm (5 feet 11 inches), and both of them were fairly sedentary, this represents a significant amount of calories without any weight gain. During the first weeks, weight loss was more significant, apparently due to a shift in the water content of the body. Both men appeared "ruddier" at the end of the experiment than at the beginning.

Blood pressure did not increase in either subject. Stefansson's blood pressure remained at 105/70 mm. throughout the study, while that of the other subject decreased from 140/80 to 120/80 mm. Salt intakes were fairly low.

No physical fatique or problems sticking to the diet were experienced by the two men. Only when the protein content of the diet increased substantially (45% of calories, 55% fat) did problems with digestion occur. Replacing excess protein with fat (20% protein, 80% fat) quickly resolved them, however.

No clinical evidence of vitamin or calcium deficiency was noted, despite the diet being both acidic and low in calcium. In addition, the mild gingivitis Stefansson had suffered from, cleared up entirely during the meat diet. Interestingly, Andersen reported that his hair stopped falling out shortly after the meat diet was started; Stefansson also noted his hair started growing thicker and his scalp was healthier.

Acetone bodies in daily averages per experimental period ranged from 0.4 to 7.2 gm, with the maximum excretion measured during the year being 12.3 gm. The acidity of the urine showed a 2-to 3-fold increase, which is consistent with the highly acidic nature of the diet. A slight increase in uric acid nitrogen was found during the first three months only.

All in all, no evidence of irritation to the kidneys was found – despite the fact that these men were in ketosis practically for an entire year. A higher degree of ketosis was noted when the fat content of the diet increased and the protein content decreased. Acetone bodies quickly disappeared when carbohydrates were introduced into the diet.

In general, the men were in ketosis whenever the ratio of fat to carbohydrates was over 1.5. With the extremely small amounts of carb in their diets, no definite relation between the amount of acetone bodies and the ratio of fat to carbs was found. Stefansson's friend, who was smaller and had less subcutaneous fat, had the highest sustained ketosis.

Seven years after the meat diet

In 1935, one of the authors published an article titled "A Year's Exclusive Meat Diet and Seven Years Later", in which he revisits Stefansson's case (link). First, he summarizes the main points of his earlier article from 1926, titled "The Effects of an Exclusive Long-continued Meat Diet". The following medical facts regarding Stefansson's life during his explorations are listed:

1. He spent altogether altogether eleven and one-half years within the Arctic Circle.
   
2. He lived for a number of days, totaling nine years, on an exclusive meat diet.
   
3. He lived for nine successive months on an exclusive meat diet.
   
4. He reached his maximum weight while subsisting on meat (fish).
   
5. His sense of physical and mental well being was at its best during that period of his life.
   
6. He found that the exclusive meat diet worked as well when he was inactive as when active, and as well in hot weather as in cold.
   
7. Constipation was never present. One month's entire absence from exercise produced neither constipation nor muscular weakness. (Stefansson avers that not a single case of constipation was observed in 600 exclusively meat-eating Eskimos for a period of three years).
   
8. His hair thickened, and his scalp became healthier.
   
9. Tooth decay was apparently much less rapid.

Seven years after the meat diet study, the author examined Stefansson again, who apparently had reacquainted himself with some aspects of the Western diet. Instead of eating only meat, he was now eating a breakfast of one egg, bread and coffee, and a dinner and supper consisting of a moderate amount of meat, vegetables, and some cheese. His fruit and milk intake remained negligible.

During this period, Stefansson had put on quite a bit of weight. He now weighed 84 kg, compared with 70.8 kg in 1922 and 72.5 in 1928. His hair was as thick as before, but his gingivitis had returned. Blood pressure was up to 120/80 mm. All in all, the author states Stefansson was in excellent general health. Looking at the numbers, however, it seems that he was doing better on his monotonous carnivore diet.

While it would be interesting to replicate the study with a larger sample size and have more health markers measured than the ones used in the study, it is quite remarkable to see that a diet consisting of nothing but meat and animal fat is both feasible and, apparently, healthy. It also lends support to the importance of having a sufficient amount of fat in the diet, especially when protein is present in significant quantities.

For more information on diets and health, see these posts:

Red Meat and Mortality: A Closer Look at the Evidence
A Typical Paleolithic High-Fat, Low-Carb Meal of an Intermittent Faster
SAs, MUFAs vs. PUFAs: Fat Storage Depends on Type of Fatty Acid in Rabbits
Protein, Vitamins and Wound Healing

Read More......

The 7 Types of Aging Damage That End up Killing You

The longer you live, the more time you have to explore the world. (Photo by iko)

If aging merely meant the passage of time, there'd be nothing wrong with it.

In fact, it'd be a good thing. The older you got, the more things you would know, the more skills you would've acquired, the more experiences you would've had, and the more people you would've met. All this while retaining the strength and vigour of youth. Doesn't sound too bad.

The problem is that what aging really means is the passage of time accompanied by a set of degenerative biological processes that harm the abilitity of our bodies to function and eventually cause us to die. What good is all that knowledge and all those experiences if you can't remember any of it? What good are all those skills when you're no longer able to use them?

We don't really know why we age. That's an interesting question in its own right, but it's beyond the scope of this post. The point of this post is to take a closer look at the biological processes that accompany the passage of time and together form the seven classes of aging damage.

It is because of this process of biological decay that we grow old. Not old the way vampires are "old" yet still magically look the same, but the way people and animals are old – fragile, weak and sick. To be clear, despite what most people tell themselves, there is nothing good about growing old, because all it really means is a cumulative and irreversible increase in fragility, weakness and sickness.

The good news is that despite decades of studying aging, we have identified only seven types of primary damage to our bodies from aging. The rest are secondary consequences of primary damage. If you prevent the primary damage from occurring, you will prevent the secondary consequences as a result, but not vice versa.

And why is it a good thing that there are seven causes of aging? Because it means that the aging process is not a complete mystery anymore. Or rather, the consequences of the aging process are not a complete mystery to us. Even though we don't have a clear explanation for why these seven types of damage occur in the first place (i.e. why are we not born biologically immortal?) we have a pretty good understanding of how they work.

And if we know all the things that are going wrong with our bodies as we age, we can begin to fix them.

The three approaches to the sinking boat problem

Imagine that the human body is a boat. For many years, the boat sails without a problem. But then, somewhere in the middle of the ocean, there's a problem: a hole has appeared in the bottom, and the boat is going to sink.

Now imagine that on that boat, there are three people: an architect, a mechanic, and a museum keeper. You go to them and ask each one in turn what could be done to fix the situation.

The architect has no experience in repairing boats. He is interested in understanding the nature of boats. He has heaps of drawings of boats and calculations for which kind of materials are suitable for a specific type of boat, but he doesn't actually build the boats. His suggestion is to study the boat carefully to understand the exact reasons that caused the hole to appear. If we understand the causes, he figures, we are better equipped to fix the problem.

You know there's no time for all that because the boat is sinking fast, so you go to the museum keeper. He runs a museum with old boats on display and has some experience on renovating worn down boats for museum use. He's not really interested in making them actually usable at sea; all they need to do is look good. His suggestion is to just let the boat sink, because sink it will, and then come back later to drag it from the bottom of the ocean and put it on display.

That doesn't feel like such a great idea either, so you turn to the mechanic. He has no idea where the hole came from, isn't familiar with the exact type of boat, and is in no hurry to visit the ocean floor. But he does have a plan: have two of you scoop the water back into the sea as fast as possible, while the other two find something to fill the hole with. There's no guarantee that another hole won't appear later on, but at the very least, his plan is going to buy you extra time.

At this point, extra time sounds pretty damn good, so you go with the mechanist's suggestion and grab the nearest bucket to start scooping.

Gerontology, engineering and geriatrics

There are three approaches to the study of aging: gerontology, engineering and geriatrics. In the boat metaphor above, the architect is the gerontologist, the mechanic is the engineer, and the museum keeper is the geriatricist.

Broadly defined, gerontology is the study of aging. It encompasses a wide range of subfields, but for the purposes of this post, biogerontology is the subcategory of interest. Biogerontologists seek to understand the biological processes that cause aging. A fascinating field of study, for sure, but as the boat example illustrates, when you're the one actively falling apart, perhaps a bit too theoretical.

Geriatrics, on the other hand, is a branch of medicine focused on the health care of the elderly. The emphasis is on treatment rather than prevention. One could even say it's about alleviating the symptoms rather than reversing the damage, much less fixing the cause. The problem is that the geriatricist has no interest in helping you unless your boat is already beyond repair.

The engineering approach to aging is to fix the damage as it occurs. The purpose is not to fully understand all the reasons that the damage happens in the first place, interesting as it may be; it's enough to know that it's there. Rather, the emphasis is on periodic repair and maintenance, so that even after years of use, the boat still looks, feels and sails like new. And if during those extra years of use maintenance buys us we learn something new about how to make boats more resistant to damage, all the better.

To me, the engineering approach is a matter of priorities. Yes, it would be fascinating to understand the complete workings of the human body, but it's much less fascinating to die trying now than it is to live significantly longer and find out later. Besides, the more years you have left, the more time you have for things like research and thus the more chance of succeeding in mapping out every possible metabolic pathway. Life should be our first priority in everything, because death cuts everything else short.

The seven deadly sins of aging

Without further ado, let's take a look at what the seven types of aging damage are and what we think can be done about them. Again, while identifying the different ways in which aging manifestates itself doesn't really explain why the damage happens, or even why there are exactly seven types of damage, it does provide us with clear goals for an engineering approach to life extension.

This approach of focusing on rejuvenation rather than slowing down aging itself is referred to as SENS, or Strategies for Engineered Negligible Senescence, a term originally coined by Aubrey de Grey in his book The Mitochondrial Free Radical Theory of Aging. Each of the SENS strategies targets one of the seven types of damage, listed below.

1. Cell loss and shrinking tissue

Worn out cells in the body are usually replaced by cell division. However, as we age, some of the cells we lose can no longer be replaced or they are replaced very slowly, which means that cells are being lost faster than they are produced.

In skeletal muscle, cell loss means shrinking tissue and weaker muscles. In the heart muscle, it means a more fragile heart. In the brain, it means a loss of neurons and causes a host of mental problems. Currently, one of the best approaches to cell loss is exercise, but its effects are nevertheless very limited.

The solution: stimulating cell division or introducing new cells (repleniSENS)

2. Mutations in the cell nucleus

Two types of changes in our chromosomes occur as we age: mutations and epimutations. The former are changes to the DNA itself, while the latter are changes to the propensity of the DNA to be decoded into proteins.

In some cases, changes to the DNA can lead to the formation of cancer. Non-cancerous mutations and epimutations do not in most cases contribute to the aging process, and in the rare cases that they do pose a problem, they are taken care of by other strategies (repleniSENS and apoptoSENS), so we don't have to worry about them at this point. Cancer, however, is definitely a problem, as anyone who's looked at mortality statistics in the Western world can testify .

The solution: removing the genes needed for telomerase (OncoSENS)

3. Mutations in the mitochondria

Mitochondria are known as the "power plants" of cells, because they play a key role in energy production. They also control cell growth and the cell cycle. Mitochondria contain their own mitochrondrial DNA (mtDNA), which encodes a small but important part of the proteins in the mitochondrion.

The problem is that the mitochrondrial environment is highly oxidative, and the repair mechanisms are much less sophisticated than those in the cell nucleus, which contains most of the DNA. The result is that mitochondria are very vulnerable to the accumulation of mutations, which is thought to accelerate aging. Therefore, preventing the accumulation of mitochondrial mutations requires a strategy of its own.

The solution: moving the DNA into the cell nucleus for better protection (MitoSENS)

4. Cells that refuse to die

Sometimes cells can acquire a state in which they are no longer able to divide but refuse to die, causing damage to neighboring cells. There are three classes of cells that can go into this harmful state: visceral fat cells, senescent cells and immune system cells. The problems that the accumulation of these cells cause are insulin resistance, tissue degradation, and vulnerability to infection.

Normally, the body is able to get rid of such harmful cells through apoptosis, a signal for the cell to kill itself. When the cells stop responding to these signals, other methods are needed to destroy them. While surgery can be used to remove visceral fat, the main alternatives to destroying senescent and immune system cells are injecting something to force apoptosis or stimulating the immune system to kill the cells.

The solution: forcing cell suicide or using the immune system to kill target cells (ApoptoSENS)

5. Tissue stiffening from crosslinks

The body is much better at keeping the insides of cells clean than it is maintaining proper functioning outside the cells. Inside the cells, proteins are regularly destroyed and rebuilt to keep things running smoothly, but outside, some proteins are recycled very slowly or never. With time, these long-lived proteins can run into problems.

Chemical reactions can sometimes cause two proteins to form a chemical bond known as a crosslink, which hinders their ability to slide across or along each other. Advanced glycation endproducts (AGEs) are probably the most famous example of crosslinks. When too many crosslinks occur, tissues lose their elasticity and problems arise. In artery walls, for example, tissue stiffening causes an increase in blood pressure. Breaking these crosslinks is needed to maintain a youthful state.

The solution: using specific enzymes or proteins to break crosslinks (GlycoSENS)

6. Junk outside the cells

This is another form of junk outside the cells that accumulates with aging, but it differs from crosslinks in that it has no useful function whatsoever. This junk should be cleared out of the body, but as in the case of death-resistant cells, the body is not able to digest or remove the material.

An example of junk outside the cells are the amyloid plaques in the brains of Alzheimer's patients. This web-like material accumulates in everyone's brains with age, but problems become visible only after a certain threshold has been reached. In supercentenarians, extracellular junk is one of the biggest killers.

The solution: stimulating the immune system to clear out the junk (AmyloSENS)

7. Junk inside the cells

As mentioned earlier, the body is fairly good at breaking break down proteins and other molecules in the cell which are no longer useful. However, sometimes these molecules have gone through chemical changes that makes the cell unable to digest them any longer. They then end up in the lysosome, which is the most powerful place to degrade molecules. If the lysosome is unable to get rid of them, they end up as intracellular junk and stay there practically forever.

In dividing cells this is not too big of a problem, because each division dilutes the junk, and the threshold where problems occur is not reached. But in non-dividing cells, the accumulation of this junk eventually causes the cells to stop functioning correctly. The result is problems such as atherosclerosis, blindness, liver spots, and a host of neurogenerative diseases.

The solution: making the lysosome more powerful to degrade the junk (LysoSENS)

Summary

There you have it, the seven types of aging damage that need to be fixed in order for true rejuvenation engineering to happen. And how do we know the list ends here? Isn't it possible there are other causes we just don't know of yet? Theoretically, yes, but it seems highly unlikely. Here's an explanation taken from the SENS Foundation website:

We can be confident that this list is complete, first and foremost because of the fact that scientists have not discovered any new kinds of aging damage in nearly a generation, despite the facts that research into aging has been slowly accelerating and that we have had ever-increasingly powerful tools with which to investigate the aging body.

Challenging as fixing this damage may be, the fact that we know what we need to do should still leave you with a fairly optimistic view of things. As I've said before, solving these problems is really a question of "when", not "if". And the sooner it is, the better – for all of us.

Even if you're not studying or working in the field, there are a couple of very practical ways to help make these rejuvenation therapies come true in your lifetime. The SENS website has a pretty good list of things with something for everyone, but I'll mention two important ones here.

Money is always needed, so one good option is to donate to the Methuselah Foundation or to the SENS Foundation to support research (and if you're sceptical of donations actually doing anything, here's some good news: a recent target of $16,000 was succesfully reached and exceeded earlier this month for research on using lasers to remove intracellular junk).

Another important thing is to talk to people and spread the word: many people don't have any idea that life extension is not just science fiction anymore. Significantly longer and healthier lifespans are the future, and just how far away this future is depends entirely on us.

For more information on preventing aging, see these posts:

How to Live Forever: My 5 Steps to Immortality
Slowing Down Aging with Intermittent Protein Restriction
Who Wants to Live Forever? Results from a Global Survey
Anti-Aging in the Media: New York Times on Caloric Restriction and Resveratrol

Read More......

Hibiscus Tea Lowers Blood Pressure

A cup or two of hibiscus tea is an effective remedy for hypertension. (Photo by debra solomon)

Hibiscus tea (sometimes called sour tea) is a herbal drink made from the calyces of the Hibiscus sabdariffa flower. It is also commonly mixed with other ingredients such as ginger and sugar to make a chilled beverage known as agua de jamaica or rosa de jamaica.

Hibiscus tea is believed to reduce blood pressure and cholesterol. While there are no studies looking at the effect of hibiscus on cholesterol levels, I did find two studies that showed positive results in treating high blood pressure. In this post, we'll take a look at both papers.

Study methods

In the earlier study, men and women with moderate hypertension were randomly assigned to either an experimental or a control group (link). Inclusion criteria were a systolic pressure of 160-180 mmHg and/or a diastolic pressure of 100-114 mmHg. Mean age in both groups was slightly over 50 years.

The experimental group was given a box of hibiscus tea, while the control group was given ordinary tea (black tea, I assume, though the authors don't say). The participants were instructed to use two spoonfuls of tea in one glass of boiled water at least one hour before measuring blood pressure.

The newer study used sixty diabetic patients with mild hypertension (link). Participants were told to drink either hibiscus tea or black tea twice a day for one month. Blood pressure was measured on days 0, 15 and 30.

Results

After 12 days of drinking a cup of hibiscus tea, the experimental group in the first study showed a 11.2% decrease in systolic pressure and a 10.8% decrease in diastolic pressure, as compared to the first day. The control group showed a slight decrease in systolic pressure but not in diastolic pressure.


The above graph shows the systolic blood pressure of the experimental and control groups. Here is the graph showing changes in diastolic blood pressure:


As you can see, both systolic and diastolic blood pressure went down in those who drank hibiscus tea for 12 days and then increased from day 12 to day 15. This is because after the twelve days, the participants were told to stop drinking tea and measured their blood pressure again after three days.

After stopping tea drinking, there was almost no change in the control group, while the blood pressure of the hibiscus tea drinkers quickly catched up with the control group. Hence, blood pressure was significantly affected by hibiscus tea but only slightly by ordinary tea. Furthermore, the authors speculate that the lowered blood pressure in the control group may in fact have been a result of the health advice given at the beginning of the study.

In the study with diabetic patients, systolic blood pressure went from 134.4 to 112.7 mmHg in those who drank hibiscus tea twice daily for a month. In those who drank black tea instead, systolic blood pressure increased from 118.6 to 127.3 mmHg. No statistically significant changes were seen in diastolic blood pressure in either group.

Mean pulse pressure, which is the difference between systolic and diastolic blood pressure, decreased in the hibiscus drinkers from 52.2 to 34.5 mmHg, while it increased in the black tea drinkers from 41.9 to 47.3 mmHg.

Conclusion

Hibiscus tea lowers blood pressure significantly in patients with mild to moderate hypertension. In one study, both systolic and diastolic pressure were lowered as a result of drinking hibiscus tea, while in another one only systolic pressure decreased.

In diabetic patients with mild hypertension, systolic pressure increased after drinking black tea daily, while diastolic pressure remained the same. In non-diabetic patients with moderate hypertension, both systolic and diastolic blood pressure decreased slightly after drinking black tea.

For more information on tea and blood pressure, see these posts:

Intermittent Fasting with a Condensed Eating Window – Part II: Blood Pressure, Body Weight & Cholesterol
A High-Protein Diet Is Better than a High-Carbohydrate Diet for Weight Loss
Green Tea Extract Increases Insulin Sensitivity & Fat Burning during Exercise
Drinking 10 Cups of Green Tea Daily and Not Smoking Could Add 12 Years to Your Life

Read More......

A High-Protein Diet Is Better than a High-Carbohydrate Diet for Weight Loss

Casein is the main protein in cheese made from cow milk. (Photo by cwbuecheler)

The war over weight loss is usually fought between the low-carb and the low-fat folks, both of whom are absolutely convinced they're right and the other side is wrong. If you've read diet forums, you know what I'm talking about (and if you've read my blog, you know that it's really the low-fat people who are wrong).

Protein, the third macronutrient, is often forgotten in the heat of battle. Putting the question of fat intake aside for a moment, which is better for weight loss, carbohydrates or protein? That is the question Claessens et al. set out to answer in their recent study. They first put obese people on a low-calorie diet to induce weight loss and then divided them into two groups: the high-carbohydrate group and the high-protein group. The idea was to see whether they would gain back the weight they lost during their calorie restriction diet.

Composition of diets

During the first 5 weeks of the study, all of the subjects consumed a liquid diet providing 500 kcal per day. In addition, they were allowed to eat an unrestricted amount of vegetables, except for pulses. All participants lost weight during this period.

During the next 12 weeks, the subjects were told to eat as much as they like but maintain a fat intake of about 30%. The high-carbohydrate (HC) group was told to consume at least 55% of their energy intake as carbs, while the high-protein group was told to eat a diet with at least 25% protein. The HC group was also given a 25 g maltodextrin supplement twice per day.

To compare the effects of so-called slow and fast proteins, the high-protein was further split into a whey protein group and a casein protein group. The distinction between slow and fast proteins is made based on their absorption pattern. Whey protein is quickly absorbed and thus a fast protein, while casein is slowly absorbed and therefore a slow protein. The subjects in the high-protein group were given either 25 mg casein (HPC group) or 25 mg whey (HPW group) twice per day.

At the end of the study, the HC group consumed 63% carbs, 16% protein and 21% fat. Mean total energy intake was 1868 kcal. Both HP groups reported consuming 42% carbs, 35% protein and 23% fat. According to urinary nitrogen excretion, however, the protein intakes of the HP groups were between 27-28%, which means that the difference in protein intake between the groups was probably not as big as one might hope, though it's still significant. Mean total energy intakes were 1848 and 1812 in the HPC and HPW groups, respectively.

Effects on body weight & body fat

During the 12 weeks of ad libitum eating, subjects in the HC group gained weight, while those in the HP groups kept losing weight. Fat mass and waist circumference also increased in the HC group, but decreased in the HP groups. The graphs for body weight and body weight change are shown below (the upward lines are the high-carb group and the downward lines are the high-protein groups).



Thus, despite similar energy intakes, those who ate more carbohydrates gained weight, while those who ate more protein lost weight. Furthermore, despite losing weight, the HP group actually gained fat-free mass.

Effects on blood pressure & cholesterol

Systolic and diastolic blood pressure increased slightly in the HC group, but the increase was not statistically significant. In the HP groups, however, a modest but significant decrease in blood pressure was seen.

Both groups modestly increased their HDL and LDL levels during the 12 weeks. No significant differences were seen between the groups. Triglycerides increased in the HC group but remained constant in the HP group.

Effects on insulin and glucose

Fasting insulin increased in the high-carbohydrate diet group and decreased in the high-protein diet group, but the changes were not statistically significant. Fasting blood glucose increased in both groups, with the increase reaching significance only in the HP groups. With glucagon, the situation was the opposite: the increase reached significance only in the HC group.

It's not entirely clear why the high-protein diet increased fasting blood glucose more than the high-carbohydrate diet. The authors comment:

This may be related to the gluconeogenesis-stimulating and/or glucagon-stimulating effect of high protein intake, which both will lead to increased hepatic glucose output.
-- Although impaired fasting glucose is a risk factor for the development of impaired glucose tolerance and type 2 diabetes in a high-risk population, there is no evidence that elevations of fasting plasma glucose within the normal range, as in the majority of our subject population, are associated with increased risk. Furthermore, no adverse effect of the high-protein diet on HbA1c was found in our subjects.

So, while this is an interesting result that deserves a closer look, I wouldn't be too worried at this point about high-protein diets and glucose levels it as long as your insulin levels are fine.

Conclusion

After a 5-week low-calorie diet, a high-protein ad libitum diet resulted in further weight loss compared to a high-carbohydrate ad libitum diet, which resulted in weight gain. Despite a decrease in body weight, body fat percentage and fat mass, fat-free mass increased in the high-protein groups. Energy intakes were similar in all groups.

Cholesterol levels increased similarly in both groups, but triglycerides increased only in the HC group. Fasting blood glucose increased in both groups, with a larger increase seen in the HP groups. Blood pressure decreased slightly in the high-protein groups.

No significant differences were seen between those eating a casein (slow) protein or a whey (fast) protein supplement.

For more information on carbohydrates, protein and fat in diets, see these posts:

Low-Carb vs. Low-Fat: Effects on Weight Loss and Cholesterol in Overweight Men
A Typical Paleolithic High-Fat, Low-Carb Meal of an Intermittent Faster
The Effects of a High-Fat Diet on Health and Weight - Experiment Conclusion
Caloric Restriction Improves Memory in the Elderly

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