Antioxidants and Intermittent Fasting – Good For Longevity?

Are blueberry antioxidants beneficial for intermittent fasting? (Photo by Simply Bike)

Is it possible to live longer by combining the benefits of intermittent fasting (IF) and plant polyphenols? A new paper claims that taking polyphenol antioxidants during dietary restriction increases the lifespan of mice more than dietary restriction alone. The antioxidants used in the study were blueberry, pomegranate and green tea extracts.

The subject of the paper – "Potentiation of dietary restriction-induced lifespan extension by polyphenols" – is certainly enough grab the attention of anyone interested in life extension. The abstract seems promising too (link). Here's a quote:

Dietary restriction (DR) extends lifespan across multiple species including mouse. Antioxidant plant extracts rich in polyphenols have also been shown to increase lifespan. We hypothesized that polyphenols might potentiate DR-induced lifespan extension. [––] Polyphenol compounds may potentiate IF-induced longevity by minimizing specific components of IF-induced cell stress.

Let's look at these claims in more detail. First off, it's not clear from the abstract what exactly the authors mean by "dietary restriction". The full paper, however, reveals that they use the term to describe pretty much any kind of diet where access to food is limited, including traditional calorie restriction and intermittent fasting.

The longevity confusion

The problem with that opening sentence is that dietary restriction extends lifespan across multiple species only when it equals calorie restriction. That is, you can make a mouse live longer by only feeding every other day, as long as it results in less calories consumed. This is an important distinction, because many people – including longevity scientists – keep propagating the myth that intermittent fasting has the same benefits as calorie restriction. It doesn't. The reason that IF prolongs lifespan in some species is because the animals fail to compensate for the missed calories on their feeding days.

The next sentence is just as problematic. Yes, plant antioxidants have been shown to increase lifespan, but the question is, compared to what? So far, no one has succeeded in exceeding the known maximum lifespan of mice by feeding them antioxidants. Instead, what we see in many studies is that the antioxidant group lives longer than the control group.

The problem is that almost always, neither group lives very long. Poor diets, poor animal husbandry, poor environment – all play a role in how long the animals live. So, in essence, the antioxidants merely make the unhealthy mice a bit healthier. But this is like making a human live 70 years instead of 60 years by giving them some veggies with his daily bread and then claiming that "vegetables extend human lifespan".

Comparing lifespans

That said, there are some interesting figures in the full paper. The graph below shows the survival rates of the three groups; one fed the control diet, the second fed the same diet but only every other day, and the third fed a diet supplemented with polyphenols every other day:

There's a big drop in the survival rate of the control group around 22 months. For the IF groups, the survival curves look a lot better. So how does this compare to the average lifespan of similar mice kept in good laboratory conditions? Here's a graph of age ranges and survivorship of C57BL7/6J mice (the same strain used in this study):

This survival curve is based on a cohort of 150 male and 150 female mice. As you can see, at 28 months half of the mice are still alive. That's about 850 days, which is a pretty normal figure for mean lifespan of this strain of mice in the literature.

Once again, in the antioxidant study the control group dies earlier than is normal. For some reason, half of the mice are dead at 22 months instead of 28 months. One possible reason is the use of a high-fat diet to "mimic the effects of a Western diet", as the authors put it. This seems like a strange idea to me, because a typical Western diet is no more a high-fat diet than it is a high-carbohydrate diet. Furthermore, plenty of humans (myself included) seem to do quite well on a high-fat diet, whereas with mice it's somewhat different.

The survival curve of the IF mice in the first graph is slightly better than that of the normal-fed mice in the second graph. But that is hardly a surprise, given that both the IF group and the IF + antioxidant group had lower body weights than the control group. In other words, the intermittent fasting once again made the mice eat less than the control group, which in turn resulted in a slightly longer lifespan. It's good to keep in mind, however, that with just 10% calorie restriction longer lifespans have been reported in other studies, so the result is not too impressive.

Conclusion

Perhaps the most interesting result is that the IF + antioxidant group lived slightly longer than the IF group. There's no concensus as to whether it's a good idea to combine CR or IF with antioxidants. It may be that plant polyphenols are essential for optimal nutrition and good for activating sirtuins (which play at least some role in longevity), but there is also some evidence suggests that taking antioxidants may interfere with hormesis and thus diminish the effects of CR.

In this study, the antioxidants had a beneficial effect. While the IF diet by itself activated pro-inflammatory pathways, adding plant polyphenols to the diet blocked this effect. The authors identified 20 gene sets that were down-regulated by the addition of polyphenols, most of them related to immune response, inflammation, cell differentation and tumorigenesis. 

This suggests that if you're doing intermittent fasting, adding some blueberries, pomegranates and green tea to your diet may not be such a bad idea. Note, however, than the mice did not have access to polyphenols during their fasting days, so this study tells us nothing about taking antioxidants during fasting. It also doesn't say much about how polyphenols affect regular calorie restriction without IF in humans.

For more information on intermittent fasting and longevity, see these posts:

Lithium in Drinking Water May Lead to Longer Life
Does Intermittent Fasting Increase Lifespan?
Alternate-Day Feeding and Weight Loss: Is It the Calories Or the Fasting?
Slowing Down Aging with Intermittent Protein Restriction

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Guest Post: Natural Alternatives for Arthritis Treatment

Glucosamine is also found in seashells. (Photo by DavidRPhoto)

Guest post by Emily Matthews

Glucosamine sulfate and chondroitin sulfate have long been used as supplements to ease the pain of arthritis. Both compounds are found naturally in animal cartilage and glucosamine can also be found in seashells. A person who wishes to increase the amount of glucosamine and chondroitin in their diet should take them together as supplements, but only from a reputable manufacturer of vitamins and supplements. Medical professionals are uncertain as to the dosage for the average person.

Chondroitin

Chondroitin is a more complex molecule than glucosamine. It's made up of intact or hydrolyzed glycosaminoglycans with attached sugar molecules. Studies from masters degree programs show that it’s not as effective as glucosamine in treating arthritis, as the body doesn’t absorb as much of it; chondroitin is such a large molecule that it's difficult to pass through the normal intestinal barrier. The benefit of chondroitin comes because at least some of it can be broken down into glucosamine in the digestive track.

Glucosamine

Glucosamine is a simple molecule made up of glucose and an amine, which is a building lock of protein. The main effect of glucosamine is to stimulate the creation of glycosaminoglycans, which helps cartilage remain spongelike and act as a cushion between joints. As some people age, their bodies lose the ability to manufacture glucosamine and so the cushioning effect of cartilage is lost. Some studies claim that glucosamine supplements are more effective than placebos or non-steroidal anti-inflammatory drugs in easing arthritis pain

GAIT Trials

In a recent study, the National Center for Complementary and Alternative Medicine conducted the Glucosamine Chondroitin Arthritis Intervention Trial, or GAIT to see if glucosamine and chondroitin sulfate gave any benefits in the treatment of arthritis of the knee. The study was conducted to see if the supplements, used alone or separately, eased the pain of 1583 sufferers of this form of arthritis.

In GAIT, the people who participated in the double blind trial took glucosamine alone, chondroitin sulfate alone, the two supplements together, the prescription drug celecoxib, or a placebo. The results of the trial were that celecoxib significantly reduced the pain of knee arthritis and that glucosamine and chondroitin, taken alone or separately, were no better than the placebo in reducing pain. However, there was a small group of participants with what they described as "moderate to severe pain" who found that the glucosamine and chondroitin sulfate combination reduced their pain significantly.

The efficacy of glucosamine and chondroitin in treating arthritis is uncertain. Glucosamine seems to provide some relief for some arthritis sufferers. Chondroitin is too large a molecule to be absorbed by the body in any appreciable amount. If the glucosamine and chondroitin combination works for some people, it’s probably because enough chondroitin is broken down to increase the effect of the glucosamine.

Emily Matthews is currently applying to masters degree programs across the U.S., and loves to read about new research into health care, gender issues, and literature. She lives and writes in Seattle, Washington.

For more information on glucosamine, chondroitin and arthritis, see these posts:

Green Tea Protects Cartilage from Arthritis in Vitro
Green Tea Protects from Arthritis in Rats
MSM + Chondroitin + Glucosamine for Hair & Nail Growth - Results after Seven Weeks
MSM + Chondroitin + Glucosamine: A Sulfur Cocktail for Hair and Nails

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Topical vs. Oral Antioxidants for Sun Protection – Which Is Better?

Eating the right foods can protect your skin from the sun. (Photo by Extra Medium)

While studies on antioxidants are generally pretty disappointing when it comes to life extension, they do have some use as anti-aging treatments for the skin.

While all or most antioxidants appear to protect from the harmful effects of the sun, some antioxidants are more effective than others. Carotenoids are a case in point. One example is lycopene, which is found in tomatoes. For example, one study showed that people who ate tomato paste daily had 33% more protection against sunburn compared to the control group.

Among carotenoids, lutein seems to give the best bang for the buck. In addition to photo-protection, lutein increases skin hydration and lipid levels while reducing lipid peroxidation.

But is it better to use antioxidants topically or orally? Some folks swear by their skin creams, while others maintain that eating the right foods is the best way to improve the skin. In the lutein study, the combination of taking a lutein supplement and using a lutein cream gave the best results. Not all that surprising – by using topical and oral treatments you're covering both grounds and playing it safe, after all.

However, a recent paper got me thinking whether "attacking the problem from all angles" is really the best way to go at it. The study looked at carotenoid levels in the skin after using carotenoids topically and systemically (link). 129 healthy women, aged between 21 and 72 years, were divided into seven different groups and given topical creams, oral supplements, both, or a placebo.

The first cream contained a basic mixture of antioxidants from sources such as vitamin E, vitamin C and green tea. The second cream contained the same antioxidant mix complemented by beta-carotene and lycopene. Similarly, the first supplement contained antioxidants from sources like green tea, green coffee, and pongamia pinnata seeds, while the second also contained carotenoids.

The placebo treatments did not increase carotenoid concentration in the skin, while the carotenoid cream increased it by 30% in the forehead and 35% in the cheek. That's not bad – until you look at the results in those subjects who used the tablets instead. Taking the antioxidant supplement containing carotenoids resulted in an 80% increase in the forehead and 70% in the cheek after just four weeks.

The interesting part is the group who used both the cream and the supplements. After four weeks, the results were similar to the group using only the supplement, with the supplement-only group actually scoring better in some areas. After eight weeks the group using both treatments saw the best results.

However, whereas the effect from using the cream lasted for only 10 days after stopping treatment, the results from taking the supplement were sustained for up to 5 weeks. The authors also point out that "surprisingly, the combined application of both tablets and creams containing carotenoids did not reach the satisfying result obtained with the application of tablets only".

The result is indeed unexpected, since using the antioxidant + carotenoid cream along with the antioxidant + carotenoid supplement did in fact yield the largest carotenoid concentration. However, using the antioxidant + no carotenoids cream together with the antioxidant + carotenoid supplement gave worse results than skipping the cream altogether. That is, using the cream somehow negated some of the benefits of the supplement.

According to the authors, it's possible that systemically applied antioxidants are absorbed and transported onto the skin surface with sweat and sebum and that applying a cream won't increase the concentration any further. This is because the strateum corneum, the outermost layer of the epidermis, acts as a reservoir for topically applied substances.

Hence, when you apply a skin cream, it penetrates into this layer and saturates the reservoir, which makes it impossible for systemically absorbed antioxidants to penetrate into the same layer through sweat and sebum. The authors state that compared to taking only an oral supplement, taking a supplement and applying a cream results in a lower carotenoid concentration.

To avoid this problem, the authors suggest that the formulation of the topical cream should be such that it does not saturate the reservoir and prevent the oral antioxidants from being transported into the skin. In effect, they advise against using lipid-rich formulations.

Many people seem to have seen good results in photo-protection from using oral supplements only. While combining it with topical creams may potentially give the optimal result, this study suggests that finding the right kind of product is important.

For more information on skin care, see these posts:

Tretinoin Results After a Year – Experiment Update
BioSil, JarroSil & Beer – Silicon Experiment Conclusion
Topical Vitamin C for Skin: Re-examining the Case
How to Get Natural Sun Protection by Eating the Right Foods

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