Thursday, May 26, 2011

Green Tea Polyphenol Heals Stomach Ulcers

Green Tea Polyphenol Heals Stomach Ulcers
Green tea is a good candidate for treating stomach ulcers. (Photo by toughkidcst)

Non-steroidal anti-inflammatory drugs (NSAID) are generally used for treating pain and reducing fever. The most common NSAIDs are aspirin and ibuprofen. While effective, these drugs have some pretty nasty side effects. For example, up to one in four regular users develop a chronic gastric ulcer at some point.

In addition to causing gastric, peptic and duodenal ulcers, NSAIDs also delay ulcer healing. In the United States, upper gastrointestinal problems from non-steroidal anti-inflammatory drug use result in 16,500 deaths every year. What's worse, almost half of the prescriptions for NSAIDs are estimated to be unnecessary. Anti-ulcer drugs, on the other hand, are expensive and do not prevent the ulcers from recurring.

In a recent Indian study, the effectiveness of the anti-ulcer drug omeprazole and one of green tea's polyphenols, epigallocatechin gallate (EGCG), was compared in mice (link). The mice were first given enough of a NSAID called indomethacin to cause stomach ulceration. After that they were split into three groups: the first group was given a standard effective dose of omeprazole (3 mg/kg), while the second group was given EGCG in various doses (0.5–5 mg/kg). The third group acted as the control group and was given no treatment.

After three days, the ulcers of the mice in the control group had not healed at all. The omeprazole-treated mice had healed ~75% of their stomach ulcers. The effectiveness of the green tea polyphenol was dose-dependent: with 3 mg/kg, the ulcers healed as effectively as with omeprazole, while the largest dose (5 mg/kg) resulted in ~82% healing.

Non-steroidal anti-inflammatory drugs cause gastric ulcers through a variety of mechanisms. They increase the production of reactive oxygen species (ROS), increase lipid peroxidation and cause an imbalance in cytokines which regulate the immune system. In this study, EGCG improved all three factors even more effectively than omeprazole.

Although both omeprazole and epigallocatechin gallate have antioxidant properties, the mechanisms through which they work differ from each other. The main reason omeprazole works is because it reduces the production of gastric acid, whereas green tea is said to increase gastric acid release. While more studies are probably needed, the authors of the paper consider EGCG a promising candidate for treating stomach ulcers because it has not been shown to have negative side effects even with large doses (although there are potential problems with high-dose green tea extracts).

For more information on green tea, see these posts:

Green Tea Protects from the Psychological Effects of Stress in Rats
Tea, Coffee and Cocoa: All Good for Your Teeth
Green Tea and Capsaicin Reduce Hunger and Calorie Intake
Green Tea Extract Increases Insulin Sensitivity & Fat Burning during Exercise

Read More......

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Wednesday, May 11, 2011

Lithium in Drinking Water May Lead to Longer Life

Water may have an effect on your longevity.
Water may have an effect on your longevity. (Photo by anthony_goto)

Lithium is an essential trace element found mostly in drinking water and vegetables. However, nutritional intake of lithium varies considerably, depending on where you live.

In rats, a deficiency of lithium causes health problems such as behavioral abnormalities, but in humans, lithium deficiency is an unknown concept. On the other hand, there have been studies suggesting that  lithium intake, even at low doses, is inversely correlated with suicide risk. High-dose lithium has been used for decades to treat psychiatric conditions such as bipolar disorder.

Lithium may also have other life-extending properties besides reducing suicide risk. For example, roundworms have been shown to live up to 36% longer when given lithium chloride, but the amounts used are 1000-fold higher than would be obtainable through diet. Such a high dose may not be necessary, however. In a recent paper roundworms were shown to live longer when given a low concentration of lithium chloride throughout their life – with the effect being less pronounced than with high doses (link).

The authors also looked at lithium in drinking water and total mortality in 18 neighboring Japanese municipalities. They found that tap water levels of lithium were inversely associated with overall mortality adjusted for age and gender. Since lithium levels have been associated with lower suicide rates, the authors also adjusted for suicide. The inverse association between lithium and overall mortality remained.

Lithium concentrations in drinking water ranged from 0.7 to 59 mcg/L. The highest value equals a concentration of 8.5 micromoles. A lithium concentration of 10 micromoles was enough to extend the lifespan of roundworms, while a concetration of 1 micromole was not.

The inverse association between mortality and lithium in drinking water obviously does not prove that lithium reduces mortality in humans, but the roundworm experiments show that the idea is not so far-fetched. Although the mechanism is still unknown, I wonder if the mental health aspect has something to do with it.

Too bad there doesn't appear to be any lithium in the tap water where I live, or at least they don't report it. It is also available as a supplement, but some countries may have customs restrictions on some or all forms lithium.

For more information on longevity, see these posts:

High HDL Cholesterol Reduces Risk of Dying in Men
Selegiline and Lifespan Extension
Does Intermittent Fasting Increase Lifespan?
The 7 Types of Aging Damage That End up Killing You

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Thursday, May 5, 2011

Drinking Coffee = Higher Adiponectin = Lower Body Fat Percentage?

Drinking coffee increases adiponectin levels
Want to lower your body fat? Coffee might an option. (Photo by annais)

Adiponectin is a protein hormone that modulates several metabolic processes related to weight gain. Adiponectin levels are inversely correlated with body fat percentage (link) – for example, diabetics have lower levels of adiponectin than non-diabetics, and losing weight increases adiponectin levels.

Since adiponectin affects glucose uptake and insulin sensitivity, and low adiponectin levels are a risk factor for developing diabetes and metabolic syndrome, it raises the question of whether increasing adiponectin levels might be a good thing.

A study from last year looked at the effects of coffee on adiponectin levels in 665 Japanese males (link). Adiponectin levels were measured from serum samples, and coffee consumption was assessed using a self-administered questionnaire. The questionnaire also included green tea consumption, so that the effects of green tea and coffee could be compared.

The participants who drank more coffee tended to be younger, more likely to smoke, and less likely to drink alcohol. The mean age of non-drinkers was 49.9, while the mean age of those who drank at least three cups per day was 48.2. Interestingly, non-drinkers had the highest mean blood pressure (systolic 129.5 and diastolic 80.7 mmHg) of all groups, while those who drank 1-2 cups per day had the lowest (123.1 and 76.7) – although this could just be due to the age difference. There were no significant differences in BMI or physical activity between coffee drinkers and non-drinkers. Unfortunately, body fat percentage was not measured.

However, adiponectin levels were significantly higher in those who drank coffee compared to non-drinkers. In those who drank none, 1–5 cups per week, 1–2 cups per day, and >2 cups per day, adiponectin levels were 5.95, 6.51, 7.05 and 6.89 mcg/mL, respectively.

When confounding factors such as age, smoking status and BMI were adjusted for, adiponectin levels were still positively associated with coffee consumption. There was a significant dose-response relationship between coffee consumption and adiponectin levels. However, there were no significant differences in adiponectin levels between those who drank 1–2 cups and those who drank >2 cups per day.

Green tea was not associated with adiponectin levels. There was also no association between coffee consumption and total cholesterol, HDL or LDL.

Although this study included only men, similar findings have been reported in women. In one study, diabetic and non-diabetic women who drank at least four cups of coffee per day had higher adiponectin levels than those who didn't drink coffee regularly (link). Interestingly, caffeine consumption was also associated with adiponectin levels. Perhaps the adiponectin-increasing effect of caffeine is diminished or blocked by other compounds such as L-theanine in green tea.

There's also one interventional study on habitual coffee drinkers that found coffee consumption increased adiponectin levels (link). Unlike in the study on Japanese males, total cholesterol and HDL also increased – possibly because the intake of coffee was higher (8 cups per day) at the end of the experiment.

Based on this and other studies, the key points are:

a) those who drink coffee have higher adiponectin levels than those who don't
b) those who have higher adiponectin levels have lower body fat percentage

All in all, while correlation does not prove causation, it seems plausible that drinking coffee could help maintain a lower body fat percentage and avoid type II diabetes and metabolic syndrome.

If you have personal experiences with coffee and weight loss, feel free to share them in the comment section below. For more information on weight and fat loss, see these posts:

Why Are Thin People Not Fat?
A Year of Intermittent Fasting: ADF, Condensed Eating Window, Weight Loss, And More
Green Tea and Capsaicin Reduce Hunger and Calorie Intake
The Twinkie Diet: Thoughts on Weight Loss and Cholesterol

Read More......

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