The main active ingredient in cocoa is (-)-epicatechin. If you give the stuff to fat mice, they live longer. According to nutritionists at Virginia Tech, epicatechin [structural formula shown here] activates the enzyme AMPK.
Thanks to a mountain of research, much of which was funded by candy manufacturer Mars, cocoa has reached the status of superfood. Animal studies show that cocoa or epicatechin supplementation has the same effect on the body as physical exercise and enhances the positive effects of exercise. In addition, tests on fruit flies and rats suggest that epicatechin increases life expectancy.
Diabetes sufferers live eight years less than non-diabetics, but physical exercise reduces a number of the effects of diabetes. If epicatechin has approximately the same effect as physical exercise, might epicatechin be able to extend the life expectancy of diabetics? Nutritionists at Virginia Tech attempt to answer this question in an animal study, published in the Journal of Nutrition.
The researchers added epicatechin to the drinking water of overweight, diabetic mice [db] for 15 weeks. The concentration was 0.25 percent. This meant the mice got about the equivalent amount of epicatechin [EC] as humans who consume 8-32 g cocoa per day. [Note for adventurous ergonauts: cocoa is only one ingredient in chocolate.]
The figure below on the right shows that after week 6 the diabetic mice started to die. But the diabetic mice that were given epicatechin [db+EC] lived almost as long as the healthy mice [Control]. The figure below on the left shows that epicatechin supplementation boosted the concentration of active AMPK. The figure here shows the effect on muscle cells, but the researchers saw the same effect on liver cells.
The table above shows the positive effects of epicatechin supplementation: the concentration of protective SOD increases; that of 'bad cholesterol' LDL, inflammatory factors Interleukine 1b and CRP decreases; and the amount of IGF-1 in the blood decreases. The latter effect may explain why epicatechin appears to have a life-extending effect.
Diabetics have high levels of IGF-1 in their blood, but that IGF-1 doesn't help muscle build up. It's more likely to stimulate tumour growth in diabetics.
The researchers suggest that epicatechin may inhibit the production of IGF-1 via AMPK. We wonder whether epicatechin doesn't help IGF-1 to attach itself to receptors in muscle cells, and that this leads to a reduction of IGF-1 levels.
"The findings in this study demonstrate that epicatechin may be an antiaging compound, as evidenced by the improved db/db mouse survival and the favorable changes in a variety of age-related biomarkers", the researchers summarise. "However, more preclinical studies are needed to further characterize the potential antiaging effects of this compound and to define the exact molecular mechanisms by which it may act."
J Nutr. 2011 Jun;141(6):1095-100.