Chocolate can extend lifespan and improve cognitive performance, in rats, anyway, and there’s little reason to doubt that it would in humans. In the following study, the researchers used a special form of cocoa powder, Acticoa, which has been processed in such a way as to preserve a high content of flavanols. Acticoa is made in Switzerland and as far as I can see is not available in the U.S. Effects of long-term administration of a cocoa polyphenolic extract (Acticoa powder) on cognitive performances in aged rats.
Numerous studies have indicated that increased vulnerability to oxidative stress may be the main factor involved in functional declines during normal and pathological ageing, and that antioxidant agents, such as polyphenols, may improve or prevent these deficits. We examined whether 1-year administration of a cocoa polyphenolic extract (Acticoa powder), orally delivered at the dose of 24 mg/kg per d between 15 and 27 months of age, affects the onset of age-related cognitive deficits, urinary free dopamine levels and lifespan in old Wistar-Unilever rats. Acticoa powder improved cognitive performances in light extinction and water maze paradigms, increased lifespan and preserved high urinary free dopamine levels. These results suggest that Acticoa powder may be beneficial in retarding age-related brain impairments, including cognitive deficits in normal ageing and perhaps neurodegenerative diseases. Further studies are required to elucidate the mechanisms of cocoa polyphenols in neuroprotection and to explore their effects in man.
The rats fed cocoa lived 11% longer than controls, which I would say is a huge increase in lifespan from the mere addition of cocoa to their food.
The rats received 24 mg/kg of body weight. To convert to a human dose, multiply by 6/37 (see here), which comes to about 4 mg/kg. So, for a 75 kg (165 lb) man, the daily dose of cocoa would be about 300 mg. Keep in mind that this was a concentrated form of cocoa (Acticoa). According to their website, Acticoa has 5 or more times the amount of flavanols than regular cocoa powder, so adjust accordingly.
Another study found that the mere addition of epicatechin, one of the major flavonoids in cocoa, to the diets of diabetic mice, radically reduced the death rates from 50% in controls, to 8% in the epicatechin group. Dietary epicatechin promotes survival of obese diabetic mice and Drosophila melanogaster. What this tells me is that a hormetic response can protect against diabetes. There’s good evidence that lack of hormesis contributes to diabetes: Resistance to type 2 diabetes mellitus: a matter of hormesis?
Despite the fact that even people who should know better refer to substances like epicatechin as antioxidants, in reality they are not. They work via hormesis, that is, by providing low doses of toxins to which the body mounts an anti-stress response. In the case of diabetes above, the flavonoids acted as hormetic agents and thus prevented diabetic mice from dying. That’s my interpretation.
Also, cocoa has far more flavonoids, 2 to 4 times more, than tea or red wine. I have to remind myself to eat more chocolate.