A wide body of research, involving work with dozens of organisms spread all over the tree of life, has shown that restricting caloric intake tends to promote longevity. But it can also reduce energy levels and impair reproductive performance.
Scientists have shown that the plant secondary metabolite and antioxidant resveratrol mimics the impacts of caloric restriction and can prolong life (see the Antioxidants section for more on why this class of phytochemicals is so important).
An article published in the prestigious journal Nature reports that resveratrol can extend longevity by at least 10 percent and up to 60 percent in yeast, worms, and fly species (Jones et al., 2004). It does so by activating enzymes known as sirtuins, which play a key role in gene silencing, DNA repair, and the aging process.
Resveratrol is a polyphenol produced in plants in response to stress – quite possibly, as Jones et al. points out, stress stemming from a limited supply of plant nutrients (i.e., the way a plant experiences “caloric restriction”). Resveratrol levels are particularly high in certain species of red wine grapes.
Resveratrol in red wine is thought to play a role in explaining the “French Paradox” – the unexpectedly low rates of cardiovascular disease among people eating a Mediterranean diet high in saturated fat and calories, and often accompanied by red wine.
A French team (Levite et al., 2002) studied eight different wine grape varieties grown in six sites in western Switzerland. At each site, there was a vineyard growing a given variety using conventional methods right next to, or very close to another vineyard growing the same variety using organic farming practices. On average across the eight matched-pairs of conventional and organic vineyards, the organic grapes had 32 percent higher concentrations of resveratrol. That is a very significant difference, given the importance of increasing average, daily antioxidant intakes.
The Jones et al. paper provides further evidence that polyphenol plant secondary metabolites promote health through mechanisms in addition to their well-documented, anti-inflammatory effects.
Sources: “Sirtuin activators mimic caloric restriction and delay ageing in metazoans,” Jason Wood, Blanka Rogina, Siva Lavu, Konrad Howitz, Stephen Helfand, Marc Tatar, and David Sinclair, Nature, Volume 430, August 5, 2004
“Preliminary Results on Contents of Resveratrol in Wine of Organic and Conventional Vineyards,” D. Levite, M. Adrian, and L. Tamm, Proceedings 6th International Congress on Organic Viticulture, Edited by Helga Willer and Urs Meier, 2000.