It all started with the work of Dr Roy Walford back in the 1980’s who discovered extraordinary longevity benefits in animals by eating ‘optimum nutrition’ but with restricted calories. Now we know that the process of eating much less in a day is one of the factors (two others being exercise and resveratrol) that switches on the SIRT1 gene nicknamed the ‘skinny gene’. As Jerome Burne writes ‘It improves protection from free radical damage and repair of DNA damage, cuts down inflammation and makes mitochondria, the tiny power plants in each of our cells work more efficiently’.
Think of it from an evolutionary point of view. We are hunter gatherers and not all days are successful as others, so having modified fast days and feast days makes sense. It may also be easier than trying to eat less every day. Of course, part of the gold of low GL diet is you don’t feel hungry anyway, but you could do this along with intermittent dieting by pushing it one day, and allowing yourself to be on the edge of hunger, and then being more lenient the next. You only need a 20% drop in calories to trigger the SIRT1 effect so this could equate to 50 GLs one day, then 40 the next, especially if you make your 40 GL day low fat.
The other trigger is exercise. The more you do the more this gene kicks in.
Then there’s the very interesting research on resveratrol, which I take every day in an antioxidant formula. (Resveratrol is found in green vegetables, mulberries, citrus fruit and the skins of peanuts, but is most abundant in red grapes and good quality red wines. A good bottle of merlot, for example, can provide 20mg, whereas cheap wines often have as little as 2mg.) Researchers at Harvard Medical School have shown that resveratrol activates the SIRT1 gene in yeast thus extending life span by more than 50 per cent!
Not only does a concentrate of resveratrol switch on the survival gene but it also favourably affects over a hundred genes that help programme you for longevity. Dr John Pezzutto of the University of Illinois, describes resveratrol as ‘a whiff that induces a biologically specific tsunami’, referring to its wide range of positive effects on gene expression away from disease and towards health and youth. Resveratrol may even help you lose weight. Firstly, it inhibits fatty acid synthase, an enzyme needed to convert sugars into fat, and reduces insulin levels, which means less blood sugar lows and less hunger. Resveratrol is currently being tested in clinical trials for diabetes.
The combination of a low GL diet, eating less every other day, supplementing 25mg of resveratrol a day, and exercising is probably a winning formula for losing weight and living longer.