Resveratrol is a polyphenolic compound found in various berries (cranberry, blueberry, grapes) and herbs. Studies with trans-resveratrol have reported a diverse range of benefits in the areas of heart health, immunity and inflammation. Research has also revealed that trans-resveratrol mimics the biological longevity effects of a calorie-restricted diet.
Caloric Restriction (CR) is the only proven method of increasing life span in numerous and diverse species, from yeast, worms, fruit flies, spiders, rodents, all the way up to primates. Calorie restriction refers to an approximately 40% reduction in caloric intake, usually accompanied by a maintenance level of nutrients. The institutions that have conducted this research include Cornell and Harvard University, as well as the prestigious Massachusetts Institute of Technology (MIT) - testimony to the credibility behind Caloric Restriction. This research has branched out to encompass the study of 'caloric restriction mimetics'. These are compounds that enable organisms to parallel many of the beneficial biological effects of a caloric restriction diet, and among the most prominent of these is a substance known as resveratrol. Resveratrol is a naturally occurring polyphenolic compound found in various berries (cranberry, blueberry, grapes), peanuts, rhubarb and a number of oriental herbs including the Japanese Giant Knotweed (Polygunum cuspidatum).
Studies with resveratrol have reported a diverse range of physiological and biochemical effects, particularly in the areas of heart health, cancer, immunity and inflammation. Other beneficial cardiovascular effects include the reduction of cholesterol and triglycerides, dilation of blood vessels (hence a blood pressure lowering effect), platelets being less "sticky" (anti-aggregatory effect) - and consequently a lower incidence of atheroma or plaque formation and a reduced rate of strokes and heart attacks. Resveratrol exerts anti-oxidant effects by quenching free radicals that act as cellular terrorists, reducing the oxidation of LDL particles, which many believe to be the initiating event in atherosclerosis or hardening of the arteries. Resveratrol also inhibits unfavourable cellular proliferation and up-regulates apoptosis or programmed cell death.
The plants that produce resveratrol do so as a response to stressors such as fungal infection or ultra violet exposure. Resveratrol has been shown to enhance life extension much like caloric restriction in yeast (70%), worms (18%), fruit flies (30%), and fish (60%). The mechanism may be similar to sirtuin activation. There is considerable excitement regarding the use of resveratrol as a CR Mimetic. A recent study published in the prestigious journal Nature jointly by Harvard University and the National Institute of Aging demonstrated that resveratrol in high doses offset the effects of an unhealthy high-calorie diet in mice. Resveratrol is a molecule that occurs in nature in two forms or as mirror-images, namely the trans and cis forms. It is the trans version of the resveratrol that is the active form that has been used in all the investigations. The cis form may be at best inactive or at worst inhibit the activity of its mirror image - the trans form. There are high quality, naturally extracted sources that yield 98% plus trans activity.
With resveratrol supplementation, there are a number of challenges that need to be addressed if one is to achieve any therapeutic efficacy. Resveratrol has been shown to be very poorly bioavailable, readily undergoing metabolism via glucuronidation and sulphation. In order to increase resveratrol's bioavailability, one has to inhibit these enzyme systems by using specific substrates for these enzymes. It is possible to achieve this by using quercetin, piperine and luteolin, particularly the latter which has been shown to be the most potent inhibitor of sulphation. Resveratrol beadlets are relatively stable in oxygen, though the use of oxygen absorbers may help. The issue of oxygen sealed capsules seems to be a marketing ploy by various companies. The main stability issue seems to be centred on light and pH sensitivity. Formulations have to offer protection for these obstacles! Finally, there is a general consensus that high doses of resveratrol need to be used to achieve any clinically significant results. The latest animal studies suggest that the comparative human dose needs to be around 300mg (or more) per day for a 70 kg person.