Resveratrol is a stilbenoid polyphenol produced naturally by several plants in response to injury, fungal infection, or UV radiation — a class of compounds called phytoalexins. It is found in grapes (primarily in the skin), red wine, peanuts, Japanese knotweed (Polygonum cuspidatum, the main commercial source), and some berries. Resveratrol exists in two isomeric forms: trans-resveratrol and cis-resveratrol, with the trans form being the more stable and better-absorbed isomer, and the one present in commercial supplements.
The French paradox and how resveratrol was discovered
The "French paradox" refers to the epidemiological observation that French populations have relatively low rates of cardiovascular disease despite consuming diets high in saturated fat — an anomaly partly attributed to moderate red wine consumption. This observation prompted research into wine's bioactive components, leading to intensified study of resveratrol in the 1990s and 2000s. While the French paradox narrative drove public interest, the actual concentration of resveratrol in red wine is low (0.1–1.8 mg per glass), and drinking wine cannot replicate the doses used in research studies.
Sirtuins and longevity research
Resveratrol's most discussed mechanism involves SIRT1 — a member of the sirtuin family of NAD⁺-dependent deacetylase enzymes. Sirtuins regulate gene expression related to metabolism, DNA repair, and cellular ageing. In 2003, David Sinclair's laboratory at Harvard published a landmark paper showing resveratrol extended the lifespan of yeast by activating Sir2 (the yeast homolog of SIRT1). Subsequent studies showed lifespan extension in flies, worms, and fish. In mice fed a high-calorie diet, resveratrol improved metabolic parameters and extended lifespan.
Translation to humans has been more complicated. The direct activation of SIRT1 by resveratrol has been challenged — some researchers argue the effect is indirect, mediated through AMPK activation and PDE inhibition rather than direct SIRT1 binding. Clinical trials in humans have yielded mixed results, with benefits observed primarily in people with metabolic dysfunction.
Bioavailability problem
Resveratrol is rapidly metabolised — primarily sulphated and glucuronidated in the intestine and liver — meaning that very little free resveratrol reaches the bloodstream unchanged. Studies suggest peak plasma levels after oral resveratrol are low relative to doses consumed. This has driven interest in formulations designed to improve bioavailability, including micronised resveratrol, resveratrol with quercetin (which inhibits some metabolising enzymes), and phospholipid complexes.
Clinical evidence
Human trials have examined resveratrol for cardiovascular risk markers, insulin sensitivity, inflammation, and cognitive function. A meta-analysis of 21 trials published in 2018 found significant reductions in systolic blood pressure and improvements in glycaemic control in participants with metabolic dysfunction. Effects in healthy individuals are less pronounced. Doses in research range from 150 mg to 1,000 mg/day of trans-resveratrol.
Resveratrol in Lebanon
Supplements & More stocks trans-resveratrol supplements from US brands, available with cash on delivery across Lebanon.