Resveratrol, it seems, just can’t seem to catch its breath.  Whether the focus of still another research study on its potential health benefits (see archived articles: Wine and Inflammation, Radioprotective Effects of Wine, Alcohol Impact on Alzheimer’s in the Elderly, Wine Consumption in Males May Extend Life, Grape Seed Extracts May Suppress Leukemic Cells, Study Finds Heightened Risk of Breast Cancer With Wine, Resveratrol May Counteract Obesity and Resveratrol May Limit Damage Post Stroke) or advertised as a “cure all for what ails ya,” word of the compound seems to be everywhere.  So what is resveratrol?

Resveratrol is what is known as a polyphenol found in, amongst other things, the skin of red grapes.  Phenolic compounds, a type of antioxidant, are divided into flavinoids (those compounds that are responsible for the flavor and taste of grapes and other fruits such as tannins) and non flavinoids, of which resveratrol is a member.  Resveratrol is also found in peanuts, mulberries, blueberries, cranberries, spruce, eucalyptus and various Chinese herbs.  Now that I have bored you with some very basic chemistry, lets get into the facts. 

Resveratrol has been demonstrated to exert both antioxidant and anti-inflammatory action.  (An antioxidant is capable of slowing or preventing the oxidation of other molecules.  Oxidation produces what is known as free radicals, atoms or molecules that have an unpaired electron in its outer shell.  These unpaired electrons tend to be highly reactive and can trigger brisk and sometimes deadly reactions at the cellular level).  It reduces the oxidation of the low density lipoproteins or LDL and inhibits the aggregation of platelets, thus reducing the risk of clotting and thrombosis and possible coronary heart disease.  Anti-inflammatory effects seems to be expressed through the inhibition of activity of a particular enzyme as well as the release of another cellular substance.

Both cell cultures and animal studies have hinted that resveratrol can inhibit the proliferation of some cancer cells through a process called apoptosis and anti-estrogenic effects.  Simultaneously, there are opposing studies that indicate that the compound could have estrogenic effects.  It is this controversy that clouds the risk issue of consuming resveratrol based food and beverages, such as wine, in women with a history or risk of breast cancer.  Studies have noted that resveratrol can inactivate some enzymes in certain types of tumor cells while also playing a role in the efficacy of cancer chemoprevention.  Cellular and animal studies have demonstrated inhibitory effects on squamous cell carcinoma, promyelocytic leukemic cells and neuroblastoma cells secondary to apoptosis.  There have also been studies at the cellular level that implicate resveratrol in extending life span through the activation of a set of genes called sirtuins.  Sirtuins are a family of enzymes that regulate some of the activity of the cell nucleus.  Interestingly enough, caloric restrictions in some animal studies have extended life span by 50%, perhaps mimicking the effects of sirtuins.  Resveratrol has also recently sparked interest as a possible therapy in certain categories of diabetes and has been studied in obesity. 

It’s extremely important to emphasize that many of the studies conducted to date are either in vitro or in animals.  The studies preformed in human subjects, while often suggestive of benefits, offer an association between resveratrol and improved health and not conclusive evidence.  As well, conflicting evidence regarding high versus lower cellular concentrations of resveratrol need to be further addressed.  It appears as if lower cellular concentrations are more associated with cellular survival mechanisms while much higher doses seem to activate apoptosis and cell death.  This may explain why lower doses factor into the mitigation of age related disease states such as cardiovascular and neurodegenerative ailments while higher concentrations may be more effective in targeting certain cancers.  All that being said, resveratrol should not be viewed as some panacea nor fountain of youth.

First of all, resveratrol when administered orally is largely inactivated by the gut and liver.  Once metabolized, more than 50% of the ingested compound or its metabolites are excreted in the urine.  That does not minimize the possible benefits in vivo of the absorbed compound.  In true physiological terms, it simply translates into only a fraction of the substance finding its way into your body at the cellular level.  Second, there are a few side effects to consider if you are entertaining or taking resveratrol.  Most importantly, resveratrol seems to exhibit some estrogen like properties which, in turn, may lead to cancer cell proliferation in those stimulated by estrogen.   While there have been conflicting studies on the risk versus benefits of wine consumption in women with a history of breast cancer, it seems best to minimize or avoid consumption until the issue is firmly resolved.  And as always, if you are considering wine consumption, please consult with your physician. 

So why not simply drink enough red wine to attain the necessary concentration of resveratrol?  Unfortunately, you would have to consume tens, perhaps hundreds of bottles per day…..enough said on that one!!

As you might expect, the market for resveratrol in the form of supplements has been vigorous, with many companies offering potential claims of unheralded health benefits and at pricey levels.  You should understand right up front that, as of this date, there has been no landmark study that offers proof of the benefits of ingesting resveratrol.  As well, the substance is not regulated by the FDA (although unsubstantiated claims might trigger some interest), opening up a Pandora’s Box of uncertainties such as chemical structure and concentration of the substance in the supplement.

Clearly, many of the in vivo studies hint at an association between consumption of red (and white) wine as well as alternative forms of alcohol and health benefits.  And clearly the results are encouraging in vitro and in animal studies.  But it’s likely that many years, perhaps decades, of research will be necessary before we know conclusively if and how resveratrol is translated into human benefits.  In the meanwhile, I’ll have to be content with my latest glass of two of wine du jour with dinner.

Tags: antioxidant, flavinoid, health benefits, nonflaviniod, oxidation, polyphenol, Resveratrol, tannins