SISYPHUS
PUBLICATIONS ONLINE
Resveratrol is a polyphenol type flavonoid currently exciting great interest as a potential boon to health. Like other flavonoids and polyphenols, it is a very useful anti-oxidant in its own right, but resveratrol has attracted particular attention as a potential solution to the so-called “French Paradox”.
This is the term used to describe the phenomenon, which has long been a puzzle to medical science, by which rates of cardiovascular disease in France have remained low relative to those in the rest of the developed world, despite the widespread national consumption of a diet high in animal fat and cholesterol, and a firmly entrenched tobacco habit. Of course France also enjoys many of the benefits of the so-called Mediterranean diet through its high intake of fresh fruit and vegetables, oily fish and olive oil, but there are good reasons to think that the consumption of red wine may be the real explanation of the apparent paradox.
It is known in any case that the moderate consumption of alcohol has a significant protective effect on the cardiovascular system, reducing disease by as much as 20-30%, but conventional medical opinion is characteristically cautious in acknowledging that the resveratrol in red wine may have any benefits over and above those which would in any case be provided by the alcohol. However, the role of fat-soluble anti-oxidants in protecting the circulatory system from damaging free radical attack is well understood, and it would therefore appear that the resveratrol and other polyphenols contained in red wine can only be beneficial. Laboratory tests, moreover, have shown resveratrol to have significant anti-coagulant and anti-inflammatory effects.
For the purposes of obtaining your
intake of resveratrol from wine you need to know that it’s
contained principally in the skins of red or black grapes, and is
consequently found in significant quantities only in those wines
produced by an initial pulp fermentation which allows the
developing alcohol to leach both colour and other substances,
including resveratrol, from the skins. It follows that the
longer this pulp fermentation is allowed to continue the more
resveratrol the wine will contain. So the colour of the
wine is a handy guide. Generally, the richer and darker the
colour of the wine the more resveratrol will be found. Rose
types and light reds may contain some, but white wines produced
by a juice fermentation alone will provide little if any.
Usually it is the red wines produced
in the sunnnier climates close to the Mediterranean, and the New
World, which will be richest in resveratrol, and dark red wines
of this type may provide as much as 2 mg of resveratrol in a
small 5 oz glass. But unfortunately from a health point of
view, these also tend to be the strongest in alcohol and the
so-called “congeners” which accentuate hangovers.
But fortunately for those who dislike
red wine, or are concerned about alcohol intake, other sources of
resveratrol are available. The amount in foods varies
widely, but the best sources are peanuts and red grapes, both of
which may provide anywhere between 0.3 and 1.3 mg of resveratrol
per cup. Bilberries and cranberries may also be a
useful source.
Supplements of resveratrol are also
now readily available, principally in the form of red wine or red
grape extracts, which will also contain other anti-oxidant
polyphenols. Manufacturers’ recommended doses will
typically provide between 10 and 50 mg of resveratrol, which
would require a very high, and potentially hazardous, level of
wine consumption to achieve regularly.
That said, there is no known toxicity
from taking resveratrol, as such, although its blood thinning
properties will tend to inhibit the blood’s clotting ability
and resveratrol is therefore not recommended for those taking
anti-coagulant drugs such as warfarin, or certain types of
anti-inflammatory including aspirin. Needless to say,
however, toxicity problems of a different kind may occur if
alcoholic drinks are used to excess as the principal or only
source.
But as noted above, moderate
consumption is generally recognised to be beneficial to health,
particularly for the cardiovascular system. So the
message seems to be: if you want to enjoy a couple of glasses of
wine with your dinner then go right ahead. And have that
age old pleasure enhanced by the knowledge that the resveratrol
it contains is also doing you some good.
Steve Smith
More About Anti-Oxidants, Liquid Vitamins And Minerals