Blueberries, Wine, and Antioxidants
In the last few years, blueberries have been touted
as containing anthocyanidins, substances that
reverse or postpone aging. However, despite the
presence of these and other antioxidants in
blueberries, the one study (published in 2002)
evaluating absorption of these chemicals into
humans demonstrated poor absorption. Also, the
studies showing anti-aging and anti tumor benefits
were done on cell cultures and rats, not humans,
with doses much more concentrated than possible
from whole fruit. Similarly, preliminary evidence
suggests blueberries can prevent bacterial
adhesion to the bladder and bacterial colonization
(as do cranberries); however, this evidence is
insufficient to allow recommendation for this use,
either. So enjoy eating our delicious blueberries as
a part of a balanced diet, but don’t expect
miracles!
Similarly, red wine has been marketed as a source
of resveratrol, another antioxidant. Red wine is the
best dietary source of resveratrol, in greatly varying
amounts; this antioxidant is found in smaller
amounts in blueberries. Significant research has
been done in cell culture and animal models with
“free” (unconjugated) resveratrol, showing
reduced aging and incidence of cancer. However,
humans can’t absorb enough of this compound
from wine to be significant. At this time, there is no evidence that resveratrol supplements actually
have any health benefit in humans; doses would likely need to be a thousand times that found naturally.
Consumption of small amounts of alcohol of any sort does decrease the risk of coronary heart disease,
atherosclerosis (hardening of the arteries), and heart attack when compared with nondrinkers. This
benefit is seen in women at one drink a day, and men at 2 drinks a day; more is NOT helpful. 3 (women)
or 4 (men)drinks a day or more can cause heart, liver, memory, depression and anxiety problems, as
well as a greater risk of problem drinking and violence. (One drink is 12 oz of beer, 5 oz wine, or 1.5 oz
80-proof distilled spirits.) The same (one or two drinks a day) or lighter consumption of alcohol may
reduce the overall risk of mortality from any cause. However, any alcohol intake increases the risk for
breast cancer; the effect is uncertain on other cancers until over 4 drinks, which is a risk factor for most
cancers. The actual benefits of alcohol are difficult to measure, as there are many confounding
variables.
Thus, if you have no health consideration, and are so inclined, one drink a day for women, two for men,
three to four days a week may be beneficial to your health. (Saving them up to drink at one time, even
occasionally, is called binge drinking, and is not healthy.) Supplements of these antioxidants have no
proven efficacy.
References:
Natural Medicines Database, accessed 23 August, 2011
UpToDate, accessed 23 August, 2011