A study of
Italians who consume a diet rich in resveratrol — the compound found in red
wine, dark chocolate and berries — finds they live no longer than and are just
as likely to develop cardiovascular disease or cancer as those who eat or drink
smaller amounts of the antioxidant.
"The
story of resveratrol turns out to be another case where you get a lot of hype
about health benefits that doesn't stand the test of time," says Richard
D. Semba, M.D., M.P.H., a professor of ophthalmology at the Johns Hopkins
University School of Medicine and leader of the study described May 12 in JAMA
Internal Medicine. "The thinking was that certain foods are good for you
because they contain resveratrol. We didn't find that at all."
Despite the
negative results, Semba says, studies have shown that consumption of red wine,
dark chocolate and berries does reduce inflammation in some people and still
appears to protect the heart. "It's just that the benefits, if they are
there, must come from other polyphenols or substances found in those
foodstuffs," he says. "These are complex foods, and all we really
know from our study is that the benefits are probably not due to
resveratrol."
The new
study did not include people taking resveratrol supplements, though few studies
thus far have found benefits associated with them.
Semba is
part of an international team of researchers that for 15 years has studied the
effects of aging in a group of people who live in the Chianti region of Italy.
For the current study, the researchers analyzed 24 hours of urine samples from
783 people over the age of 65 for metabolites of resveratrol. After accounting
for such factors as age and gender, the people with the highest concentration
of resveratrol metabolites were no less likely to have died of any cause than
those with no resveratrol found in their urine. The concentration of
resveratrol was not associated with inflammatory markers, cardiovascular
disease or cancer rates.
Semba and
his colleagues used advanced mass spectrometry to analyze the urine samples.
The study
participants make up a random group of people living in Tuscany where
supplement use is uncommon and consumption of red wine — a specialty of the
region — is the norm. The study participants were not on any prescribed diet.
Resveratrol
is also found in relatively large amounts in grapes, peanuts and certain
Asiatic plant roots. Excitement over its health benefits followed studies
documenting anti-inflammatory effects in lower organisms and increased lifespan
in mice fed a high-calorie diet rich in the compound.
The
so-called "French paradox," in which a low incidence of coronary
heart disease occurs in the presence of a high dietary intake of cholesterol
and saturated fat in France, has been attributed to the regular consumption of
resveratrol and other polyphenols found in red wine.
Background: The "French Paradox" of a low incidence of
coronary heart disease despite a diet high in cholesterol and saturated
fat in France has been attributed to the regular intake of red wine, in
particular, to resveratrol and other polyphenols contained in wine.
Some preliminary evidence also suggests that resveratrol may have
anti-inflammatory effects, prevent cancer, and decrease blood vessel
stiffness.
How the Study Was Conducted: The participants (a
sample of 783 men and women 65 years or older) were part of the Aging in
the Chianti Region study from 1998 to 2009 in two Italian villages. The
authors sought to determine if resveratrol levels achieved through diet
were associated with inflammation, cancer, cardiovascular disease, and
death. Levels were measured using 24 hour urine collections to look for
breakdown products of resveratrol.
Results: During nine years of follow-up, 268
participants (34.3 percent) died; of the 639 participants free of
cardiovascular disease at enrollment, 174 (27.2 percent) developed
cardiovascular disease during the follow-up; and of the 734 participants
who were free of cancer at enrollment, 34 (4.6 percent) developed
cancer during the follow-up. Urine resveratrol metabolite levels were
not associated with death, inflammation, cardiovascular disease or
cancer.
Discussion: "In conclusion, this prospective study of
nearly 800 older community-dwelling adults shows no association between
urinary resveratrol metabolites and longevity. This study suggests that dietary resveratrol from Western diets in
community-dwelling older adults does not have a substantial influence on
inflammation, cardiovascular disease, cancer, or longevity."
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