Blueberry Skins Eyed as Cholesterol Busters
By Luis
Pons
March 26, 2007
Can blueberry skins be a key to controlling cholesterol? Perhaps,
according to Agricultural Research Service (ARS) study results announced Sunday at the
American Chemical Society's (ACS)
national meeting in Chicago.
ARS chemist
Agnes
Rimando and collaborators found that feeding hamsters a diet extremely high
in cholesterol, but supplemented with freeze-dried skins of rabbiteye
blueberries, produced plasma total cholesterol levels 37 percent lower than
those of hamsters fed a control diet.
Levels of LDL—or "bad"—cholesterol were 19 percent lower in
the blueberry-supplemented hamsters.
In addition, Rimando, in the
ARS
Natural Products Utilization Research Unit at Oxford, Miss., found that
hamsters eating the blueberry-enhanced food fared better than hamsters fed the
high-cholesterol diet augmented instead with the lipid-lowering drug
ciprofibrate. Animals in that group exhibited 17 percent less total
cholesterol—and two percent less LDL cholesterol—than the control
group.
The results may be linked to constituents in blueberry skins that can
activate a protein involved in the breakdown and import of fats, according to
Rimando. Among these constituents are resveratrol and pterostilbene, which have
been cited for their antioxidant properties.
Her main collaborator in the study was chemist
Wallace
H. Yokoyama of the
ARS
Processed Foods Research Unit in Albany, Calif. The researchers used 10
hamsters per treatment group, as well as a control diet containing the high
amounts of cholesterol, but no supplements.
Supplemented diets consisted of either 7.6 percent blueberry skins or
25 milligrams of ciprofibrate per kilogram of diet.
Rimando collaborated in another study, also described at Sunday's
meeting, which demonstrated pterostilbene's potential to fight colon cancer.
In that research, led by Rutgers
University scientist Bandaru S. Reddy, nine rats fed a diet supplemented
with 40 parts per million of pterostilbene showed 57 percent fewer induced
colon lesions than nine other rats fed an unsupplemented diet.
Source: ARS, U.S. Department of
Agriculture's chief scientific research agency.
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