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European
Journal of Clinical Nutrition
6
Feb 2003
Red
Berries, Future Dietary Supplement?
Eating
red berries on a regular basis may help to protect
against the damage caused by free radicals,
according to new findings.
Red
berries, such as cranberries, blackberries and
black currants, contain a flavonoid called quercetin,
which has powerful anti-carcinogenic and enzyme-inhibiting
properties, researchers in Finland report in
this month's European Journal of Nutrition.
The team from the National Public Health Institute
in Helsinki, found that people with a high intake
of berries in their diet had higher levels of
the antioxidant quercetin in their blood, which
could boost protection against disease.
Elsewhere,
research is focusing on the colourants called
anthocyanins in red berries, blueberries and
blackcurrants, which are believed to have a
role in preventing heart disease.
For
this latest study, the researchers divided a
group of 40 men, aged 60 years old, into two
groups - one group continued their normal diet
for a period of eight weeks, while the other
ate a daily intake of 100 grams of berries,
including black currants, bilberries and lingonberries,
a berry variety consumed widely in Finland.
In Nordic countries berries constitute the most
important source of quercitin in the diet, with
quantities of up to 9.6 kilograms per capita
consumed each year in Finland.
Fasting
blood samples were obtained two weeks prior
to the study, at baseline, and at two, four
and eight weeks later. The intake of quercetin
was assessed from three day food records collected
at baseline and at eight weeks.
The
researchers report that concentrations of quercetin
in the blood were significantly higher in the
subjects consuming berries compared to the control
group. During the berry consumption period,
the mean serum concentrations of quercetin was
32-51 per cent higher in the berry group compared
with the control group.
The
authors noted that as the concentration of quercetin
found in each berry differs according to various
factors, such as the thickness of its skin,
the ripeness and growing conditions, the concentrations
would probably have been higher if fresh berries
had been used. However the scientists chose
to use frozen berries, as it was considered
to be more representative of general consumption
due the short yearly harvest period for berries.
The
authors concluded that the berries used in the
study are a good source of bioavailable quercetin.
They added that benefits of berries also include
low fat and calorie levels - music to the ears
for those preparing themselves for their summer
clothes.
Other
sources of quercetin include onions, tea, apples
and red wine.
The
study was supported by the Academy of Finland,
Juho Vainio Foundation and the Finnish Foundation
for Cardiovascular Research.
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Source: European Journal of Clinical Nutrition
(2003) 57; 37-42
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