Resveratrol, a compound found in grapes,
red wine and peanuts, can improve blood
flow in the brain by 30 per cent, thereby
reducing the risk of stroke, according to
the results of a rat study.
Researchers at the National Taiwan Normal
University and the National Chia-Yi
University report that rats with induced
reduction of blood flow (ischemia) in the
brain experienced an improved blood flow
from a single dose of resveratrol.
“We found that resveratrol
administration… led to cerebral blood flow
elevation and protected animals from
ischemia-induced neuron loss,” said
lead author Kwok Tung Lu.
Strokes occur when blood clots or an
artery bursts in the brain and interrupts
the blood supply to a part of the brain.
It is the leading cause of disability and
the third leading cause of death in Europe
and the US. According to the Stroke
Alliance for Europe (SAFE), about 575,000
deaths are stroke related in Europe every
year. In the US, every 45 seconds someone
will experience a stroke, according to the
American Stroke Association.
The new study, published in the
Journal of Agricultural and Food Chemistry
(Vol. 54, pp. 3126-3131), divided 60 adult
male Wistar rats into three equal groups.
The first group was the control. The
second group underwent the induction of
cerebral ischemia, and the third group
underwent the same operation but also
received an intravenous dose of
resveratrol (20 milligrams per kilogram
Although no change to mean blood
pressure or heart rate was observed,
cerebral blood flow in the second group
decreased by 65 per cent compared to the
control group. The ischemia plus
resveratrol group’s blood flow also
decreased, but by only 35 per cent.
The researchers also found that the
concentration of nitric oxide (NO) in the
affected part of the brain was 25 per cent
higher than for both the control and
ischemia-only group. NO is a molecule used
by lining of blood vessels (endothelium)
to signal to the surrounding muscle to
relax – this dilates the blood vessel and
increases the blood flow.
“We suggested that resveratrol may
elicit neuroprotective effects by
stimulating NO formation or release, which
increases cerebral blood flow,” said
The authors said that further
investigation of the effects of
resveratrol was needed. Of particular
interest is the dose needed to produce
protection While resveratrol has been the
subject of various studies, particularly
in relation to heart health, recent
studies have reported brain protecting
effects from grape juice or wine – an
effect linked to a synergy between the
various polyphenols present.
A recent study using Concord grape
juice by researchers from Tuft’s
University reported that the combination
of the polyphenols could decrease the
effects of aging on the brain.
“It may be that the whole is greater
than the sum of its parts,” lead
author Barbara Shukitt-Hale wrote in the
journal Nutrition (Vol. 22, pp.
The amount of resveratrol in a bottle
of red wine can vary between types of
grapes and growing seasons. But nearly all
dark red wines – merlot, cabernet,
zinfandel, shiraz and pinot noir – contain
The health implications of red wine
consumption appear to be filtering through
to the consumer. A report from analysts
Euromonitor in 2004 predicted that still
red wine will exhibit by far the fastest
growth in both volume and value terms
between 2002 and 2007.
Their study claims that red wine is
forecast to record global value sales of
$82bn (€61.5bn) in 2007, a rise of some 31
per cent from 2002.
However, experts are quick to warn that
moderation is the key. A study from
Harvard University last year reported that
people who have three or more alcoholic
drinks per day have a significantly higher
risk of stroke. Lowest risk was observed
for those who had one, or maybe two,
drinks every other day.