Posted By: News-Medical in Men's Health NewsPublished: Thursday,
23-Sep-2004 

Four or more glasses of red wine per week may reduce risk of prostate
cancer by 50 percent

Drinking a glass of red wine a day may cut a man's risk of prostate
cancer in half, and the protective effect appears to be strongest
against the most aggressive forms of the disease, according to a new
study led by investigators at Fred Hutchinson Cancer Research Center.
The findings, by Janet L. Stanford, Ph.D., and colleagues in Fred
Hutchinson's Public Health Sciences Division, appear online in The
International Journal of Cancer.
"We found that men who consumed four or more glasses of red wine per
week reduced their risk of prostate cancer by 50 percent," Stanford
said. "Among men who consumed four or more 4-ounce glasses of red wine
per week, we saw about a 60 percent lower incidence of the more
aggressive types of prostate cancer," said Stanford, senior author of
the study. "The more clinically aggressive prostate cancer is where the
strongest reduction in risk was observed."
Stanford and colleagues found no significant effects – positive nor
negative – associated with the consumption of beer or hard liquor and
no consistent risk reduction with white wine, which suggests that there
must be a beneficial compound in red wine that other types of alcohol
lack. That compound, Stanford and colleagues believe, may be an
antioxidant called resveratrol, which is abundant in the skins of red
grapes but much less so in the skins of white grapes. The compound is
also found in peanuts and raspberries and is available as a dietary
supplement, which has been suggested to protect against cardiovascular
disease.
Laboratory studies indicate that resveratrol influences a variety of
biological pathways that are important in cancer development. For
example:
As an antioxidant, it helps sweep dangerous, cancer-causing free
radicals from the body.
As a potent anti-inflammatory agent, it blocks certain enzymes that
promote tumor development.
The compound also reduces cell proliferation, curtailing the number of
cell divisions that could lead to cancer or the continued growth of
cancer cells.
It also enhances apoptosis, or programmed cell death, which helps rid
the body of cancerous cells.
It may act as an estrogen, reducing levels of circulating male hormones
such as testosterone that fuel the growth of prostate cancer.
While the researchers found that the risk of prostate cancer decreased 6
percent for every glass of red wine consumed per week, Stanford is quick
to point out that research shows the law of diminishing returns comes
into play when consumption increases beyond moderation. "From a
public-health standpoint, it's difficult to recommend any alcohol
consumption given the risks associated with heavy consumption, from
increased overall cancer risk to accidental injury and social problems.
But for men who already are consuming alcohol, I think the results of
this study suggest that modest consumption of red wine – four to eight
4-ounce drinks per week – is the level at which you might receive
benefit. Clearly other studies show that more than that may have adverse
effects on health."
For the study, the researchers interviewed 753 newly diagnosed
Seattle-area prostate-cancer patients as well as 703 healthy controls
who served as a comparison group. Detailed information about tumor
aggressiveness (such as tumor grade and disease stage) was obtained
through the National Cancer Institute's Seattle-Puget Sound
Surveillance, Epidemiology and End Results cancer registry.
"Even though this study is based on relatively small numbers, the
results are very intriguing and suggest that the potential beneficial
effect of red wine and resveratrol – if indeed resveratrol is the
active chemopreventive agent involved – would be very important,
because it's the more aggressive forms of prostate cancer than are most
important to prevent," she said.
A particular strength of the study, Stanford said, is that the
participants were relatively young, ranging in age from 40 to 64, and
the majority were under 60.
"By focusing on men under age 65, whose incidence of prostate cancer is
much lower than that of older men, we can tease out the effect of a
particular environmental exposure on cancer risk, such as wine
consumption, more easily than if we were looking at men across the
entire age range," she said. This is particularly true when studying
complex diseases such as prostate cancer in which numerous genetic and
environmental factors are thought to play a role over an individual's
lifetime.
Another strength of the study is that in addition to being surveyed
about lifetime alcohol consumption, participants were asked about a
variety of other risk factors for prostate cancer, such as diet, family
history of cancer, screening for prostate cancer and tobacco use, all of
which were taken into account and adjusted for when analyzing the data.
While the majority of studies to date have assessed the effects of
overall alcohol use on prostate-cancer risk, fewer studies have
attempted to compare the effects of wine versus beer versus hard liquor,
and only one previous study has compared the impact of red versus white
wine on prostate-cancer risk, said Stanford, also a professor of
epidemiology at the University of Washington School of Public Health and
Community Medicine.
The previous study, the Netherlands Cohort Study, evaluated
prostate-cancer risk in relation to white and red wine consumption.
Increased risks were found in men who consumed "white and fortified
wines," but not red wine, as compared to nondrinkers, although there was
not a consistent trend in risks with levels of intake. Interestingly,
among men who consumed 15 or more grams of red wine per day (about one
and a half glasses per day), there was an overall 18 percent reduction
in risk and a 16 percent lower risk of advanced-stage prostate cancers.
The Netherlands Cohort Study was initiated in 1986 and collected
information by self-administered mailed questionnaires that asked about
alcohol consumption during the prior year only. Thus, the Netherlands
Cohort Study results only reflect associations with recent wine
consumption, as investigators were unable to examine lifetime intake as
was done in the current Fred Hutchinson study.
"One of the reasons we wanted to do this study is because overall, most
of the scientific literature – around 17 studies to date – haven't
shown a consistent relationship between alcohol consumption and prostate
cancer," Stanford said. "Some have shown an increase, some a decrease,
and most no association whatsoever. Part of the problem, we believe, is
that few of the studies have attempted to sort out the effects of
different types of alcohol intake over a man's lifetime."
Stanford and colleagues plan to seek funding to conduct a larger study
to see if their results hold up. In collaboration with Norm Greenberg,
Ph.D., of Fred Hutchinson's Clinical Research Division, they also plan
to test the effects of resveratrol on mouse models of prostate cancer to
see if giving mice this chemical compound will reduce the onset of
prostate cancer and/or decrease the aggressiveness of the disease.
The first author of the study, W. Marieke Schoonen, M.S., formerly a
graduate student in Stanford's group, is now a doctoral student at the
London School of Hygiene and Tropical Medicine. The National Cancer
Institute, National Institutes of Health and U.S. Department of Health
and Human Services funded the research.
http://www.fhcrc.org/

knowledge is power - growing old is mandatory - growing wise is optional    
"Many more men die with prostate cancer than of it. Growing old is
invariably fatal. Prostate cancer is only sometimes so."