SEATTLE, May 9 /PRNewswire-USNewswire/ -- The risk of the two major prostate diseases, cancer and benign prostatic hyperplasia (BPH), can be reduced by changes in lifestyle, such as avoiding smoking, maintaining a normal weight and eating a healthy diet. Alan Kristal, Dr.P.H., associate head of the Cancer Prevention Program at Fred Hutchinson Cancer Research Center in Seattle, has conducted many studies that suggest men need not feel helpless against prostate cancer or BPH.
For example, Kristal and colleagues have found that: -- Eating cruciferous vegetables, especially broccoli, at least three
times a week may reduce a man's risk of prostate cancer by nearly
half. Scientists believe that these vegetables protect against cancer
because they contain isothiocianates, which increase the activity of
enzymes that can both detoxify cancer-promoting compounds and decrease
the concentration of active androgens (steroid hormones) in the
prostate.
-- Dietary supplementation with selenium and vitamin E may significantly
reduce the risk of prostate cancer. Kristal and colleagues found that
men who take a daily vitamin E supplement lower their risk of
aggressive prostate cancer by nearly half. Kristal and colleagues are
now engaged in a clinical trial with more than 35,000 men testing
whether selenium and/or vitamin E can prevent prostate cancer.
-- Men who eat a diet low in fat and red meat, moderate in alcohol, and
high in vegetables and lean protein have a significantly lower risk of
developing symptomatic benign prostatic hyperplasia, or BPH, a
condition associated with frequent and painful urination that affects
nearly all men by age 70. Kristal and colleague found that a high-fat
diet increased the risk of BPH by 31 percent, and that daily
consumption of red meat increased the risk by 38 percent. The
researchers also found that eating four or more servings of vegetables
daily was associated with a 32 percent reduction in risk, consuming
high amounts of lean protein was associated with a 15 percent risk
reduction, and that regular, moderate alcohol consumption (no more
than two drinks a day) was associated with a 38 percent decline in BPH
risk.
-- Obesity is associated with an 80 percent increase in the risk of
high-grade, aggressive prostate cancer. What's more, in men who are at
high risk of prostate cancer because of prostate cancer occurring in a
first-degree relative, the distribution of body fat may also
contribute to increased prostate-cancer risk. "Apple-shaped" men, who
store fat in the abdominal area, have a nearly two-fold increased risk
of both low- and high-grade prostate cancer. The mechanisms behind the
link between obesity and the most aggressive, fatal form of prostate
cancer are believed to involve both steroid hormones and systemic
inflammation. "Obesity is a massive inflammatory condition," Kristal
said. "It also increases levels of circulating estrogens and growth
factors that promote cell growth." -- A high-calcium diet, calcium supplements and antacids may increase the
risk of advanced prostate cancer. In men who consume more than 1,200
mg per day (equivalent to four or more glasses of milk), the risk of
aggressive cancer increases by more than 100 percent. High intake of
calcium suppresses blood levels of the active form of vitamin D, a
hormone that may protect against prostate cancer.
-- Obese men who are diagnosed with prostate cancer have more than
two-and-a-half times the risk of dying from the disease as compared to
men of normal weight at the time of diagnosis. "If a man is obese at
the time of diagnosis, he faces a 2.6-times greater risk of dying as
compared to a normal-weight man with the same diagnostic profile,
regardless of whether he has a radical prostatectomy or radiation
therapy, whether or not he gets androgen-deprivation therapy, whether
he has low- or high-grade disease or whether he has localized,
regional or distant disease," Kristal said.
-- Heavy smokers who are diagnosed with prostate cancer have twice the
risk of dying from their disease. Smoking may promote prostate cancer
growth through several mechanisms. One is that it can increase the
amount of circulating androgens, which fuels the growth of malignant
prostate cells. Another theory is related to tobacco as a source of
cadmium, a heavy metal that has been linked to prostate cancer in
several occupational-health studies. This known human carcinogen
inhibits DNA repair, which allows cancer cells to mutate and multiply.
-- African-American men are known to have a higher risk of prostate
cancer than white men. Kristal and colleagues also found that
African-American men have a 50 percent higher risk of developing
symptomatic BPH than white men.
-- The excitement about lycopene (the pigment that puts the red in
tomatoes) and prostate-cancer prevention is probably a mistake,
Kristal says. Most large and well-designed human studies, and most
animal studies, have failed to find convincing associations between
lycopene and reduced prostate-cancer risk. Men should be wary of quick
fixes like lycopene supplements, vegetable-juice powders or other
agents promoted for prostate-cancer prevention.
The take-away message from all of these studies is that men can lower their risk of prostate disease by making lifestyle changes. Achieving and maintaining a healthy weight, eating a diet low in fat and high in a variety of vegetables (especially broccoli), and achieving and maintaining a normal body weight can lower the risk of developing BPH and prostate cancer. And if a man is diagnosed with prostate cancer, quitting smoking and losing weight may lower the risk of developing an aggressive, lethal form of the disease.
This news release was issued on behalf of Newswise(TM). For more information, visit http://www.newswise.com/. DATASOURCE: Fred Hutchinson Cancer Research Center CONTACT: Kristen Woodward of Fred Hutchinson Cancer Research Center, +1-206-667-5095, Web Site: http://www.fhcrc.org/
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