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
-- 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
-- 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.
|SOURCE Fred Hutchinson Cancer Research Center|
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