Prostate Cancer Prevention
One of the ways of preventing Prostate cancer is understanding the risk
factors and making changes in your life style to lesson your chance of developing Prostate
Cancer. Beyond that there are supplements you can take and things you can add to your
diet.
Prostate Cancer Prevention - Avoiding Risk Factors
Diet - Men who eat a lot of red meat or who have a lot of high-fat dairy
products in their diet appear to have a greater chance of developing prostate cancer.
These men also tend to eat fewer fruits and vegetables. Doctors are not sure which of
these factors is responsible for increasing risk.
Some studies have suggested that men who have very high consumption of calcium (through
diets or supplements) may have a higher risk of developing advanced prostate cancer. Most
studies, however, have not found such a link with the levels of calcium commonly consumed
in the average diet, and calcium is known to have other important health benefits.
Several substances, including lycopenes (found in high levels in some fruits and
vegetables, such as tomatoes, pink grapefruit, and watermelon), vitamin D, vitamin E, and
the mineral selenium may lower prostate cancer risk. Current studies are
assessing whether these substances actually reduce risk.
Until such studies are completed, the best advice to lower prostate cancer risk is to
eat fewer red meats and high-fat dairy products and to eat 5 or more servings of
vegetables and fruits each day.
Physical Inactivity - Regular physical activity and maintaining a healthy weight
may help reduce prostate cancer risk.
Prostate Cancer Prevention - Risk factors you can not change
There are sever risk factors that are unavoidable. It may be important for people with
these risk factors to take extra care in trying to prevent the disease.
Race - Prostate cancer occurs almost 70% more often in
African-American men as it does in white American men
Nationality - Prostate cancer is most common in North America and northwestern
Europe. It is less common in Asia, Africa, Central America, and South America.
Age - The chance of having prostate cancer increases rapidly after age 50. More
than 70% of all prostate cancers are diagnosed in men over the age of 65. It is still
unclear why this increase with age occurs for prostate cancer.
Other things you can do.
Prostate Cancer
Prevention - lycopene
DETROIT, MICHIGAN. Epidemiological studies have shown that a high intake of tomatoes
markedly reduces the risk of prostate cancer. It is believed that this beneficial effect
is due to lycopene, the most common carotenoid in tomatoes. A team of researchers from
Wayne State University, McGill University, University of Maryland, and the University of
Hawaii has just concluded a clinical trial aimed at evaluating the benefits of lycopene
supplementation in prostate cancer patients. The study included 26 men with clinically
localized prostate cancer who were scheduled to undergo radical prostatectomy (removal of
the prostate gland). The men were randomized into a control group and an intervention
group. The intervention group received one 15-mg lycopene capsule with breakfast and
dinner for three weeks prior to surgery. Blood samples were taken before the start of
supplementation and three weeks later just before surgery. The removed tumors and surrounding tissue were examined by
pathologists.
The researchers conclude that lycopene supplementation lowers PSA levels; they observed an
average 18 per cent decrease in the lycopene group as compared to a 14 per cent increase
in the control group. The level of the tumor suppressing protein Cx43 in the malignant
part of the tumor was found to be substantially higher in the lycopene group. It was also
apparent that tumors tended to be smaller and more sharply defined (less encroachment into
surrounding healthy tissue) in the lycopene group. No adverse effects of the lycopene
supplementation were reported by the patients or their physicians. The researchers
conclude that lycopene is likely to be beneficial for both prevention and treatment of
prostate cancer, but urge larger trials to confirm this.
Kucuk, Omer, et al. Phase II randomized clinical trial of lycopene supplementation
before radical prostatectomy. Cancer Epidemiology, Biomarkers & Prevention, Vol. 10,
August 2001, pp. 861-68 [72 references]
Prostate Cancer Prevention - Sun exposure
STAFFORDSHIRE, UNITED KINGDOM. British researchers have confirmed that exposure to
sunlight helps prevent prostate cancer. Their study involved 210 men diagnosed with
prostate cancer and 155 men with an enlarged prostate, but no prostate cancer (controls).
The men were interviewed in order to estimate their lifetime sun exposure. Men with the
lowest exposure were found to have a three times greater incidence of prostate cancer than
did men with a high lifetime exposure. Sunburns in childhood were found to be particularly
protective with men having had one or more childhood sunburns being six times less likely
to develop prostate cancer than men who had not experienced childhood sunburns.
A history of regular foreign holidays, presumably in sunnier climes, also had a protective
effect with men having had such holidays having a 60 per cent lower risk of prostate
cancer. Regular sun bathing was also found to be protective. The risk of prostate cancer
was not associated with skin type, hair colour or eye colour, and the associations with
sun exposure were not affected by including occupation, vasectomy or dietary factors in
the analysis.
The researchers are not sure why sun exposure is protective, but speculate that vitamin D
and parathyroid hormone may somehow be involved. Editor's Note: Excessive sun
exposure has been linked to an increased risk of certain non-melanoma skin cancers. These
cancers, however, are rarely fatal whereas prostate cancer often is. So on balance,
cultivating a healthy suntan is still a good idea.
Luscombe, Christopher J., et al. Exposure to ultraviolet radiation: association with
susceptibility and age at presentation with prostate cancer. The Lancet, Vol. 358, August
25, 2001, pp. 641-42 (research letter)
Prostate Cancer Prevention - Fish consumption
STOCKHOLM, SWEDEN. Several studies have shown an inverse relationship between blood
levels of fish oils (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) and the
risk of prostate cancer. A study just completed by medical researchers at the Karolinska
Institute confirms this association.
The Swedish study involved 3136 pairs of male twins born between 1886 and 1925. The
participants completed food frequency questionnaires in 1961 and 1967 and were then
followed up for 30 years. By December 31, 1997 the researchers had recorded 466 diagnoses
of prostate cancer (340 fatal ones). The average age of diagnosis was 76.7 years. After
adjusting for other known risk factors the researchers conclude that men who never eat
fish have a two- to three-fold higher risk of prostate cancer than do men who eat moderate
to high amounts. The researchers emphasize that only fatty fish such as salmon, herring
and mackerel, which contain high amounts of omega-3 fatty acids (EPA and DHA), would be
expected to be beneficial.
Terry, Paul, et al. Fatty fish consumption and risk of prostate cancer. The Lancet,
Vol. 357, June 2, 2001, pp. 1764-66 (research letter)
Prostate Cancer Prevention - Lycopene
TORONTO, CANADA. Lycopene is a carotenoid found in tomatoes, tomato products, and in
other fruits. It is a powerful antioxidant with a singlet-oxygen quenching capacity 10
times greater than that of vitamin E. It is the most abundant carotenoid in human plasma
and is highly concentrated in the adrenal glands, testes, prostate, and breast tissue.
Several studies have found an inverse correlation between serum and tissue levels of
lycopene and the risk of breast and prostate cancers. Other studies have linked a
high intake of tomatoes to a 50 per cent reduction in cancer mortality among elderly
Americans. One study found that men who consumed 10 or more servings of tomato products
per week reduced their risk of prostate cancer by 35 per cent. A more recent study found
that supplementation with a tomato extract significantly lowered the level of
prostate-specific antigen (PSA) in patients with prostate cancer. High tissue (adipose)
levels of lycopene have also been found to be protective against heart attacks. No
published studies have shown any adverse effects of high lycopene levels or a high intake
of tomato products. It has been hypothesized that lycopene prevents cancer and heart
disease by protecting lipids, lipoproteins (especially low-density lipoprotein), proteins,
and DNA. There is also evidence that lycopene counteracts the proliferation of cancer
cells induced by insulin-like growth factors.
Agarwal, Sanjiv and Rao, AV. Tomato lycopene and its role in human health and chronic
diseases. Canadian Medical Association Journal, Vol. 163, September 19, 2000, pp. 739-44
[70 references]
Prostate Cancer Prevention - Fruits and Vegetables
SEATTLE, WASHINGTON. There is abundant evidence that a high intake of fruits and
vegetables is protective against many types of cancer. Researchers at the Fred Hutchinson
Cancer Research Center now report that the intake of vegetables, but not fruits, is
significantly associated with prostate cancer risk. Their study involved 628 men from the
Seattle area between the ages of 40 and 64 years who had been diagnosed with prostate
cancer between January 1 and December 31, 1996. An age-matched sample of 602 men without
prostate cancer served as the control group. All participants were interviewed and
completed a 99-item food frequency questionnaire which included 12 fruit items and 21
vegetable items. The participants were asked to estimate their intake of the foods
(ranging from "never or less than once per month" to "2+ per day")
over the 3-5 years preceding the date of diagnosis or date of interview (for controls).
The intake of fruit did not significantly affect prostate cancer risk. However, men who
consumed 28 or more servings of vegetables per week were found to have a 35 per cent lower
risk than men who consumed fewer than 14 servings per week. When limiting the analysis to
cruciferous vegetables only the protective effect was found to be even more pronounced.
Men who ate three or more servings of cruciferous vegetables (broccoli, cauliflower,
brussel sprouts, cabbage) per week had a 41 per cent lower risk of developing prostate
cancer than did men who ate less than one serving a week. A high intake of lutein plus
zeaxanthin (2000 micrograms/day or more) was associated with a 32 per cent decrease in
risk, but this association was not statistically significant. The researchers found no
correlation between the intake of tomato products or lycopene and prostate cancer risk.
Cohen, Jennifer, et al. Fruit and vegetable intakes and prostate cancer risk. Journal
of the National Cancer Institute, Vol. 92, January 5, 2000, pp. 61- 68
Prostate Cancer Prevention - Fish oils
AUCKLAND, NEW ZEALAND. Medical researchers in New Zealand provide convincing evidence
that an increased consumption of fish oils helps reduce the risk of developing prostate
cancer. Their study involved 317 men who had been diagnosed with prostate cancer during
1996-97 and 480 age-matched controls. Blood samples were obtained from all participants
and the erythrocyte (red blood cell) phosphatidylcholine fraction of the plasma was
analyzed for EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), the two main
components of fish oils.
Evaluation of the collected data showed a clear correlation between blood level of EPA
and DHA and the presence of prostate cancer. Study participants with levels in the highest
quartile were found to have a 40 per cent lower incidence than participants with levels in
the lowest quartile. This relationship held true even when adjusted for age, height, use
of NSAIDs (non- steroidal anti-inflammatory drugs), socio-economic status, and estimated
intake of lycopene and polyunsaturated fats.
The researchers also found that men with low socio-economic status, a low intake of
lycopene, and non-regular use of NSAIDs were more likely to develop prostate cancer. They
did not, however, find any correlation between self- reported intake of EPA and DHA
indicating that food frequency questionnaires are not an accurate method for estimating
fish oil intake. The researchers speculate that fish oils may prevent the progression of
prostate cancer by inhibiting the biosynthesis of eicosanoids from arachidonic acid.
Norrish, A.E., et al. Prostate cancer risk and consumption of fish oils: a dietary
biomarker-based case-control study. British Journal of Cancer, Vol. 81, No. 7, December
1999, pp. 1238-42
Prostate Cancer Prevention - Diet
SACRAMENTO, CALIFORNIA. It is estimated that 35% of all cancers are directly associated
with the typical American diet; another 30% is directly related to smoking. A high fat
intake is associated with cancer of the colon, breast, prostate, rectum, and endometrium.
These cancers are also associated with obesity as are cancers of the kidney, cervix, and
thyroid. Alcohol consumption is implicated in cancers of the breast, rectum, mouth, and
esophagus. The consumption of charred, smoked, salted, and pickled foods is associated
with cancer of the stomach and esophagus. On the other hand, an increased fiber intake has
been found to protect against colon cancer - presumably because it speeds up elimination
of waste through the bowels. An increased consumption of fruit and vegetables has been
found to have a protective effect against lung, colon, breast, prostate, bladder, mouth,
cervix, and stomach cancer. The Amercian Cancer Society has recommended that efforts be
made to change the typical American diet so that it contains no more than 30% fat (% of
total calories) - in 1985 the average diet contained 36%. It also recommends 5 or more
servings of fruit and vegetables per day (1986 average was 2.5) and 6 or more servings a
day of breads, cereals, and legumes (1986 average was 3). The Society would like to see
these dietary changes implemented by the year 2000 and estimates that 166,000 cancer
deaths and 315,000 new cases of cancer could be avoided every year if they were.
Bal, Dileep G. and Foerster, Susan B. Dietary strategies for cancer prevention. Cancer
(Supplement), Vol. 72, No. 3, August 1, 1993, pp. 1005- 10
Byers, Tim. Dietary trends in the United States. Cancer (Supplement), Vol. 72, No. 3,
August 1, 1993, pp. 1015-18
Tomato sauce protects against prostate cancer
BOSTON, MASSACHUSETTS. It is estimated that by the year 2000 about 40,000 men will die of
prostate cancer every year in the United States alone. So far, no effective prevention has
been found and treatment is of dubious value and has serious side effects. Now researchers
at the Harvard Medical School report that consumption of tomato sauce and tomatoes
provides significant protection against the development of prostate cancer. Their study
involved over 47,000 male health professionals 812 of which developed prostate cancer in
the period between 1986 and 1992. All participants in the study completed validated
food-frequency questionnaires in 1986, 1988, 1990 and 1992. Analysis of the collected data
clearly showed that men with a high consumption of tomato sauce, tomatoes, and pizza have
a significantly lower risk of developing prostate cancer. The protective effect of tomato
sauce (ripe tomatoes cooked in oil) was particularly noteworthy; men who consumed tomato
sauce two to four times per week had a 35 per cent lower risk of developing prostate
cancer than did men who never ate tomato sauce. The researchers believe that it is the
high content of lycopene which gives tomato products their protective effect. They also
speculate that oil or fat is necessary for proper absorption of the lycopene from the
tomatoes. Tomato juice on its own has no protective effect and its lycopene is poorly
absorbed. However, if tomato juice is cooked in oil and then ingested the blood level of
lycopene rises very significantly within 24 hours. The researchers believe that lycopene
protects against prostate cancer because it is a very powerful antioxidant, more than
twice as effective as beta-carotene, and because it is the most abundant carotenoid in the
prostate gland. No protective effect was found for vitamin A, beta- carotene,
alpha-carotene, lutein or beta-cryptoxanthin. The researchers also found that a high
intake of fruit and vegetables other than tomatoes had no significant protective effect.
Giovannucci, Edward, et al. Intake of carotenoids and retinol in relation to risk of
prostate cancer. Journal of the National Cancer Institute, Vol. 87, No. 23, December 6,
1995, pp. 1767-76 |