Prostate Cancer and Selenium Intake
Prostate cancer presents a very real risk to life and
longevity. The incidence of prostate
cancer rises dramatically with age.
Genetic predisposition does play a role in the risk of prostate cancer,
but it is difficult to change the structure and nature of the gene thereby
mitigating cancer risk. It is, however,
fairly easy to alter some environmental risk factors that dramatically improve
risks for disease development.
Evidence suggests a significant link between prostate
enlargement (BPH) and hormonal levels. As males age, production of androgenic (male)
hormones decreases, causing an imbalance in androgen and estrogen levels, and
high levels of dihydrotestosterone (DHT), the main prostatic intracellular
The likelihood of developing an enlarged prostate
increases with age.Prostate enlargement is present in many males older than age
40, and prostate enlargement is present in more than 90% of males older than the
age of 80.
Blacks have a higher incidence of prostate cancer, with an
incidence rate of 224.3 cases per 100,000 people, and blaks are at the greatest
risk to present with more advanced neoplastic disease associated with a poorer
diagnosis. Whites, by comparison, have an incidence of 150.3 cases per 100,000
people, and Asians have an incidence of
82.2 cases per 100,000 people.
Selenium: At least five
major clinical trials have concluded that higher levels of selenium (in blood
or toenail clippings) are associated with a sharply reduced risk of prostate
cancer. The Nutritional Prevention of Cancer (NPC) trial found that
supplementing with 200 micrograms/day of selenium cuts prostate cancer risk in
half. Researchers at the
School now weighs in with another study confirming the beneficial effects of selenium.
Their study involved 22,000 healthy, male physicians who were enrolled in the
study in 1982 and had blood samples taken at that time. Sufficient samples to
analyze for selenium content and PSA level were available for 586 men diagnosed
with prostate cancer as well as for 577 controls matched for age and smoking
13 years of follow-up the researchers concluded that study participants with a
plasma selenium level of 0.12-0.19 ppm had a 50% lower incidence of advanced
prostate cancer than did men with a level of 0.06-0.09 ppm. The correlation was
only apparent in men with a PSA level of more than 4 ng/mL and was particularly
strong for those with a baseline (1982) PSA level greater than 10 ng/mL. For
these men a high selenium level corresponded to a 70% decrease in the risk of
advanced prostate cancer. The researchers also observed a trend for a lower
incidence of localized prostate cancer with high selenium levels, but this
trend was not statistically significant. They conclude that selenium is perhaps
not too effective in preventing the initiation of prostate cancer, but that it
is highly effective in slowing down tumor progression. They believe that
selenium acts by selectively killing off cells whose DNA has been extensively
damaged, by inhibiting cellular proliferation, and by its role as a key
component of glutathione peroxidase, which protects cells from peroxide damage.
NOTE WELL: Selenium is very inexpensive and easy to obtain. Too much is poisonous. Recommended dosages should not be exceeded. A good starting point is 200 mcg/day increase to 400 or 600, with care and only under the supervision of a physician who understands the implications of the use of interventional nutrition and nutraceuticals.