Prostate cancer and current recommendations for vitamin E

09 November 2005 Filed under Prostate Cancer, Selenium, Vitamin E Posted by » No Comments

As reported, A Protein That Helps Maintain Vitamin E Levels Suppresses Prostate Cancer, University of Rochester Medical Center researchers have found an organic protein in the body, a protein, that helps prostate cancer cells retain vitamin E. This helps vitamin E to limit the growth of the cancer.

This protein, which they call scientists have named alpha tocopherol associated protein, or TAP, suppresses growth of the cancer by disrupting an important signaling pathway in prostate cancer cells.

A reader asks, for men with prostate cancer would it help to take a high quality vitamin E pill?

We don’t really know. Last year a controversial study from Johns Hopkins found that, especially in older people, consumption of current maximum dose of vitamin E was associated with a higher death rate.

People who took daily vitamin E doses exceeding 400 “international units” (IU) per day (equivalent to about 270mg) had an increased risk of death by about 10% compared with those who did not. Some commentators suggested that the Hopkins study was flawed because people who are already sick (or who feel weak or out of sorts) may take more vitamins than healthy people do. Others said the study failed to take due acount of the type of vitamin E consumed. Most of the participants took alpha-tocopherol. Mixed tocopherols are considered superior. A Purdue University scientist found that in his lab, vitamin E Gamma (which is high in plant seeds) tamed prostate and lung cancer cells.

An ongoing clinical trial, the Selenium and Vitamin E Cancer Prevention Trial (SELECT), sponsored by NCI, began in July 2001 with the aim of finding out if these two dietary supplements can protect against prostate cancer. The aim is to randomize 32,400 men to receive daily supplements of either: selenium and vitamin E (alpha-tocopherol); selenium and placebo; vitamin E and placebo; two placebos. The trial is expected to end in 2013.

Although it has not yet reported, 4 years ago the National Cancer Institute said that a trial in Finland, called the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC Study) “showed that 50- to 69-year-old men who took 50 mg of alpha-tocopherol (a form of the antioxidant vitamin E) daily for five to eight years had 32 percent fewer diagnoses of prostate cancer and 41 percent fewer prostate cancer deaths compared with men who did not receive vitamin E. This dose of vitamin E is equal to about 50 international units (the measure more commonly used with supplements) and is about three times the Recommended Dietary Allowance.

The 29,133 male smokers from Finlandwere randomly assigned to receive alpha-tocopherol, beta-carotene (20 mg), or a placebo (an inactive pill that looked like the vitamin) daily.”

Men taking beta-carotene did not fare as well as men on placebo, they had more cardiovascular disease and lung cancer and a higher death rate. Men taking vitamin E had a lower rate of prostate cancer while they were taking the supplement and for a couple of years after stopping. The effects wore off.

“In men taking the vitamin E, there was a reduction in clinically detectable prostate cancers beginning within two years of starting the supplement – a result which suggests to Philip R. Taylor, M.D., Sc.D., chief of NCI’s Cancer Prevention Studies Branch, that vitamin E may be blocking a prostate tumor’s progression to a more aggressive state. Most older men have microscopic areas of cancer in their prostate, few of which will progress to life-threatening disease.”

“We know that prostate cancer develops first as latent cancer that can’t be detected clinically,” said Taylor. “For some men, these tumors are transformed from sub clinical cancer – which may never affect a man’s health – into aggressive disease. We think vitamin E is working by blocking the changeover from these more benign tumors to potentially life-threatening disease.”

More about this trial here

Let’s look at what Dr. Steven Strum’s PCRI has to say about vitamin E:

“The recommended dose of vitamin E for patient with prostate cancer is 800-1,200 mg per day. Higher doses of vitamin E can have blood-thinning effects and can cause bleeding tendencies, and are not recommended. Vitamin E, selenium and zinc are intimately involved in
a number of complimentary cellular enzyme systems. Therefore, supplementation with vitamin E should always be done in conjunction with selenium and zinc supplementation. Vitamins E and C also work side by side in antioxidant systems and supplementation programs should balance these vitamins.”
http://www.prostate-cancer.org/education/nutrprod/vite.html

Recommended by whom? I think Dr. Strum & colleagues are recommending what they consider to be the safest maximum amount a man can take. But is that a stretch from the point of view of safety of older men? Any more than than and you’re certainly risking a stroke.

Participants in the Finnish trial taking vitamin E had 32 percent fewer cases of prostate cancer and 41 percent fewer deaths from prostate cancer. But “Death from hemorrhagic stroke (a deficit of blood to the brain due to the rupture of a blood vessel) was also increased by 50 percent in men taking alpha-tocopherol supplements; the increase occurred primarily among men with hypertension.” (Journal of the National Cancer Institute 1998;90:440 and Arterioscler Thromb Vasc Biol 2000;20:230).

Before taking vitamin E above the standard recommended daily dose, talk to your own doctor. Reviews of some brands of vitamin E and vitamin E products are at Consumer Lab.

.

Trackback URL

No Comments

You must be logged in to post a comment.