3 popular supplements fall short in preventing prostate cancer: study

May 6, 2011 by Deborah Braconnier report

(PhysOrg.com) -- For some time it has been believed that vitamin E, selenium and soy were natural ways to prevent prostate cancer. However, a new study published in the Journal of Clinical Oncology shows that these supplements do not provide any additional benefit when it comes to prostate cancer prevention.

Dr. Neil Fleshner, head of the urology department at the University Health Network in Toronto led the study on 303 men. All the men chosen for the study were at high risk for prostate cancer as they already showed pre-cancerous cells.

The researchers randomly chose men to receive the supplements while the others received a . These men were required to take these supplements every day for three years. The supplements contained a combination of 40g of soy, 800U of , and 0.2 milligrams .

After three years, the results of both groups came back the same. Within each group, 26 of every 100 developed prostate cancer. These results are similar to a study that was done in 2008 on vitamin E and selenium, where no benefit was found.

Researchers had hoped that the addition of soy in this study would show promise. In countries like China and Japan, where soy is eaten in large amounts, the rates of prostate cancer are much lower than those in the United States and Canada. Fleshner says that this does not rule out the benefits of a soy based diet for decades, but that three years of soy was not enough to show a change.

With 156 out of 10,000 men developing each year, Fleshner believes that this study provides enough proof that continued research into the benefits of these supplements should be abandoned and research funds turned to other possible ideas.

More information: Progression From High-Grade Prostatic Intraepithelial Neoplasia to Cancer: A Randomized Trial of Combination Vitamin-E, Soy, and Selenium, Journal of Clinical Oncology Published online before print May 2, 2011, doi:10.1200/JCO.2010.32.0994

Purpose High-grade prostatic intraepithelial neoplasia (HGPIN) is a putative precursor of invasive prostate cancer (PCa). Preclinical evidence suggests vitamin E, selenium, and soy protein may prevent progression of HGPIN to PCa. This hypothesis was tested in a randomized phase III double-blind study of daily soy (40 g), vitamin E (800 U), and selenium (200 μg) versus placebo.
Patients and Methods Three hundred three men in 12 Canadian centers were analyzed. The main eligibility criterion was confirmed HGPIN in at least one of two biopsies within 18 months of random assignment. Treatment was administered daily for 3 years. Follow-up prostate biopsies occurred at 6, 12, 24, and 36 months postrandomization. The primary end point was time to development of invasive PCa. Kaplan-Meier plots and log-rank tests were used to compare two treatment groups for this end point.
Results For all patients, the median age was 62.8 years. The median baseline prostate-specific antigen (PSA; n = 302) was 5.41 ug/L; total testosterone (n = 291) was 13.4 nmol/L. Invasive PCa developed among 26.4% of patients. The hazard ratio for the nutritional supplement to prevent PCa was 1.03 (95% CI, 0.67 to 1.60; P = .88). Gleason score distribution was similar in both groups with 83.5% of cancers graded Gleason sum of 6. Baseline age, weight, PSA, and testosterone did not predict for development of PCa. The supplement was well tolerated with flatulence reported more frequently (27% v 17%) among men receiving micronutrients.
Conclusion This trial does not support the hypothesis that combination vitamin E, selenium, and soy prevents progression from HGPIN to PCa.

Related Stories

Recommended for you

Researchers discover a new target for 'triple-negative' breast cancer

November 20, 2017
So-called "triple-negative" breast cancer is a particularly aggressive and difficult-to-treat form. It accounts for only about 10 percent of breast cancer cases, but is responsible for about 25 percent of breast cancer fatalities.

Clinical trial suggests new cell therapy for relapsed leukemia patients

November 20, 2017
A significant proportion of children and young adults with treatment-resistant B-cell leukemia who participated in a small study achieved remission with the help of a new form of gene therapy, according to researchers at ...

Study reveals new mechanism used by cancer cells to disarm attacking immune cells

November 20, 2017
A new study by researchers at The Ohio State University Comprehensive Cancer Center - James Cancer Hospital and Solove Research Institute (OSUCCC - James) identifies a substance released by pancreatic cancer cells that protects ...

Cell-weighing method could help doctors choose cancer drugs

November 20, 2017
Doctors have many drugs available to treat multiple myeloma, a type of blood cancer. However, there is no way to predict, by genetic markers or other means, how a patient will respond to a particular drug. This can lead to ...

Lung cancer triggers pulmonary hypertension

November 17, 2017
Shortness of breath and respiratory distress often increase the suffering of advanced-stage lung cancer patients. These symptoms can be triggered by pulmonary hypertension, as scientists at the Max Planck Institute for Heart ...

Researchers discover an Achilles heel in a lethal leukemia

November 16, 2017
Researchers have discovered how a linkage between two proteins in acute myeloid leukemia enables cancer cells to resist chemotherapy and showed that disrupting the linkage could render the cells vulnerable to treatment. St. ...


Adjust slider to filter visible comments by rank

Display comments: newest first

5 / 5 (1) May 06, 2011
the title of this unbiased paper should be "vitamin E, selenium and soy fall short in preventing prostate cancer". Otherwise you people should use general labels to report all research. For example, "pharmaceuticals failed to stop infections" because three pharmaceuticals drugs failed containing a disease....
not rated yet May 10, 2011

I think vitamin D would have a better chance. It has been shown to prevent several other types of cancer, in various studies, performed at University of California Medical Centers, as well as those of other universities.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.