March 31, 2014

Dr. Virender Sodhi

The world of prostate cancer research and treatment is abuzz with the “condemning” conclusions from a pair of recent articles that have emerged from Selenium and Vitamin E Cancer Prevention Trial (SELECT).

In this study, up to 34000 men were followed for 7 years as part of a double-blind placebo controlled trial.[1] Subjects were divided into four groups, 1) receiving placebo and placebo, 2) placebo and selenium, 3) Vitamin E and placebo, 4) Vitamin E and Selenium. The researchers measured the overall risk of prostate cancer and the risk of aggressive prostate cancer. In the initial study, researchers found that there was no statistical difference between the rate of cancer among individuals in the four groups.

These results indicated that there was no benefit of Vitamin E and Selenium alone or in combination. More dramatic discoveries were presented in the follow-up analysis of the SELEC Trial data. Researchers found two major risks factors of prostate cancer.[2]

1) Men who had high levels of selenium in their body at baseline had a higher chance of developing prostate cancer with selenium supplementation.

2) Synthetic Vitamin E molecule, alpha-tocopherol had a greater chance of developing prostate cancer regardless of having high or low level of selenium at baseline.

On the basis of these results, researchers concluded that selenium supplementation in the presence of high selenium at baseline raises risk of prostate cancer and that supplementation of synthetic vitamin E led to high risk of prostate cancer and greater risk of aggressive prostate cancer. Some experts[1]  in the field of medicine have taken these results and started raising alarms about the risk of using natural vitamins, minerals, and herbal supplements.[3] Based on these results, the safety and efficacy of all of natural medicine is being questioned with the excuse of inadequate research.

The far-reaching conclusions of the extremists of the medical field are contrary to the principles of moderation that guide the practice of natural medicine. Taking a closer look at the SELEC Trial, certain flaws emerge in the design of the studies.

First, individuals with high selenium at baseline were allowed to receive selenium supplementation. In such cases, it is reasonable to expect excessive activity of selenium dependent enzymes in these individuals. Over-activity selenium-dependent proteins may lead to physiologic imbalances and may have increased risk of cancer.

Second, subjects were given a synthetic form of alpha-tocopherol, which is an inherently unnatural “natural supplement”. Additionally, dietary vitamin E from food comes in 8 different forms of which alpha-tocopherol is just one. Therefore, comparing supplementation of such unnatural compounds with natural sources of nutrition is imprudent.

A look at the broader body of research paints a different picture in the relationship of nutrition and prostate cancer. A meta-analysis of 12 studies looked at the relationship between selenium in individual’s bodies and the risk of prostate cancer.[4] After considering statistics form a sample of 12000 subjects, researchers found that prostate cancer has a ‘U’ shaped relationship with selenium levels in an individual’s body. Individuals with selenium levels between 0.85 – 0.94 ug/g had a 30% lower chance of developing prostate cancer. Individuals who had less or more selenium had a higher risk of prostate cancer. Indicating that balance is essential when it comes to dietary selenium and  any other supplement,  excess supplement can be harmful.

A Finnish study collected dietary information from over 29000 men and matched up data with the incidence of prostate cancer.[5] Patients were receiving naturally occurring eight forms of tocopherols and tocotrienols.  The study looked at Vitamin E use over the course of 19 years, capturing a lifestyle rather than a medical intervention. Researchers found that men with high levels of Vitamin E in their diet had a significantly lower risk of prostate cancer.

Additional natural compounds that have been shown to reduce the risk of prostate cancer include sulforaphanes and indole 3-carbinol found in cruciferous vegetables like cabbage, cauliflowers, brussels sprouts, broccoli, kales, etc. Lycopene found in tomatoes has also proven its healing capacity as part of a healthy diet.6,7 Among general dietary patterns, a study of 15,000 Seventh day Adventist men found that individuals following a  vegetable and fruit-based diet that is low in animal fats and proteins and high in vegetarian fats and proteins was protective against development of prostate cancer.[8] This study further solidifies the case for preventive benefits for plant-based medicinal compounds.

The fundamental principles of Natural medicine call on the individual to adhere to natural rhythms of life. This includes a balanced lifestyle and healthy seasonal diet with variety of fruits and vegetables. Using foods as medicine can have two major benefits over the use of synthetic nutraceuticals; 1) medicinal compounds in food are more diluted, therefore ensuring a more controlled exposure in terms of frequency and quantity of the compound. 2) The body has a greater opportunity to eliminate excess medicinal compounds and maintain functional physiological balance. In this way, functional nutritional interventions prove to be gentler and less harmful to the individuals than nutraceuticals.

References

  • [1] Lippman SM, et al. Effect of Selenium and Vitamin E on risk of prostate cancer and other cancers: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA, 2009; Vol. 301, Pg. 39-51.
  • [2] Kristal AR, et al. Baseline selenium status and effect of selenium and vitamin E supplementation on prostate cancer risk: comments and open questions. Journal of National Cancer Institute, 2014 Feb.
  • [3] Chodak G. Supplement Risk Exposed by SELECT. www.Medscape.com, March 2014;
  • [4] Hurst R, Hooper L, et al. Selenium and prostate cancer: systematic review and meta-analysis. American Journal of Clinical Nutrition, 2012; Vol. 96, Pg. 111–122.
  • [5] Weinstein SR, Wright ME, et al. Serum and Dietary Vitamin E in Relation to Prostate Cancer Risk. Cancer Epidemiol Biomarkers Prev, 2007; Vol. 16, Pg. 1253-1259.
  • [6] Canene-Adams K, Lindshield BL, et al. Combinations of Tomato and Broccoli Enhance Antitumor Activity in Dunning R3327-H Prostate Adenocarcinomas. Cancer Res 2007;67:836-843.
  • [7] Brosnan SA, et al. Prostate Cancer and Nutrition. Medscape.com, online article, Feb 24, 2012.
  • [8] Mills PK, Beeson WL, et al. Cohort Study of Diet, Lifestyle, and Prostate Cancer in Adventist Men. Cancer, 1989; Vol. 64, Pg. 598-604,