According to the World Health Organization, prostate cancer is the third-most common cancer in men worldwide, with 250,000 new cases diagnosed each year. In terms of general cancer prevention, omega-3 fish oil has attracted a lot of attention; however, scientific scrutiny into the pathways leading to fish oil's health benefits has called into attention the possibility that an imbalance of omega-3 and omega-6 oils in the diet might be at the root of many health problems. The evidence is very striking with respect to prostate cancer incidence.
Omega-3 and Omega-6 Fatty Acids
Because an imbalance in dietary omega-3 and omega-6 fatty acids has been implicated in causing prostate cancer, it's important to understand the food sources of these micronutrients. The primary source of omega-3 fatty acids is marine animals, with fatty fish the best source. Plant sources include nuts and seeds. In terms of omega-6 fatty acids, these are abundant in vegetable oils, including corn, sunflower, safflower and soybean oils. According to the National Institutes of Health, omega-6s are hidden in margarine, burgers and beef dishes. These three food categories supply most of the omega-6s in American diets.
Omega-3s Curb Prostate Cancer
The components of fish oil omega-3s that appear to have cancer-fighting properties are docosahexaenoic acid, or DHA, and eicosapentaenoic acid, or EPA. A team of English researchers led by Dr. Mick Brown and reporting in the March 2006 issue of the "British Journal of Cancer" concluded that diets rich in omega-3 fatty acids might help to inhibit the spread of the disease in men with early prostate cancer. The researchers found that supplementation of EPA and DHA had the ability to completely stop the spread of prostate cancer cells when omega-6 acids also were present in lipid profiles.
Omega-6s Speed Prostate Cancer Growth
In Dr. Brown's study, the researchers observed that a metabolite of omega-6 fatty acid named arachidonic acid actually accelerated the spread of prostate cancer cells into bone marrow cells; however, in the presence of EPA and DHA, the spread was halted. The effect was noted when omega-3s were present in just half the amount of omega-6s. Dr. Brown noted that it is possible to have a healthy balance of these two types of fatty acids by ensuring intake of omega-3s is at least 50 percent of the amount of dietary intake of omega-6s.
Flaxseed Omega-3s
Flaxseed contains precursors to omega-3s known as alpha-linolenic acid, which is metabolized into EPA and DHA by the body. In the October 2004 issue of "Nutrition Journal," Dr. Michael Donaldson published a review of studies examining the cancer-fighting potential of several nutrients and found an interesting study in which flaxseed as a source of omega-3s made significant positive differences in the biological markers doctors use to determine candidates for prostate cancer surgery. Study participants showed improvement in these markers after following a low-fat diet supplemented with 30 g of ground flaxseed every day for 34 days.
References
- World Health Organization: Global Cancer Rates
- National Cancer Institute: Cancer Risk Factor Monitoring
- "British Journal of Cancer"; Promotion of Prostatic Metastatic Migration Towards Human Bone Marrow Stoma by Omega-6 and Its Inhibition by Omega-3; Mick Brown et al.; March 2006
- "Nutrition Journal"; A Review of the Evidence for an Anti-cancer Diet; Michael Donaldson; October 2004
Member Comments