Omega 3 and Prostate Health
Omega-3 fatty acids are a type of essential fatty acid that the body needs for optimal health. They are “essential” because the body cannot manufacture them, so you must get them from food and/or supplements (e.g., fish oil, flaxseed oil). The three types of omega-3 fatty acids are EPA (eicosapentaenoic acid), DHA (docosahexaenoic acid), and ALA (alpha-linolenic acid). EPA and DHA offer the most health benefits. ALA is less available because it must be converted in the body to EPA and DHA. Unfortunately the conversation rate is 10 percent at best, and so it is very difficult to get the amount of recommended omega-3 from ALA.
Omega-3 fatty acids belong to a broader category of fats called polyunsaturated fats (PUFAs) because they have multiple double chemical bonds. These fatty acids calm the inflammatory response and thus prevent tissue damage and swelling that lead to pain and illness. Other benefits of omega-3 fatty acids include the ability to:
- Prevent excessive blood clotting
- Lower the amount of cholesterol and triglycerides in the bloodstream
- Maintain the fluidity of the cell membranes, which is essential for cells to grow and maintain health
- Facilitate the ability of the arteries to relax and dilate, good for maintaining normal blood pressure and overall cardiovascular health
- Inhibit thickening of the arteries by decreasing endothelial cells’ production of a substance called platelet-derived growth factor, also good for blood pressure and cardiovascular health
- Reduce the risk of becoming obese by improving the body’s ability to respond to insulin by stimulating the secretion of leptin, a hormone that helps regulate food consumption, body weight and metabolism, and is expressed mainly by fat cells
- Help prevent cancer cell growth, including prostate, esophageal, and colorectal cancer
Omega 3 and Prostate Cancer
One of the most promising studies about the benefits of omega-3s and prostate health was conducted by researchers from the University of California, San Francisco, and published in 2009. The investigators evaluated 466 men who had aggressive prostate cancer and 478 healthy men. All the men were asked to complete questionnaires about the foods they ate daily. They also were screened for a variant of the COX-2 gene that is known to increase a man’s risk for developing prostate cancer.
When the researchers analyzed all the collected data, they discovered that the men who ate dark, fatty fish rich in EPA/DHA (e.g., salmon) at least once a week had a 63 percent reduced risk of developing prostate cancer. The men who consumed little or no EPA/DHA and who also had the COX-2 variant were five times more likely to develop advanced prostate cancer. The researchers concluded that omega-3 fatty acids may decrease prostate inflammation and the progression of cancer by impacting the COX-2 gene. (Fradet 2009)
In a large study conducted at Harvard School of Public Health, researchers followed more than 20,000 men to determine the relationship between prostate cancer incidence and fish consumption. A total of 20,167 men who were part of the Physician’s Health Study were evaluated. The investigators found that of the men in the study who were diagnosed with prostate cancer, those who ate fish at least five times a week had a 48 percent lower risk of dying from the disease than the men who ate fish less than once a week. (Chavarro 2008)
A large Swedish study also evaluated the relationship between intake of fatty fish, COX-2, and prostate cancer. A total of 1,499 men who had prostate cancer who were already part of the CAPS study (Cancer Prostate in Sweden) were monitored along with 1,130 men who were cancer-free at the beginning of the study. The researchers determined that the risk of prostate cancer was 43 percent lower in men who consumed “salmon-like fish” one or more times per week when compared with men who never ate that type of fatty fish.
The investigators also analyzed the men’s intake of EPA and DHA and found that the men who consumed the highest amount of both EPA and DHA had a 30 percent less risk than men who consumed the least amount. In addition, men who possessed a variant of the COX-2 gene and who ate the most salmon-like fish had a 72 percent lower risk for prostate cancer when compared with men who had the COX-2 gene variant and who ate the least amount of salmon-type fish. The researchers also determined that a high intake of linoleic acid (an omega-6 fatty acid) increased the risk of prostate cancer. (Hedelin 2007)
In another study, researchers from the Harvard School of Public Health followed 47,866 men who had participated in the Health Professional Follow Up Study from 1986 until 2000. (Leitzmann 2004) The men were asked to complete food-frequency questionnaires and to include specific details about their use of cooking oil, the amount of dark-meat fish they ate, and if they used fish oil supplements. In the final analysis, the researchers found that consumption of ALA from meats, plants, and dairy sources increased the risk of advanced prostate cancer, while a high intake of EPA and DHA was associated with a decreased risk of total and advanced prostate cancer.
Results of the Prostate Cancer Prevention Trial were recently analyzed to determine if there was an association between blood levels of omega-3 and omega-6 fatty acids and prostate cancer. Although the investigators did not see a relationship between the fatty acids and the risk of low-grade prostate cancer, they did observe one between elevated levels of DHA (although not EPA, nor EPA plus DHA) and a greater risk of high-grade prostate cancer (Brasky 2011). In a communication ConsumerLab.com had with Dr. Theodore Brasky, the study’s lead author, Brasky explained that the study did not reflect supplement use and that he would soon be publishing a study showing no association between fish oil supplement use and prostate cancer risk. He also noted that previous research had found an association between fish consumption and a large reduction in late stage or fatal prostate cancer. (Szymanski 2010)
Omega 3, BPH, and Prostatitis
The omega-3s in fish oil may also help two other prostate problems, BPH and prostatitis. The anti-inflammatory activity of omega-3s may reduce the risk of prostatitis, while studies have shown that blood levels of omega-3 fatty acids are lower in men who have BPH.
The American Heart Association recommends consuming 0.5 to 1.8 grams of EPA and DHA daily either as fatty fish or supplements, or 1.5 to 3.0 grams of ALA daily to reduce the risk for heart disease. The Association also cautions that no one should consume more than 3 grams of omega-3 fatty acids per day unless they are under a doctor’s care, because high intake could cause excessive bleeding in some individuals.
The richest food sources of omega-3s in the form of EPA and DHA are certain fatty fish (e.g., anchovies, flounder, halibut, salmon, sardines, trout, tuna). For ALA, you can turn to walnuts, flaxseed, soybean oil, pumpkin seeds, hemp oil, chia seeds, and fortified foods.
Dr. Geo Espinosa, N.D., L.Ac, CNS, RH (AHG)
Brasky TM et al. Serum phospholipid fatty acids and prostate cancer risk: results from the Prostate Cancer Prevention Trial. Am J Epidemiol 2011 Apr 24
Chavarro JE et al. A 22-y prospective study of fish intake in relation to prostate cancer incidence and mortality. Am J Clin Nutr 2008 Nov; 88(5): 1297-303
Fradet V et al. Dietary omega-3 fatty acids, cyclooxygenase-2 genetic variation, and aggressive prostate cancer risk. Clinical Cancer Research 2009; 15: 2559.
Hedelin M et al. Association of frequent consumption of fatty fish with prostate cancer risk is modified by COX-2 polymorphism. Intl J Cancer 2007 Jan 15; 120(2): 398-405.
Leitzmann MF et al. Dietary intake of n-03 and n-6 fatty acids and the risk of prostate cancer. Am J Clin Nutr 2004 Jul; 80(1): 204-16.
Szymanski KM et al. Fish consumption and prostate cancer risk: a review and meta-analysis. Am J Clin Nutr 2010 Nov; 92(5): 1223-33