Omega 3 Linked To Prostate Cancer- Another “Fishy” Story

Every so often, a piece of health news will make a splash and trigger a major concern in the public.

This was certainly the case with a study published in the Journal of the National Cancer Institute, “Plasma Phospholipid Fatty Acids and Prostate Cancer Risk in the SELECT Trial.” The authors found an increased risk of prostate cancer among men with high blood concentrations of Omega-3 fatty acids.

In this study, plasma phospholipid omega-3 levels were measured in 834 men who eventually developed prostate cancer and 1393 men who did not.

Using standard statistical methods, they found that men in the highest concentrations of omega-3 had a 43% to 71% increased risk for prostate cancer (depending on severity).


The trial has a number of methodological flaws that have misled the public about the risk of omega-3 consumption and prostate cancer.

  • The study was not specifically designed to evaluate the relationship between omega-3 intake and prostate cancer risk so no firm conclusion can be drawn.

The participants in the study were all part of a larger study on the effects of vitamin E and selenium on prostate cancer.

The men in the study were assumed to be cancer-free but not confirmed by biopsy so there is no way to rule out any pre-existing cancer.

  • The measure of evaluating omega-3 intake in this study was plasma phospholipid levels, which is not considered a good index of long-term omega-3 consumption. Plasma phospholipid levels can be influenced dramatically by a single meal, or even the timing of a fish oil dose.

Therefore, looking at plasma levels may only provide insight into the recent intake of omega 3.

An accurate indicator of actual omega 3 levels is the red blood cell Essential Fatty Acid level test provided by Emed.

  • The study did not determine how the levels of Omega 3 were increased. There is no information on the volunteers’ eating habits regarding fish intake as well as fish oil supplementation, and yet the researchers try to blame supplements.

The study does not address the issue of contamination of marine foods and oils with pollutants and whether these might be influential in the development of cancer.

  • The researchers base their conclusions on a minuscule difference in omega-3 blood plasma phospholipid levels.

The blood levels of omega-3 fats in the patients that were considered to have a higher risk of prostate cancer were 4.66 percent. The blood levels of omega-3 in the control group were 4.48 percent.

  • One of the biggest drawbacks of this study is that it is retrospective. In other words, it looks back at old data.

Another “significant” correlation in the study was that the more a man smoked the less risk for prostate cancer he had. Wow. Does anyone believe that? If you follow the study, man should not only cut omega 3 but should start smoking.

Lastly, the following statement by the authors suggests that they may have significant bias: “There is really no evidence that taking dietary supplements is beneficial to health, and there is increasing evidence that taking high doses is harmful.” Such a statement shows a clear axe to grind in light of a great deal of scientific evidence on the value of dietary supplementation.


Final Word:

Omega-3 fish oil is among the most well researched nutritional supplements. A great amount of studies provide sufficient evidence to state with confidence that omega-3s are beneficial for health.

The body of evidence still indicates that increased PUFAs and lower saturated fats is beneficial for reducing the risk of cancer development.

Eight major studies, including over 78,000 participants found no increase in cancer incidence from omega 3 supplementation.

If omega-3 fats were causing prostate cancer, we would expect that countries with the highest fish intake would have the highest rates of prostate cancer. We would also expect that the countries with the lowest fish intake would have the lowest rates of prostate cancer. And yet the opposite is far closer to the truth.

The worst thing about this study is that it may lead to many men abandoning the use of fish oil supplements.

Omega-3 fats provide a wonderful benefit for prostate cancer patients by blocking the functioning of omega-6 fats that cancer cells use as an energy source. It is believed that omega-3 fatty acids help the body by protecting the membranes that surround each cell in the body.

The beneficial Omega 3 Fatty Acids are deficient in most people. It is important to know what your levels are by testing with the Essential Fatty Acid red blood cells test. 

Choose your fish and krill oil supplements wisely and avoid poor quality over the counter supplements which are loaded with mercury and other pollutants.

Choose from the Emed’s high-strength pure fish oil with the highest quality

Hopefully the positive outcome of this study will be to stimulate more research into the role of omega-3 fatty acids in prostate health.


Further Reading:



Brasky TM, Darek AK, Song X, et al. Plasma phospholipid fatty acids and prostate cancer risk in the SELECT trial. JNCI J 2013. First published online: 10 July 2013, 10.1093/jnci/djt174

Bassett JK, Severi G, Hodge AM, et al. Plasma phospholipid fatty acids, dietary fatty acids and prostate cancer risk. Int J Cancer 2013, doi: 10.1002/ijc.28203

Terry P, Lichtenstein P, Feychting M, Ahlbom A, Wolk A. Fatty fish consumption and risk of prostate cancer. Lancet 2001; 357: 1764-6

Leitzmann MF, Stampfer MJ, Michaud DS, Augustsson K, Colditz GC, Willett WC, Giovannucci EL. Dietary intake of n-3 and n-6 fatty acids and the risk of prostate cancer. Am J Clin Nutr. 2004 Jul;80(1):204-16.

William Harris, PhD, Omega-3 Fatty Acids and Risk for Prostate Cancer, Health World