Prostate cancer: EPA decreases its development

Omega-3s found in the prostate slow cancer progression. In particular, the concentration of EPA (eicosapentaenoic acid) measured directly in prostate tissue, rather than in blood or estimated from dietary habits, is associated with less cancer progression.

This is what researchers at the University of Quebec (Canada) found in a study, published in the journal Cancer Prevention Research, carried out with the aim of clarifying the link between Omega-3 and prostate cancer.

What is the role of omega-3s?

Prostate cancer is the most frequent cancer in men. It accounts for about 30% of malignancies in the male population. Treatment varies according to its dangerousness, expressed by a low, medium or high risk class. The low-risk one can be monitored with sampling and biopsies, implementing so-called active surveillance and avoiding aggressive treatments to patients in suboptimal clinical condition. The association between Omega-3 and this type of cancer has been widely studied. However, little is still known about the impact of fatty acid content in the prostate with respect to disease progression. Discordant results have been published on this relationship; last summer, in a study Brasky and colleagues hypothesized that Omega-3s were associated with an increased risk of prostate cancer. Editorials and scientific reviews then argued that the link could not be confirmed.

EPA reduces disease progression

In this study, the researchers hypothesized that compared with the dietary estimate or the level measured in red blood cells, the Omega-3 content in prostate tissue was more strongly related to cancer progression. The research was conducted in a cohort of 48 untreated men with low-risk prostate cancer under active surveillance. Subjects underwent prostate tissue sampling within six months of initial diagnosis. In addition, polyunsaturated fatty acid levels were assessed with a food frequency questionnaire and determined in red blood cells. The results showed that EPA concentration, determined directly in the prostate, was associated with a reduced risk of progression, in patients with low-risk cancer.

Prostate tissue analysis is more effective 

In conclusion, Omega-3 concentrations in prostate tissue would be more strongly linked, and give more information about the likelihood of disease progression, than concentrations measured in red blood cells or from intake predictions. Measuring Omega-3 in blood is a better means of evaluation than assessing dietary intake, but not as effective as measuring EPA and DHA (docosahexaenoic acid) in red blood cell membranes; but even this has limitations because blood cells have a 90-day life span. For the researchers, therefore, measuring nutrient levels in the tissue of interest is the best approach to establish associations between nutrients and cancer risk. This study also confirms that omega-3 intake in men is often insufficient and falls short of the 250-500 mg per day doses of EPA and DHA.

Source: Moreel X, Allaire J, Leger C, Caron A, Labonte M-E, Lamarche B, Julien P, Desmeules P, Tetu B, Fradet V. Prostatic and dietary omega-3 fatty acids and prostate cancer progression during active surveillance. 2014 Cancer Prev Res doi: 10. 1158/1940-6207.CAPR-13-0349