Decreasing Omega-6 to Omega-3 Polyunsaturated Fatty Acid Ratios Inhibit Tumorigenesis in Prostate Cancer Cells in Vitro

Abstract

Prostate cancer is the most commonly diagnosed cancer in American men. Currently, there are different treatment options depending on the situation, for instance, hormone therapy is a common treatment which reduces the levels of androgens. However, prostate cancer that is more aggressive or in an advanced stage can become unresponsive to hormonal treatment. This type of prostate cancer is referred to as hormone refractory prostate cancer. In many epidemiology studies, they have shown that diets low in omega- 6 polyunsaturated fatty acids (PUFAs), and rich in omega-3 PUFAs display a lower incidence of cancer. A particular type of omega-6 fatty acid, docosahexaenoic acid (DHA), has shown to decrease the growth of cancer cells. Therefore, DHA may have potential therapeutic effects on treating cancer. However, the current diet consists of low omega-3 content while very high omega-6 content. For example, the western diet (United States) consists of a ratio of about 16:1 (omega-6 to omega-3). In this tissue culture study, varying ratios of omega-6 to omega-3 polyunsaturated fatty acids (PUFAs) were tested to determine which ratio representing a human diet inhibited growth of PC-3 human prostate adenocarcinoma cell the most, which is a hormone refractory prostate cancer. The results showed that as the ratio decreased, the growth of prostate cancer cell decreased. The most optimal ratio was found to be 1:2 omega-6 to omega-3. However, the 4:1 ratio displayed the most practical dietary ratio to inhibit prostate cancer.