To investigate the relationship between erythrocyte membrane polyunsaturated fatty acid (PUFA) and serum prostate- specific antigen (PSA) levels in Jamaican men, as there may be an association between prostate cancer incidence and dietary fatty acids, and prostate cancer incidence in Jamaica is among the highest in the world.
Blood from 107 Jamaican men was analysed for 32 individual fatty acids and PSA levels. Special attention was given to correlations between Omega3 and Omega6 PUFAs and PSA. Data were analysed using standard linear regression methods.
The mean PSA was 18.6 ng/mL (normal 0-4.0); for age groups of 51-60, 61-70 and 71-80 years the levels were 14, 26 and 23 ng/mL, respectively. Eicosapentaenoic acid (Omega3) levels decreased as PSA exceeded 10 ng/mL (P = 0.02). Arachidonic acid (Omega6) levels decreased as PSA was < 2 ng/mL (P = 0.02). Linoleic acid (Omega6) levels decreased in men with PSA levels of 2-10 ng/mL (P = 0.04). In men with a PSA of > 10 ng/mL there was a positive correlation between the ratio of Omega6 to Omega3 PUFAs and PSA (P = 0.036); there was also a negative correlation between the ratio of Omega3 to Omega6 PUFAs and PSA (P = 0.08). When the ratio of Omega3 PUFAs over the products of Omega6 PUFAs were used, this trend was significant (P= 0.03).
Increased levels of Omega6 PUFAs and the ratio of Omega6/Omega3 PUFAs in Jamaican men are associated with an increased mean PSA level and risk of prostate cancer. Additional studies are needed to establish a causal link between dietary fatty acid intake and the development of prostate cancer in Jamaican men.