Key Findings
Blood levels of prostate specific antigen (PSA) are used as a marker of prostate cancer. In this study, 2g ALA per day during 40 months increased serum PSA concentrations in older post myocardial infarction patients by 0.10 ng per mL but with a large confidence interval range from -0.02 to 0.22 mg per mL. Supplementation of ALA in this population did not result in an effect on PSA and thus effects on prostate cancer appear not to be of significance.
ABSTRACT
Alpha linolenic acid (ALA) is the major omega 3 fatty acid in the diet. Evidence on health effects of ALA is not conclusive, but some observational studies found an increased risk of prostate cancer with higher intake of ALA. We examined the effect of ALA supplementation on serum concentrations of prostate-specific antigen (PSA), a biomarker for prostate cancer. The Alpha Omega Trial was a double blind, placebo-controlled trial of ALA and the fish fatty acids eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) on the recurrence of cardiovascular disease, using a 262 factorial design. Blood was collected at the start and the end of the intervention period. The present analysis included 1622 patients with a history of a myocardial infarction, aged 60 to 80 years with an initial PSA concentration 4 ng per mL. They received either 2 g per day of ALA or placebo in margarine spreads for 40 months. T tests and logistic regression were used to assess the effects of ALA supplementation on changes in serum PSA (both continuously and as a dichotomous outcome, cut off point greater than 4 ng per mL). Mean serum PSA increased by 0.42 ng per mL on placebo (n 815) and by 0.52 ng per mL on ALA (n 807), a difference of 0.10 (95 confidence interval: -0.02 to 0.22) ng per mL (P of 0<12). The odds ratio for PSA rising above 4 ng per mL on ALA versus placebo was 1.15 (95 CI: 0.84-1.58). An additional amount of 2 g of ALA per day increased PSA by 0.10 ng/mL, but the confidence interval ranged from -0.02 to 0.22 ng per mL and included no effect. Therefore, more studies are needed to establish whether or not ALA intake has a clinically significant effect on PSA or prostate cancer. (Authors abstract)
This is a free article, click below to view:
Link to Full Text