CORRELATION BETWEEN BIOMARKERS OF OMEGA-3-FATTY-ACID CONSUMPTION AND QUESTIONNAIRE DATA IN AFRICAN-AMERICAN AND CAUSCASIAN UNITED-STATES MALES WITH AND WITHOUT PROSTATIC-CARCINOMA

Results from animal studies suggest that omega-3 fatty acids from mari ne sources are protective against cancer, To determine whether adipose tissue and erythrocyte membrane fatty acid composition could serve as biomarkers of essential fatty acid consumption in subjects with prost ate cancer, we compared fish consumption, which was estimated using a food frequency survey, to the omega-3 fatty acid content of adipose ti ssue and erythrocyte membranes. The study was conducted using 127 men who had undergone a prostate biopsy, All subjects were recruited from a university hospital urology clinic, African Americans comprised 23% of the subjects, and 70% were diagnosed with prostate cancer, We found a correlation of 0.44 with 95% confidence intervals (CIs) = 0.29-0.57 between reported fish consumption and the omega-3 fatty acid eicosape ntaenoic acid composition in erythrocyte membranes and 0.38 with 95% C I = 0.21-0.53 when the dietary survey was compared to eicosapentaenoic acid in adipose tissue. The survey/biomarker correlations in cases we re not significantly different from the correlations in controls. The study had 90% power to detect a 0.35 difference between correlations. These results suggest that the presence of prostate cancer does not af fect the adipose tissue or erythrocyte membrane biomarkers of fatty ac id consumption, and that erythrocyte membranes are as useful as biomar kers as is adipose tissue. Our findings corroborate previous studies t hat found that tissue biomarkers can reflect past fatty acid consumpti on and support the use of biomarkers in case-control studies using can cer patients.