Dietary alpha-linolenic acid is associated with reduced risk of fatal coronary heart disease, but increased prostate cancer risk: a meta-analysis.
The objective of this meta-analysis was to estimate quantitatively the associations between intake of alpha-linolenic acid [ALA, the (n-3) fatty acid in vegetable oils], mortality from heart disease, and the occurrence of prostate cancer in observational studies. We identified 5 prospective cohort studies that reported intake of ALA and mortality from heart disease. We also reviewed data from 3 clinical trials on ALA intake and heart disease. In addition, we identified 9 cohort and case-control studies that reported on the association between ALA intake or blood levels and incidence or prevalence of prostate cancer. We combined risk estimates across studies using a random-effects model. High ALA intake was associated with reduced risk of fatal heart disease in prospective cohort studies (combined relative risk 0.79, 95% CI 0.60-1.04). Three open-label trials also indicated that ALA may protect against heart disease. However, epidemiologic studies also showed an increased risk of prostate cancer in men with a high intake or blood level of ALA (combined relative risk 1.70; 95% CI 1.12-2.58). This meta-analysis shows that consumption of ALA might reduce heart disease mortality. However, the association between high intake of ALA and prostate cancer is of concern and warrants further study.
Brouwer
Ingeborg A
IA
Wageningen Centre for Food Sciences, Wageningen, the Netherlands. ingeborg.brouwer@wur.nl
Katan
Martijn B
MB
Zock
Peter L
PL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002986:Clinical Trials as Topic; D015331:Cohort Studies; D003327:Coronary Disease / Q000401:mortality* / Q000517:prevention & control; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D006801:Humans; D016239:MEDLINE; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors; D017962:alpha-Linolenic Acid / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood
D004042:Dietary Fats, Unsaturated; D017962:alpha-Linolenic Acid