A prospective study of plasma fish oil levels and incidence of myocardial infarction in U.S. male physicians.
OBJECTIVE
This study evaluated whether increased intake of fish oils (eicosapentaenoic and docosahexaenoic acids) might reduce the risk of coronary heart disease.


BACKGROUND
Observational and clinical studies have suggested that increased intake of fish oils, as reflected in plasma levels of fish oils, may reduce the risk of myocardial infarction.


METHODS
A nested case-control study was conducted among the 14,916 participants in the Physicians' Health Study with a sample of plasma before randomization. Each participant with myocardial infarction occurring during the first 5 years of follow-up was matched by smoking status and age with a randomly chosen control participant who had not developed coronary heart disease.


RESULTS
Mean levels of fish oils (with 95% confidence interval [CI] for paired differences and p values) in case and control participants, expressed as percent of total fatty acids, were, for eicosapentaenoic acid, 0.26 versus 0.25 (95% CI -0.03 to 0.05, p = 0.70) in cholesterol esters and 0.56 versus 0.54 (95% CI -0.04 to 0.09, p = 0.44) in phospholipids, and for docosahexaenoic acid, 0.23 versus 0.24 (95% CI -0.07 to 0.04, p = 0.64) in cholesterol esters and 2.22 versus 2.14 (95% CI -0.10 to 0.27, p = 0.36) in phospholipids. Results adjusted for major cardiovascular risk factors showed a very similar lack of association between fish oil levels and the incidence of myocardial infarction.


CONCLUSIONS
These results indicate no beneficial effect of increased fish oil consumption on the incidence of a first myocardial infarction. However, the effect of very high levels of fish oils could not be evaluated.
Guallar
E
E
Division of Preventive Medicine, Brigham and Women's Hospital, Boston Massachusetts.
Hennekens
C H
CH
Sacks
F M
FM
Willett
W C
WC
Stampfer
M J
MJ
D000276:Adjuvants, Immunologic / Q000627:therapeutic use; D001241:Aspirin / Q000627:therapeutic use; D002338:Carotenoids / Q000627:therapeutic use; D016022:Case-Control Studies; D002788:Cholesterol Esters / Q000097:blood; D004311:Double-Blind Method; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000097:blood*; D005395:Fish Oils / Q000008:administration & dosage / Q000097:blood*; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000453:epidemiology* / Q000517:prevention & control; D010743:Phospholipids / Q000097:blood; D010820:Physicians; D011446:Prospective Studies; D012307:Risk Factors; D019207:beta Carotene
D000276:Adjuvants, Immunologic; D002788:Cholesterol Esters; D015525:Fatty Acids, Omega-3; D005395:Fish Oils; D010743:Phospholipids; D019207:beta Carotene; D002338:Carotenoids; D001241:Aspirin