P. Marckmann et M. Gronbaek, Fish consumption and coronary heart disease mortality. A systematic reviewof prospective cohort studies, EUR J CL N, 53(8), 1999, pp. 585-590
Objectives: To review all prospective cohort studies examining the relation
ship between fish intake and coronary heart disease mortality, and to asses
s the strength and consistency of their findings.
Design: Systematic review of studies based on individual records of fish or
n-3 polyunsaturated fatty acid consumption and coronary heart disease deat
h. Studies were given scientific quality scores and divided into categories
of high, intermediate, or insufficient quality.
Main outcome measure: Coronary heart disease mortality.
Results: Eleven studies were identified. The cohorts counted a total of 116
764 individuals. Of four studies judged to be of high quality, the two larg
est (n = 44895 and 20051) were performed in populations at low risk of coro
nary heart disease. They found no protective effect of fish consumption. Th
e other two high-quality studies were relatively small (n = 852 and 1822) a
nd included individuals at higher risk. They both found an inverse relation
ship between fish consumption and coronary heart disease death, suggesting
that 40-60 g fish per day is optimal and associated with a risk reduction o
f 40-60%. Results of four studies of intermediate quality support that fish
consumption is inversely associated with coronary heart disease mortality
in high-risk populations only. Three studies were judged to be of insuffici
ent quality to be used for drawing conclusions.
Conclusions: Fish consumption is not associated with reduced coronary heart
disease mortality in low-risk populations. However, fish consumption at 40
-60 g daily is associated with markedly reduced coronary heart disease mort
ality in high-risk populations. The underlying biochemical mechanism is not
known and causal inference premature.