The dietary fat both in its amount and composition is significantly in
volved in the development of cardiovascular diseases (CVD). Epidemiolo
gical studies have indicated a lower incidence of CVD in populations w
ith a high habitual intake of marine fish and fish oils, and this appa
rent protection may be due to the presence of n-3 far, acids in the di
etary fish. Two populations, a fish consuming one from coastal area an
d an inland one with nan-fish consuming from the Nellore district of s
outh India, were selected for the present investigation. A total of on
e thousand healthy subjects were randomly chosen (500 in each populati
on) from both sexes aged from 20 to 70 years. Blood samples were drawn
in the morning period under fasting condition and the biochemical var
iables were determined in the serum by using standard spectrophotometr
ic methods. Fatty acid composition of phospholipids was evaluated from
the serum samples of 38 subjects by gas-liquid chromatography. The co
ncentration of serum cholesterol, triacylglycerol and LDL-cholesterol
were significantly lower in the fish consumers whereas HDL-cholesterol
was higher in the fish consumers than in the non-fish consumers. The
difference between the percent quantities of the three n-3 fatty acids
(eicosapentaenoic, docosapentaenoic and docosahexaenoic acids) were h
ighly significant (p<0.001) with a greater value in fish consumers. Th
e lower atherogenecity among the fish consumers on the whole may be ex
plained due to the presence of the enriched n-3 fatty acids in their s
erum phospholipids unlike in the non-fish consumers.