Fish
oil contains both docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA),
while some nuts (English walnuts) and vegetable oils (canola, soybean,
flaxseed/linseed, olive) contain alpha-linolenic acid (ALA).
There
is evidence from multiple studies supporting intake of recommended amounts of
DHA and EPA in the form of dietary fish or fish oil supplements lowers
triglycerides, reduces the risk of death, heart attack, dangerous abnormal heart
rhythms, and strokes in people with known cardiovascular disease, slows the
buildup of atherosclerotic plaques ("hardening of the arteries"), and
lowers blood pressure slightly. However, high doses may have harmful effects,
such as an increased risk of bleeding. Although similar benefits are proposed
for alpha-linolenic acid, scientific evidence is less compelling, and beneficial
effects may be less pronounced.
