Gabe Mirkin, M.D.
The American Heart Association recommends eating at least two
servings of fish per week. Fish, particularly cold-water, fatty fish
such as salmon, mackerel, herring, sardines, trout and tuna, contain
omega-3 fatty acids that help to protect against heart disease.
Omega-3s can help prevent blood platelets from clotting and sticking
to artery walls in the form of cholesterol-rich plaques. Most heart
attacks happen when blood clots lodge in veins and arteries,
preventing blood from circulating properly. Omega-3s may also help
prevent inflammation in diseases such as rheumatoid arthritis, and
lack of omega-3s may also cause mood disorders such as post-partum
All seafood contains some, including non-fatty fish, such as
halibut, flounder, perch, trout and cod. Shrimp, lobster, clams, and
oysters also provide decent amounts of omega-3s, as do freshwater
Wild fish are not richer in omega-3 fish oils than farm-raised
varieties. Farm-raised fish such as salmon and trout won't grow
without omega-3 fatty acids in their diet, so fish farmers add it to
the fish meal. Farmed catfish and tilapia, however, do not need
omega-3 fatty acids, so these farm-raised fish have little or no
omega-3s. In the wild, fish get their omega-3s from algae, plankton
and other fish that they may eat.
You don't need to eat fish to get omega-3s. You can get omega-3s by
eating whole grains, beans, such as soybeans and seeds. Flaxseeds
are among the richest plant sources of omega-3s.
Many people avoid fish because of fear of mercury poisoning. Nearly
all fish contain some amount of methyl mercury, which theoretically
can damage nerves, particularly during fetal growth. Mercury is
released into the air by pollution. Rainwater brings it into streams
and oceans, where bacteria transform it into methyl mercury. Fish
get their dose as they feed on algae and other organisms. Older,
larger fish that eat other fish accumulate the most methyl mercury,
so big carnivores such as swordfish and tuna pose the greatest risk
to susceptible populations. Methyl mercury is stored in the flesh
and there is no way to remove it.
The Food and Drug Administration recommends that pregnant women and
women who might become pregnant, nursing mothers, and young children
not eat shark, swordfish or large tunafish. They should eat plenty of other types of fish and shellfish. If a pregnant woman chooses to avoid seafood, she should make sure she gets plenty of omega-3's from seeds such as flaxseed, or from supplements. The FDA does not recommend any limits on fish consumption for the general population.
Omega-3's from plants