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Fish
oil isn't for everyone
May 11, 2006
Suzanne Havala Hobbs
If
a little bit of fish is good for your heart, does it follow
that a whole lot of fish oil is even better?
Some people are sold on the idea. In fact, consumers spent
more than $190 million on fish oil supplements in 2003, according
to the Nutrition Business Journal.
Fish oil is rich in omega-3 fatty acids, which some studies
have shown may help prevent heart attacks. Fatty fish such
as mackerel, lake trout, herring, sardines, tuna and salmon
are examples of fish high in beneficial omega-3s.
But contrary to popular belief, fish oil supplements aren’t
for everyone. In fact, they should only be taken by certain
individuals and, even then, only under a doctor’s supervision.
Why? Because conclusive evidence isn’t in yet.
Results of randomized clinical trials have found that supplements
of omega-3 fatty acids can lower the risk of heart attack
and stroke and slow the progression of coronary artery disease
in people with pre-existing disease. But more information
is needed to confirm these findings and better understand
how omega-3s work.
Besides, like most other nutritional supplements, fish oil
pills carry their own risks and drawbacks:
* Excessive bleeding. Concentrated doses of omega-3s can increase
the risk of hemorrhagic stroke and exacerbate health risks
for people with bleeding disorders, uncontrolled high blood
pressure and people taking anticoagulant medications.
* Anti-inflammatory effect. Reducing the body’s inflammatory
response may be a good thing for people with inflammatory
diseases such as arthritis. But people with weakened immune
systems – including many older adults, people with HIV/AIDS
and anyone on chemotherapy – could further diminish
their body’s ability to fight infections by taking large
amounts of omega-3s.
* We don’t know what the right dose is. Three grams
of omega-3 fatty acids per day is currently considered high,
but more research is needed to get a better fix on what the
right therapeutic dose is under various conditions.
* They can make you feel bad. Fish oil supplements can cause
belching, diarrhea, nausea, and an icky taste in the mouth.
On a positive note: Concerns about mercury and PCB contamination
found widely in whole fish don’t seem to be a problem
for purified commercial supplements, which recent lab tests
have found to be free of contaminants.
So who may benefit from fish oil supplements?
People with documented coronary artery disease or elevated
triglyceride levels may be helped by taking fish oil supplements,
but the American Heart Association warns that those individuals
should do so under a physician’s guidance.
Then there’s the rest of us.
Most healthy people should count on getting omega-3s –
and other needed nutrients – from whole foods. Tofu
and other soyfoods, canola oil, flaxseeds and walnuts contain
alpha-linolenic acids, which the body can convert into omega-3
fatty acids. Even fatty fish rich in omega-3s may contain
other nutrients that support health and are not found in supplements.
The American Heart Association recommends two servings of
fish per week. But many fish are now contaminated with significant
loads of mercury and cancer-causing PCBs. Children and women
in their childbearing years are the most vulnerable. So fish
eaters should limit their intake to two weekly servings and
get their omega-3s from a mix of both fish and plant sources.
For more information about choosing fish, see my previous
columns at http://www.onthetable.net/tuna_mercury.html
and http://www.onthetable.net/mercury_fish.html.
And remember: As always, most of us would do best by taking
the money we’d spend on supplements and investing it
instead in whole foods that provide a full array of health-supporting
nutrients in amounts that occur naturally.
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