Omega-3: The Good Fat
Doctors may tell you to cut the fat, but not all fats are
unhealthy. Omega-3 fatty acids may have far-reaching health benefits.
Studies suggest they help lower the risk of heart disease, the nation’s
top killer. They may also protect against depression, dementia, cancer,
and arthritis. Omega-3s are found in salmon, walnuts, spinach, and more –
but the health benefits can differ greatly from one source to another.
The Omega-3 Alphabet
Omega-3 fatty acids come in more than one form. The types found in
fish, called DHA and EPA, have been studied most extensively and appear
to have the strongest health benefits. Another form known as ALA is
found in vegetable oils, flaxseed, walnuts, and dark leafy vegetables
such as spinach. The body converts a small amount of ALA into EPA and
DHA. ALA may also have some health benefits of its own.
How Omega-3 Fights Disease
Omega-3 fatty acids help fight disease by reducing inflammation in
the blood vessels, joints, and elsewhere in the body. At high doses they
also lower the risk for an abnormal heart rhythm and reduce unhealthy
fats in the bloodstream known as triglycerides. Finally, they can slow
plaque build-up inside the blood vessels. Our bodies can’t make
omega-3s, so we must get them from foods or supplements.
Omega-3 and Heart Disease
If you've had a heart attack, a prescription dose of omega-3s may
help protect your heart. Some studies show fewer heart attacks and fewer
heart disease deaths among survivors who boosted their levels of
omega-3. The American Heart Association recommends 1 gram a day of EPA
plus DHA for people with heart disease. Eating fish is best, but your
doctor might recommend a fish oil capsule.
Omega-3 and Arrhythmias
Omega-3s seem to have a stabilizing effect on the heart. They can
lower heart rate and reduce the risk of life-threatening arrhythmias or
abnormal heart rhythms. Several common sources of omega-3s are shown
here: fish, walnuts, broccoli, and edamame, green soy beans that are
often steamed and served in the pod.
Omega-3 and Triglycerides
Omega-3s can lower your triglycerides, a blood fat that’s linked to
heart disease. Talk with your doctor before taking omega-3 supplements,
because some types can make your "bad" cholesterol worse. You can also
bring down triglyceride levels with exercise, by drinking less alcohol,
and cutting back on sweets and refined carbohydrates.
Omega-3 and High Blood Pressure
There’s strong evidence that omega-3s lower blood pressure. The
effect is small, though. One dietary strategy is to replace red meat
with fish during some meals. But it’s best to avoid salty fish, such as
smoked salmon. If you have high blood pressure, limiting salt, regular
exercise, and medications, as recommended by your doctor, can help.
Omega-3 and Stroke
The evidence is mixed on whether omega-3 supplements can help
prevent strokes. It curbs plaque build-up inside blood vessels and has
anti-clotting effects, so it may help prevent the type caused by clots
or a blocked artery. At high doses, omega-3 supplements might raise the
risk of the less common type of stroke that involves bleeding in the
brain.
Omega-3 and Rheumatoid Arthritis
Studies suggest omega-3s can reduce symptoms such as joint pain and
stiffness in people with rheumatoid arthritis. A diet high in omega-3s
may also boost the effectiveness of anti-inflammatory drugs.
Omega-3 and Depression
Omega-3 fatty acids may help smooth out mood disorders and make
antidepressants more effective. However, results of studies have been
mixed so far. Countries with higher levels of omega-3 in the typical
diet have lower levels of depression. Although more studies are needed,
the evidence so far is promising.
Omega-3 and ADHD
Some studies suggest omega-3 supplements may ease the symptoms of
attention deficit hyperactivity disorder (ADHD). We know omega-3 fatty
acids are important in brain development and function. Although evidence
isn't conclusive and a diet supplement can't offer a cure-all for ADHD,
omega-3s may provide some added benefits to traditional treatment.
Omega-3 and Dementia
The jury is still out, but there's some evidence that omega-3s may
protect against dementia and improve mental function. In one study,
older people with a diet high in omega-3 fatty acids had a lower risk of
developing Alzheimer's disease. More research is necessary to confirm
the link.
Omega-3 and Cancer
Omega-3s may help reduce the risk of colon cancer, breast cancer,
and advanced prostate cancer, but more research is needed. The American
Cancer Society recommends a diet that includes fish, but the
organization stops short of endorsing omega-3 supplements for cancer
prevention.
Omega-3 and Children
Be wary of promises that omega-3s have "brain-boosting" powers for
children. The Federal Trade Commission asked supplement companies to
stop that claim unless they can prove it scientifically. The American
Academy of Pediatrics does recommend that kids eat more fish, as long as
it's not breaded and fried. Pediatricians also caution against types of
fish that are high in mercury, such as shark, swordfish, king mackerel,
and tilefish.
Omega-3: Catch of the Day
The best source of omega-3 fatty acids is fish, though some
varieties deliver a higher dose than others. Top choices are salmon,
mackerel, herring, lake trout, sardines, anchovies, and tuna. The
American Heart Association recommends at least two servings a week of
fish, which is 3.5 ounces of cooked fish or ¾ cup of flaked fish.
Omega-3 and Tuna
Tuna is an old-school staple in many people's pantries that can be a
good source of omega-3. Albacore tuna (often labeled "white") has more
omega-3 than canned light tuna, but it also has a higher concentration
of mercury contamination. The amount of omega-3 in a fresh tuna steak
varies, depending on the species.
Dangers of Contaminated Fish
For most people, mercury in fish is not a health concern. But the
FDA has this advice for pregnant women, nursing mothers, and young
children:
- Limit albacore tuna to 6 ounces/week.
- Limit fish lower in mercury to 12 ounces/week.
- Avoid shark, swordfish, king mackerel, tilefish.
- Remove skin and fat before cooking fish.
Omega-3 Supplements
If you don’t like fish, you can get omega-3 from supplements. One
gram per day is recommended for people with heart disease, but ask your
doctor before starting. High doses can interfere with some medicines or
increase the risk of bleeding. You may notice a fishy taste and fish
burps. Read the label to find the amounts of EPA, DHA, or ALA you want
-- amounts can vary greatly.
Omega-3 for Vegetarians
If you don't eat fish or fish oil, you can get a dose of DHA from
algae supplements. Algae that is commercially grown is generally
considered safe, though blue-green algae in the wild can contain toxins.
Vegetarians also can get the ALA version of omega-3 from foods such as
canola oil, flaxseed, walnuts, broccoli, and spinach -- or products
fortified with omega-3s.
Avoiding the Omega-3 Hype
Many food products now boast that they have added omega-3 to
support various aspects of your health. But be aware that the amount of
omega-3 they contain may be minimal. They may contain the ALA form of
omega-3, which hasn't yet shown the same health benefits as EPA and DHA.
For a measured dose of omega-3, taking fish oil supplements may be
more reliable.
Omega 6: The Other Healthy Fat
There's another healthy fat known as omega-6. Research suggests it
may protect against heart disease, especially when eaten in place of
less healthy fats. The AHA recommends getting up to 10% of your total
daily calories from omega-6 fats, which are found in vegetable oils and
nuts. And now for some good news -- most Americans already get enough
omega-6 in their diet, thanks to cooking oils and salad dressings.
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