The role of omega 3 fatty acids on health is a hot
topic. A Medline search of keywords 'omega 3 fatty
acids and health' yielded 527 abstracts on the subject
and a Google search yielded over a million results.
Despite all of this interest, the exact role of omega 3
fatty acids, or omega 3s for short, in human health
has not yet been clearly defined. In fact, there have
been studies yielding conflicting results regarding the
actual health
benefits of these essential fatty acids. The strongest
positive link thus far has been between omega 3s and
their ability to reduce the risk of coronary heart
disease. There is also mounting evidence that
omega 3s play an important role in brain development
and function, reducing inflammation, and decreasing
the risk of certain chronic diseases. Omega 3s may
play a role in a variety of health problems including
asthma, osteoporosis, mood disorders, skin
disorders, infertility, certain types of cancer, and vision
loss, to name a few. A comprehensive review of the
current literature is beyond the scope of this article,
but we will cover some of the less controversial
findings.
Omega 3 fatty acids are a family of poly-unsaturated
fatty acids, or PUFAs, that are essential to human
health and are thought to have anti-inflammatory
properties. There are three major types of omega 3
fatty acids: eicosapentaenoic acid (EPA),
docosahexaenoic acid (DHA), and alpha-linolenic acid
(ALA). Since our bodies are unable to manufacture
omega 3s, we must obtain them from our diet, thus
the term essential fatty acids.
Omega 6 fatty acids are also essential fatty acids, but,
unlike omega 3s, these fatty acids seem to have a pro-
inflammatory effect. There is research indicating a
relationship between good health and the ratio
between omega 3 and omega 6 in our diet. Ideally,
the ratio of omega 3s to omega 6s in our diet ought to
be between 1:1 and 1:4. However, the typical
American diet is so deficient in omega 3s that the ratio
is closer to 1:20 to 1:30. Researchers believe that this
imbalance is associated with a significant rise in
inflammatory disorders such as heart disease and
arthritis in America.
Omega 3s play a beneficial role in the prevention and
treatment of heart disease. Specifically, omega 3s
decrease the risk of
arrhythmias (which can lead to sudden cardiac death),
decrease triglyceride levels, produce a slight
decrease in blood pressure, and decrease the growth
rate of atherosclerotic plaque. If you do not have heart
disease, the American Heart Association (AHA)
recommends that you consume a variety of fatty fish
such as wild salmon, mackerel, sardines, anchovies,
or tuna at least twice a week and include oils and
foods rich in alpha-linolenic acid such as flaxseed,
canola oil and walnuts. If you have been
diagnosed
with coronary heart disease, the AHA recommends
that you consume 1 g of EPA+DHA per day, preferably
from fatty fish. Alternatively, you could take EPA+DHA
in capsule form with your physician's
recommendation. If your triglycerides are high, they
suggest you take 2 to 4 grams of
EPA+DHA as capsules per day under your physician's
care. Studies have found a 20% to 45% reduction in
triglycerides and up to a 40% decrease in VLDL
cholesterol with a dose of
4 grams per day of fish oil, but this impressive finding
was accompanied, unfortunately, by a 5% to 10%
increase in LDL (bad cholesterol). This dose of
omega 3 is considered to be a high dose and should
only be taken with physician supervision. In addition
to reducing triglycerides and VLDL, omega 3s can
also reduce blood pressure in hypertensive
individuals. Data suggest that DHA is more effective
at lowering blood pressure than EPA. This effect
seems to be modest and requires a high dose of
omega 3 fatty acids. In other words, if your BP is high,
this is not the best way to lower blood pressure.
Omega-3 fatty acids may play a role in reducing the
risk of stroke. Population-based studies suggest that
the consumption of omega 3s, especially from fatty
fish, may prevent strokes caused by plaque buildup
and blood clots in arteries leading to the brain. By
eating at least two servings of fish per week, you can
reduce your risk of stroke by 50%. There is some
indication that people who consume more than 3
grams of omega 3s per day, or 3 servings of fish per
day, may be at increased risk for hemorrhagic stroke
(a potentially lethal type of stroke in which an artery in
the brain ruptures or leaks).
If you are struggling with your weight, adding fish rich
in omega-3 fatty acids to your diet and maintaining a
routine of regular physical activity may help you
achieve better control of your blood sugar and
triglyceride levels. While omega 3s don't directly
promote weight loss, these essential fatty acids may
help you improve your overall health and lower your
risk of heart disease.
Omega-3 fatty acids can be beneficial for people with
inflammatory conditions such as rheumatoid arthritis.
These essential fatty acids may reduce joint
tenderness and decrease morning stiffness. In
laboratory studies, omega-3 fatty acids have been
found to decrease inflammation and reduce the
activity of enzymes that destroy cartilage. More
research is needed to determine if omega
3s are beneficial for people with osteoarthritis.
There is some research suggesting that EPA may
play a role in the prevention and treatment of
osteoporosis. In a study of women with osteoporosis
who were over 65, those given EPA and GLA (an
omega 6 fatty acid) supplements experienced
significantly less bone loss over 3 years than subjects
who were given a placebo. Interestingly, many of
these women also experienced an increase in bone
density. To date there is no published research
assessing the effects of omega 3s on the risk of
fractures.
Last but not least, omega 3 fatty acids may play a role
in the prevention and treatment of mood disorders
such as depression and bipolar disorder. While the
jury is not completely in and there is no current
evidence suggesting that omega 3s should be used
as monotherapy (without other medications), there is
enough promising research indicating that they can
be safely used in combination with other
medications. Omega 3s can have mild anti-
depressant or mood-stabilizing effects. More
research is needed before any conclusions can be
definitively drawn regarding the role of omega 3s in
the treatment of mood disorders.
In sum, omega 3 fatty acids are naturally occurring
substances that our bodies are unable to
manufacture. The best way to get omega 3s is by
eating wild fish not likely to be contaminated by
mercury or PCBs or by taking fish oil capsules,
although the latter is more controversial. In general, a
dose of 1 gram per day of fish oil, along with vitamin C
and vitamin E supplements to prevent oxidization of
the fatty acids, is considered safe for most people.
There
are some vegetarian options, such as oil from certain
algae. There is strong evidence that omega 3s can
help prevent and treat coronary heart disease. These
essential fatty acids also likely offer other health
benefits, such as reducing symptoms of rheumatoid
arthritis, depression, and bipolar disorder, to name a
few. Like medications, there are potential side effects
associated with the use of omega 3s, especially at
doses above 3 grams per day. Consult with your
physician first if you are thinking
about adding omega 3 fatty acids.
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