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What’s
the difference: A Breakdown of Omega-3 Fatty Acids
Health
News
Many foods from eggs to cereal, now claim to contain the
power-house essential fatty acid known to promote heart health,
support joint health, improve emotional well-being and possibly
help protect against cancer, Alzheimer’s, and vision
problems — omega-3. Unfortunately, all that advertising
falls short considering the majority of these products contain
ALA, found in flaxseed, canola and soy, which
may not have the same benefits of DHA and
EPA, the omega-3s found in salmon, trout,
other fish, and algae that are linked to a lower risk of heart
disease.
Plant-derived alpha-linolenic acid (ALA) has been studied
in a limited number of investigations, and while some studies
suggest a potential of protection from cardiovascular disease,
this potential remains to be proven in intervention group
studies. In contrast, eicosapentaenoic acid (EPA) and docosahexaenoic
acid (DHA) have been studied in thousands of investigations
supporting evidence that these omega-3 fatty acids do in fact
reduce the chance of a heart attack and lowering blood triglyceride
levels.
So what’s the difference?
DHA (Docosahexaenoic Acid) is an omega-3 essential fatty
acid found most often in fish oil that can reduce the level
of blood triglycerides in humans, which may reduce the risk
of heart disease, and is the most abundant essential fatty
acid (polyunsaturated fatty acids, PUFAs) in the brain comprising
40%. Low levels of DHA result in the reduction of brain serotonin
levels and have been associated with ADD, ADHD, Alzheimer's
disease, and depression, among other diseases.
EPA (Eicosapentaenoic Acid) is a member of the omega-3 fatty
acid family responsible for regulating hormonal balance, immune
system function, brain function, and blood supply to tissues,
thus reducing the incidence of inflammatory diseases. EPA
is also beneficial in lowering high cholesterol and hypertension
(high blood pressure), helping prevent heart disease and stroke.
Research has shown a lack of EPA weakens the body’s
immune system, or ability to fight disease.
ALA (Alpha-linolenic acid) is the major plant omega-3 fatty
acid. Flaxseed oil is the richest natural source of this fatty
acid, but alpha-linolenic acid is also present in large amounts
in a variety of other plant oils, such as canola or soybean,
and is also found in walnuts. ALA is thought to have a major
biochemical role as the principal precursor in the body’s
formation of the long chain polyunsaturated fatty acids, EPA
and DHA - meaning the human body converts ALA into EPA and
DHA, but with great difficulty. The conversion rate is slow
and inefficient (between one and five per cent), and can be
inhibited by various conditions such as a diet high in linolenic
acid (omega-6), trans fatty acids such as fast foods and baked
goods, alcohol intake, certain health conditions, and vitamin
and mineral deficiencies (B3, B6, C, zinc, magnesium).
“The good news is that omega-3s from fish oil can reduce
the risk of heart attack, and the research is building on
other health benefits,” said Center for Science in the
Public Interest senior nutritionist David Schardt. “But
get your omega-3s from fatty fish like salmon, or take fish
oil or algal oil capsules. Many foods with omega-3 claims
have only or mostly ALA, which may not prevent anything.”
So the next time you find yourself browsing your local grocery
store aisle and read the label on a carton of eggs that does
include DHA and EPA, be aware it contains no more of those
omega-3s than the amount in one and a half teaspoons of salmon,
the richest source of omega-3s, according to CSPI. Remember
the only thing that is self-evident, or obvious, is that ALA
is simply not as effective as DHA and EPA when it comes to
benefiting your health.
SOURCES:
http://www.winomeg3complex.com
http://www.mayoclinic.com/health/fish-oil/NS_patient-fishoil
http://lansbury.bwh.harvard.edu/eicosapentaenoic_acid_reviews_L.htm
http://www.usatoday.com/news/health/painter/2007-11-11-yourhealth_N.htm
http://www.cspinet.org/new/pdf/omegas.pdf
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