Cardiovascular Benefits of Omega-3 Fats

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Cardiovascular Benefits of Omega-3 Fats

By Dr. Holub

http://www.mercola.com/2002/mar/27/omega3_fats.htm

Professor, Department of Human Biology and Nutritional Sciences, University

of Guelph, Guelph, Ont. ON N1G 2W1

During the past few years, there has been an increase in both scientific

and public interest in the role of omega-3 fatty acids found in fish and

fish oils in the prevention and management of cardiovascular disease.

The omega-3 fatty acids that are of particular interest for cardiovascular

care include EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid),

which are found predominantly in fish and fish oils.1,2,3 The basis of this

heightened interest in dietary intakes of EPA and DHA comes partly from

epidemiological and population studies4 indicating that increased

consumption of fish as a source of omega-3 fatty acids is often associated

with decreased mortality (as well as morbidity) from cardiovascular disease.

Controlled-intervention trials in humans have indicated a favorable

modifying effect of dietary fish oils on various risk factors for

cardiovascular disease independent of their lowering of blood

cholesterol.1,2,3

Dietary supplementation with encapsulated omega-3 fish oil concentrates has

shown the potential to reduce both the progression of cardiovascular

disease and related mortality, including sudden cardiac death.5,6

What Are Omega-3 Fatty Acids?

Omega-3 fatty acids are long-chain polyunsaturated fatty acids (18-22

carbon atoms in chain length) with the first of many double bonds beginning

with the third carbon atom (when counting from the methyl end of the fatty

acid molecule).

The fish-based and fish-oil-based omega-3 polyunsaturated fatty acids (also

referred to as n-3 PUFA) consist of EPA (20 carbon atoms, 5 double bonds)

and DHA (22 carbon atoms, 6 double bonds).

Whereas plant foods and vegetable oils lack EPA and DHA, some do contain

varying amounts of the n-3 PUFA alpha-linolenic acid (ALA), which has 18

carbon atoms and 3 double bonds. Many vegetable oils are greatly enriched

in omega-6 fatty acids (mainly as linoleic acid in corn, safflower,

sunflower and soybean oils), but canola oil (nonhydrogenated), ground

flaxseed and walnuts are rich sources of ALA.

The typical North American diet provides about 1-3 g of ALA per day but

only 0.10-0.15 g of EPA plus DHA per day.7,8 The very high intake of n-6

PUFA, mostly as linoleic acid (LA) in our diet (12-15 g/day) from common

vegetable oils (corn, safflower, soybean) and other sources.

The rest is here:

http://www.mercola.com/2002/mar/27/omega3_fats.htm