Fish, Long-Chain Omega-3 Polyunsaturated Fatty Acids and Prevention of Cardiovascular Disease—Eat Fish or Take Fish Oil Supplement?
Section snippets
The ω-3 and ω-6 fatty acids
The effects of individual fatty acids on biochemical and physiological functions are determined by a combination of chain length, the number and placement of double bonds, and isomerism around these bonds. ω-3 and ω-6 fatty acids, depending on the location of the first double bond, are 2 major groups of polyunsaturated fatty acids. Linoleic acid (LA, 18:2 ω-6) and α-linolenic acid (ALA, 18:3 ω-3) are 2 essential fatty acids to humans because only algae and some fungi are able to form these
LCn3PUFAs, fish, and CVD risk factors
A large body of evidence supports that fish consumption or LCn3PUFA intake may provide cardioprotective effects.17, 18, 19 A beneficial effect of fish consumption or LCn3PUFA intake on CVD has been suggested to be related to the overall favorable effects on lipid profiles,20, 21, 22, 23 threshold for arrhythmias,24, 25 platelet activity,26, 27, 28 inflammation and endothelial function,29, 30, 31 atherosclerosis,32, 33 and hypertension.34
Fish and coronary heart disease
The hypothesis that fish consumption may reduce risk of CHD has been examined in various populations. A few case-control studies have been published,95, 96, 97, 98 and three95, 96, 97 of 4 reported a significant inverse association between fish consumption and CHD (Table 1A). The results from prospective cohort studies have been inconsistent: some studies showed a significant inverse association between fish and CHD,99, 100, 101, 102, 103, 104, 105, 106 whereas others found no significant
Fish and stroke
Strokes are generally classified into 2 groups: ischemic stroke and hemorrhagic stroke. The etiologies of these 2 types of stroke are entirely different. Because of the potential antiplatelet aggregation property of LCn3PUFAs, it was hypothesized that fish consumption may be inversely associated with ischemic stroke but not with hemorrhagic stroke.2, 4 The observation of high incidence of hemorrhage in Eskimos, who consume large amounts of fish, has raised concerns about possible adverse
Eating fish or taking fish oil supplements?
The beneficial effects of fish consumption on CVD, particularly fatal CHD, have been increasingly recognized.17, 19 Long-chain ω-3 polyunsaturated fatty acids including EPA and DHA have been suggested to be the key nutrients in fish responsible for its favorable effects. Although the findings from previous studies are inconsistent, the accumulated evidence to date is generally in favor of the beneficial effects of fish consumption in reducing risk of CVD. However, several issues merit being
Summary
Numerous experimental and observational studies have examined fish consumption and LCn3PUFA intake in relation to CVD risk. The inconsistent results may be explained by the study variations in sample size, follow-up period, dose of LCn3PUFAs used, dietary assessment method, and measurement of the health end points, etc. Nevertheless, the cumulative evidence is generally in favor of the beneficial effects of fish consumption in reducing risk of CVD, particularly fatal CHD. Although the
Statement of Conflict of Interest
All authors declare that there are no conflicts of interest.
Acknowledgments
The author thanks Dr. Pengcheng Xun for his help with the preparation for the manuscript.
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Statement of Conflict of Interest: see page 110.
This work was supported in part by the UNC-CH IBM junior faculty award.