Docosahexaentanoic Acid (DHA)

Years ago, researchers studying the Greenland Eskimos noted that they had extremely low rates of cardiovascular disease, despite their high-fat, very low-carbohydrate diets. Researchers linked this seeming paradox to their high intake of fish oils, are rich in the omega-3 fatty acids EPA (eicosapentaenoic acid, or 20:5w3) and DHA (docosahexaenoic acid, or 22:6w3).  Years of careful prospective epidemiology and controlled trials have now confirmed the heart-healthy benefits of these “good fats.”

The New Omega-3 Story

For many years, it was believed that the main heart-health benefits of fish oils came from the

EPA, due to EPA’s role in modulating a class of local cellular “hormones” called eicosanoids.  Because of this, typical omega-3 fish oil product is usually biased toward higher concentrations of EPA and less DHA. The common thinking on the different functions of the different omega-3s was: EPA for the heart, DHA for the brain.

But recently, evidence has begun to accumulate to show that DHA offers greater cardiovascular benefits than EPA. In a study of 1 871 middle-aged Finnish men, it was found that men whose serum levels of DHA (and DPA) were in the highest fifth were 44% less likely to suffer a heart attack or acute chest pain attack as compared with those in the lowest fifth – yet there was no association with EPA. (Importantly, this study further found that men with high serum DHA and DPA who were also in the lowest fifth for hair mercury levels enjoyed a whopping 67% lower risk – a crucial finding, considering the high levels of heavy metals found in many fish and fish oil supplements). Another study found that Mediterranean men with coronary artery disease had significantly lower total omega-3s in their red blood cells than men free of disease – and that DHA and DPA, rather than EPA, accounted for most of the difference.

Experimental studies and clinical trials are beginning to tease out the reasons behind DHA’s greater cardiovascular benefits. Head-to-head comparisons have found that lower concentrations of DHA are needed to prevent arrhythmia – the deadly loss of the regulated drum of the heartbeat. And DHA is more effective at boosting ‘good’ HDL cholesterol and at bringing down triglycerides, a second kind of fat in the blood that poses its own risks and is especially associated with insulin resistance and metabolic syndrome X. Plus DHA exerts more powerful benefits for regulating healthy blood pressure than the same amount of EPA can manage.

Biological Impact of DHA, EPA

Experimental and clinical results are now confirming that EPA and DHA play different roles in body functions.  EPA seems to exert its activity on the cardiovascular system by suppression of arachidonic acid and series-2 (“bad”) eicosanoids.  The protective effects of DHA may lie in its ability to suppress the negative effects of cytokines (immune cell regulators) on the blood vessels, and possibly its impact on mitochondrial function. Of the two, DHA is harder for your body to make, and is more flexible in its ability to respond to the body’s needs. In times of need, it is rather difficult for EPA to convert into DHA, while DHA can be retroconverted to EPA as needed. This makes regular DHA intake – from diet or supplements –  essential to maintaining high levels in the body.

Pregnancy and Growth

The most important period in supplying adequate DHA is during the first three months before conception.  This is an important time for cell commitment and growth.  Because of its importance in nourishing the developing brain retina, DHA in the maternal diet is a factor in birth weight of newborns.  The fatty acids found in mother’s milk contain 0.2% DHA.  It is for this reason that infants fed breast milk are healthier and have better visual acuity.

Purity

Max DHA is a special molecular distillate of fish oil that provides super concentrated amounts of DHA along with EPA.  This molecular distillation process allows for the removal of heavy metals as mercury, organochlorine contaminants such as polychlorinated biphenyls (PCBs), and chemical solvents. Max DHA is also an uniquely stable fish oil, both because of its pharmaceutical-quality, ultra-low peroxide value raw material and because of the unique blend of synergistic fat-soluble antioxidants. Studies show that stable fish oil has superior impact on cardiovascular risk factors as compared with common commercial grades.

References

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Rissanen T, Voutilainen S, Nyyssonen K, Lakka TA, Salonen JT. Fish oil-derived fatty acids, docosahexaenoic acid and docosapentaenoic acid, and the risk of acute coronary events: the Kuopio ischaemic heart disease risk factor study. Circulation. 2000 Nov 28; 102(22): 2677-9.

Mori TA, Bao DQ, Burke V, Puddey IB, Beilin LJ. Docosahexaenoic acid but not eicosapentaenoic acid lowers ambulatory blood pressure and heart rate in humans. Hypertension. 1999 Aug;34(2):253-60.

Buckley R, Shewring B, Turner R, Yaqoob P, Minihane AM. Circulating triacylglycerol and apoE levels in response to EPA and docosahexaenoic acid supplementation in adult human subjects. Br J Nutr. 2004 Sep;92(3):477-83.

Paganelli F, Maixent JM, Duran MJ, Parhizgar R, Pieroni G, Sennoune S. Altered erythrocyte n-3 fatty acids in Mediterranean patients with coronary artery disease. Int J Cardiol. 2001 Mar; 78(1): 27-32.

De Caterina R, Bernini W, Carluccio MA, Liao JK, Libby P. Structural requirements for inhibition of cytokine-induced endothelial activation by unsaturated fatty acids. J Lipid Res. 1998 May; 39(5): 1062-70.