The biological role of fish oils and why they are essential for optimum health.
Fish oils are derived predominantly from cold water fish which have fed on other marine life such as phytoplankton. These oils, rich in omega-3 fatty acids, are excellent sources of essential eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA have multiple actions in a number of body systems including the cardiovascular, ocular and the central nervous system. In the cardiovascular system, fish oils have been shown to improve lipid parameters, lower blood pressure and inhibit platelet aggregation. Studies by Calabresi (1) and Harris have shown that as little as 1.5 grams of fish oils per day can reduce total cholesterol levels in as little as 2 weeks. The lipid lowering effect of EPA and DHA is thought to result from inhibition of hepatic liponeogenesis while stimulating β-oxidation of fatty acids.
More recently, fish oils have been shown to have beneficial effects on vision health. Omega-3 fatty acid supplementation can improve visual acuity and reduce the risk of advanced age-related macular degeneration (AMD) (2).
EPA and DHA supplementation has recently expanded to an emerging area of research: fish oils and neurotherapeutics. The brain contains about 20 percent dry weight of these polyunsaturated fatty acids. Beneficial effects of omega-3 fatty acids have been linked to a reduced risk for developing Alzheimer’s disease, ADHD, schizophrenia and more recently, major depressive disorder. Although the pathogenesis of depression remains vague, there is a growing body of evidence that links proinflammatory cytokines to depression. Proinflammatory cytokines, primarily IL-1β and TNF-α have shown to lower serum tryptophan (serotonin precursor), cause resistance to glucocorticoid hormones and alter neurotransmitter metabolism. Due to the powerful anti-inflammatory properties of fish oils, the release of these proinflammatory cytokines can be suppressed, thus helping to maintain optimal brain health.
DHA has been recently discovered as an essential nutrient for pregnant and nursing mothers. Studies have shown that fish oil supplementation, especially during the third trimester and early breast feeding period results in a higher IQ score and increased cognitive function later in life. Currently, DHA supplementation is not a required ingredient in infant formulas and must be derived from maternal sources.
There is concern that pregnancy can cause long-term effects to maternal DHA stores. Doctors believe that as much as one-third of the mother’s DHA stores can be depleted during pregnancy. It has been proposed that this depletion can increase the risk of depressive symptoms after birth. With adequate fish oil supplementation, pregnant and nursing mothers can replenish DHA stores within one year post-partum.
Conclusion:
Fish oils contain critical nutrients that aid in a number of biological systems. Taking a fish oil supplement regularly can help fill in the gaps and provide the essential fatty acids missing from our diets.
- Calabresi, L., et al. An omega-3 polyunsaturated fatty acid concentrate increases plasma high-density lipoprotein 2 cholesterol and paraoxonase levels in patients with familial combined hyperlipidemia. Metabolism. 53(2): 153-158, 2004.
- Cangemi, F. TOZAL Study: an open case control study of an oral antioxidant and omega-3 supplement for dry AMD. BMC Ophthalmology. 7:3, 2007.
