Abstract

The dietary deficiency of docosahexaenoic acid (DHA) is associated with a variety of human diseases, such as brain disorders and infertility. Because of the capacity to convert DHA precursors, such as α-linolenic acid, to DHA is very limited in the human tissues and the brain, it has to be supplied in the diet. A great number of both in vivo and in vitro investigations have shown pharmacological and nutritional effects of DHA and its metabolites in animal tests and experiments at cell level, but limited documents discussed on how and why DHA can or cannot reach the target tissues to alleviate disorders after oral administration. A pure DHA intake in the form of a free fatty acid causes gastrointestinal complains. On the other hand, free DHA is unstable to oxidation and also difficult to be incorporated into delivering vehicles. Generally, DHA can be transported into tissues and the brain via plasma vehicle, and the major DHA carriers used in dietary supplements are phospholipids (PLs) and triglycerides (TGs). In the present paper, the key points center around proposed mechanisms mainly on (i) how the DHA carriers can be absorbed and distributed in the delivery of DHA into human tissues and the brain, and (ii) how consumers can benefit from nutritional supplements that contain the DHA carriers, particularly in the improvement of cognitive decline and fertility. It is also expected that this review may significantly help with driving sellers and consumers into a new way to choose various DHA supplements for the human health. The article presents some promising patents on docosahexaenoic acid - containing phospholipids and triglycerides based nutritional supplements.

Keywords: Phospholipids, triglycerides, fish liver, fish oil, algae oil, krill oil, salmon roe, docosahexaenoic acid, phosphatidylserine, phosphatidylcholine, phosphatidylethanolamine, phosphatidylmonomethyl-ethanolamine, lysophosphatidyl-choline, cognitive decline, infertility, PLs, TGs, Supplements, lipid peroxidation, sperm cells, Ethyl-DHA, DHA PC, DHA-PE, EPA PC, DHA TGs, T-Soy-PS, sn-3, PC, Caco-2, LCAT, Omega-3 fatty acids, Ether Lecithin, DRI, Alzheimer's disease