Omega-3 fatty acids in health and disease and in growth and development

Abstract

Several sources of information suggest that man evolved on a diet with a ratio of omega 6 to omega 3 fatty acids of approximately 1 whereas today this ratio is approximately 10:1 to 20-25:1, indicating that Western diets are deficient in omega 3 fatty acids compared with the diet on which humans evolved and their genetic patterns were established. Omega-3 fatty acids increase bleeding time; decrease platelet aggregation, blood viscosity, and fibrinogen; and increase erythrocyte deformability, thus decreasing the tendency to thrombus formation. In no clinical trial, including coronary artery graft surgery, has there been any evidence of increased blood loss due to ingestion of omega 3 fatty acids. Many studies show that the effects of omega 3 fatty acids on serum lipids depend on the type of patient and whether the amount of saturated fatty acids in the diet is held constant. In patients with hyperlipidemia, omega 3 fatty acids decrease low-density-lipoprotein (LDL) cholesterol if the saturated fatty acid content is decreased, otherwise there is a slight increase, but at high doses (32 g) they lower LDL cholesterol; furthermore, they consistently lower serum triglycerides in normal subjects and in patients with hypertriglyceridemia whereas the effect on high-density lipoprotein (HDL) varies from no effect to slight increases. The discrepancies between animal and human studies most likely are due to differences between animal and human metabolism. In clinical trials eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the form of fish oils along with antirheumatic drugs improve joint pain in patients with rheumatoid arthritis; have a beneficial effect in patients with ulcerative colitis; and in combination with drugs, improve the skin lesions, lower the hyperlipidemia from etretinates, and decrease the toxicity of cyclosporin in patients with psoriasis. In various animal models omega 3 fatty acids decrease the number and size of tumors and increase the time elapsed before appearance of tumors. Studies with nonhuman primates and human newborns indicate that DHA is essential for the normal functional development of the retina and brain, particularly in premature infants. Because omega 3 fatty acids are essential in growth and development throughout the life cycle, they should be included in the diets of all humans. Omega-3 and omega 6 fatty acids are not interconvertible in the human body and are important components of practically all cell membranes. Whereas cellular proteins are genetically determined, the polyunsaturated fatty acid (PUFA) composition of cell membranes is to a great extent dependent on the dietary intake.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of dietary fatty acids on expression of lipogenic enzymes and fatty acid profile in tissues of bulls

“…In countries with the Mediterranean diet (low content of SFA and high content of MUFA) the incidence of coronary heart disease is much lower when compared with the countries with the diets which are high in SFA (Lada and Rudel, 2003). The particular health benefit has been linked to n-3 PUFA which are essential for normal growth and development (Simopoulos, 1991). Long chain n-3 PUFA (docosahexaenoic acid and eicosapentaenoic acid) demonstrated anti-atherogenic, anti-thrombotic, antiinflammatory and immunosuppressive properties in experimental studies in man (Williams, 2000;Garg et al, 2006).…”

Administration of low doses of fish oil derived N-3 fatty acids to elderly subjects

“…A modi®ed milk formula was designed to provide low amounts of ®sh oil, which might have a bene®cial effect in cardiovascular disease and other diseases common among elderly people (Kinsella et al, 1990;Simopoulos, 1991). In addition, the formula also provided essential nutrients for elderly subjects, such as minerals and vitamins.…”

“…Other nutritional components supplied by 100 g of powder were: 29 g of protein, 48 g of carbohydrates, 0.46 g of lecithin, 7.57 mg of a-tocopherol, and also calcium as calcium phosphate, magnesium, sodium, vitamins C, B 6 , B 9 , B 12 , A and D, arti®cial¯avours and asparthame. Calcium and magnesium were added as preventives against bone loss and muscular degenerative diseases (Polley et al, 1987;Smith et al, 1989). Daily ingestion of 1000 ml of the dietary product provided 100% of the recommended dietary allowances (RDA) (NRC, 1989) for minerals and vitamins.…”

“…Since this observation was made, a number of studies have con®rmed the bene®cial effect of n-3 PUFA in the prevention of cardiovascular disease (Kromhout et al, 1985;Leaf & Weber, 1988). These fatty acids appear to modulate eicosapentaenoic metabolism and lower serum triglycerides, and thus may have potential for the amelioration of atherogenesis and thrombosis (Kinsella et al, 1990;Simopoulos, 1991). In addition, other bene®cial effects have been described for n-3 PUFA in the treatment of arthritis, psoriasis, lupus, cancer and diabetes (Simopoulos, 1991), which are common diseases in elderly people.…”

n-3 Polyunsaturated fatty acids decrease mucosal/epidermal reactions and enhance antitumour effect of ionising radiation with inhibition of tumour angiogenesis

“…The n-3 polyunsaturated fatty acids (PUFAs), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are present at high concentrations in some fish oils, have attracted interest because of their importance in normal development (Neuringer et al, 1988), and for their role as dietary supplements in the prevention and treatment of chronic cardiovascular disease (Simopoulos, 1991), the treatment of arthritic disorders (Kremer, 1991) and diabetes mellitus (Malasanos and Stacpoole, 1991). These agents have been evaluated in various clinical trials in which they have proved to be safe and well tolerated.…”