The Importance of the Omega-6/Omega-3 Fatty Acid Ratio in Cardiovascular Disease and Other Chronic Diseases

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Experimental Biology and Medicine (Impact Factor: 2.23). 07/2008; 233(6):674-88. DOI: 10.3181/0711-MR-311
Source: PubMed

ABSTRACT Several sources of information suggest that human beings evolved on a diet with a ratio of omega-6 to omega-3 essential fatty acids (EFA) of approximately 1 whereas in Western diets the ratio is 15/1-16.7/1. Western diets are deficient in omega-3 fatty acids, and have excessive amounts of omega-6 fatty acids compared with the diet on which human beings evolved and their genetic patterns were established. Excessive amounts of omega-6 polyunsaturated fatty acids (PUFA) and a very high omega-6/omega-3 ratio, as is found in today's Western diets, promote the pathogenesis of many diseases, including cardiovascular disease, cancer, and inflammatory and autoimmune diseases, whereas increased levels of omega-3 PUFA (a lower omega-6/omega-3 ratio), exert suppressive effects. In the secondary prevention of cardiovascular disease, a ratio of 4/1 was associated with a 70% decrease in total mortality. A ratio of 2.5/1 reduced rectal cell proliferation in patients with colorectal cancer, whereas a ratio of 4/1 with the same amount of omega-3 PUFA had no effect. The lower omega-6/omega-3 ratio in women with breast cancer was associated with decreased risk. A ratio of 2-3/1 suppressed inflammation in patients with rheumatoid arthritis, and a ratio of 5/1 had a beneficial effect on patients with asthma, whereas a ratio of 10/1 had adverse consequences. These studies indicate that the optimal ratio may vary with the disease under consideration. This is consistent with the fact that chronic diseases are multigenic and multifactorial. Therefore, it is quite possible that the therapeutic dose of omega-3 fatty acids will depend on the degree of severity of disease resulting from the genetic predisposition. A lower ratio of omega-6/omega-3 fatty acids is more desirable in reducing the risk of many of the chronic diseases of high prevalence in Western societies, as well as in the developing countries.

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    • "Beef produced from cattle at pasture has desirable nutritional characteristics and is increasingly valued by consumers as it tends to have higher levels of polyunsaturated fatty acids (PUFAs) and lower ratios of n-3 : n-6 FAs (Schmid et al., 2006; Fincham et al., 2009; Duckett et al., 2013). Research with humans suggests that a lower ratio of n-3 : n-6 FAs is desirable for reducing the risk of many chronic diseases such as cardiovascular disease, cancer, inflammatory and autoimmune diseases (Simopoulos, 2008). Diet could influence FA profile of meat and some research indicates that feeding cattle at pasture compared with typical feedlot diets results in greater concentrations of conjugated linoleic FA (CLA) and more favorable ratio between n-6 : n-3 in beef. "
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    ABSTRACT: Thirty Aberdeen Angus crossbred steers (281 ± 16 kg) were used to test the effect of finishing feeding system on growth performance, meat quality and fatty acid (FA) profile in intramuscular fat. Steers were fed in confinement (forage:concentrate ratio of 50 : 50; DM basis) or with different levels of energy supplementation (0, 0.4, 0.8 and 1.2% BW) at pasture (Avena strigosa Schreb and Lolium multiflorum L.). There were no differences between treatments for ADG (average = 1.60 kg/day), hot carcass weight (HCW) (average = 229 kg) and subcutaneous fat depth (average = 3 mm). Dressing % (P = 0.06; tendency) and carcass ADG (P = 0.02) linearly increased with level of supplementation for pasture steers. No differences were observed between treatments for tenderness, marbling, pH, color b*, or cooking loss and drip loss in samples of Longissimus dorsi. However L* increased linearly (P = 0.05) with level of supplementation. The concentrations of myristic, palmitic, estearic and linoleic FA did not differ among treatments. The concentration of n-3 FA increased (P<0.001) in steers at pasture compared with confinement, but n-6 FA concentrations did not differ between feeding system. Supplementation up to 0.4% BW increase (P<0.001) conjugated linoleic acid (CLA) and linolenic FA concentrations in intramuscular fat when compared with confinement. The level of supplementation on pasture linearly decreased (P<0.001) n-3 and CLA and linearly increased (P = 0.001) the n-6 : n-3 ratio. Finishing of steers grazing winter pasture with energy supplementation or in confinement fed a medium-concentrate diet did not affect meat quality (tenderness, marbling, parameter b* on the CIE L*a*b* scale, cooking and drip losses) except for a* and L*. However, intramuscular fat of animals finished at pasture with moderate level of supplementation compared to animals fed in confinement had greater concentration of CLA, linolenic, and n-3, and lower n-6 : n-3 in intramuscular fat.
    animal 06/2015; 9. DOI:10.1017/S1751731115000105 · 1.78 Impact Factor
    • "Docosapentaenoic (DPA) (C22:5ω-6) and docosahexaenoic (DHA) (C22:6ω-3) acids were also detected in minor proportions. The ω-6/ω-3 ratio, which is an important determinant for reducing the risk of many chronic diseases (Simopoulos 2008), is beneficial, as their values were lower to the recommended value of 4:1 in all raw milk and cream total lipid samples (Tables 2 and 4). The hypocholesterolaemic/hypercholesterolaemic (h/H) ratio ranged from 0.50 to 0.69 in all examined samples, indicating that raw milk and cream fat have low cholesterolaemic effect. "
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    ABSTRACT: Information on fatty acid (FA) profile is critical for the production and promotion of sheep milk and derivative dairy products. The presence of the essential ω-3 and ω-6 FA in milk fat as well as other less common FA, like linoleic acid isomers, has gained an increasing interest due to the consumer demand for a healthy diet. This research assesses the FA profile and estimates the lipid quality indices (ratio between hypocholesterolaemic and hypercholesterolaemic fatty acids, peroxidisability index, atherogenic index, and thrombogenic index) of raw milk and cream fat from two indigenous Greek sheep breeds (Karagouniko and Chios) at different lactation stages. Raw milk and cream fat presented a favorable ω-6/ω-3 ratio below 4:1. Atherogenic and thrombogenic indices of all studied milk fat fluctuated in sufficiently low levels (<3). The FA profile and lipid quality indices in both raw milk and cream samples differed significantly depending more on the lactation stage compared to the breed type. Raw milk fat from late lactation had more beneficial fatty acid profile compared to early and middle lactation stages. Differences among breeds were highlighted when raw milk and cream samples were compared within the same lactation stage. Raw milk and cream fat from Karagouniko breed were characterised by higher ω-3 proportion, lower ω-6/ω-3 ratio and lower thrombogenic index value compared to those from Chios breed.
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    • "In addition, PUFA are the main components of cell membranes and PUFA composition influences cell membrane function (Abayasekara & Wathes 1999). In recent years, research has focused on decreasing the ratio of dietary n-6 to n-3 fatty acids (FA) (Bilby et al. 2006a) because of the health benefits of lower ratios (Simopoulos 2008). The regulatory roles of these two FA groups on animal reproduction and the underlying mechanisms were discussed earlier (Mattos et al. 2000; Wathes et al. 2007). "
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    ABSTRACT: The objectives of this study were to investigate the effects of dietary n-6/n-3 fatty acid (FA) ratio on digestibility, blood metabolites and FA profile of Hanwoo heifers. Fifteen Hanwoo heifers (22 ± 3 months old; 357 ± 69.7 kg) were randomly assigned to three dietary treatments with n-6/n-3 FA ratios of 2.07, 5.18 and 7.37. The animals were housed individually in digestion crates and fed total mixed rations at 2.2% of body weight for 2 weeks of adaptation and 1 week of collection. Treatment effects on in vivo digestibility, plasma metabolite and fatty acid profiles, and in vitro ruminal fermentation and fatty acid profiles were examined. In vivo digestibility was not affected (P > 0.05) by dietary n-6/n-3 FA ratio. However, in vitro dry matter digestibility and concentrations of total volatile fatty acids and propionate decreased (P < 0.05) linearly with increasing n-6/n-3 FA ratio. Plasma insulin and progesterone increased linearly (P < 0.05), but linolenic acid and total n-3 FA decreased linearly (P < 0.05) with increasing n-6/n-3 ratio. Increasing the dietary n-6/n-3 FA ratio can increase the n-6/n-3 FA ratio in plasma and ruminal fluid as well as plasma progesterone secretion. © 2015 Japanese Society of Animal Science.
    Animal Science Journal 05/2015; DOI:10.1111/asj.12401 · 1.04 Impact Factor
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