scholarly journals Fatty acids: facts vs. fiction

Author(s):  
Reinhard Waehler

Abstract. During the last 100 years official dietary guidelines have recommended an increased consumption of fats derived from seeds while decreasing the consumption of traditional fats, especially saturated fats. These recommendations are being challenged by recent studies. Furthermore, the increased use of refining processes in fat production had deleterious health effects. Today, the number of high-quality studies on fatty acids is large enough to make useful recommendations on clinical application and everyday practice. Saturated fats have many beneficial functions and palmitic acid appears to be problematic only when it is synthesized due to excess fructose consumption. Trans fatty acids were shown to be harmful when they are manmade but beneficial when of natural origin. Conjugated linoleic acid has many benefits but the isomer mix that is available in supplement form differs from its natural origin and may better be avoided. The ω3 fatty acid linolenic acid has rather limited use as an anti-inflammatory agent – a fact that is frequently overlooked. On the other hand, the targeted use of long chain ω3 fatty acids based on blood analysis has great potential to supplement or even be an alternative to various pharmacological therapies. At the same time ω6 fatty acids like linoleic acid and arachidonic acid have important physiological functions and should not be avoided but their consumption needs to be balanced with long chain ω3 fatty acids. The quality and quantity of these fats together with appropriate antioxidative protection are critical for their positive health effects.

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1816
Author(s):  
Michael F. Tlusty

Humans under-consume fish, especially species high in long-chain omega-3 fatty acids. Food-based dietary guidelines are one means for nations to encourage the consumption of healthy, nutritious food. Here, associations between dietary omega-3 consumption and food-based dietary guidelines, gross domestic product, the ranked price of fish, and the proportions of marine fish available at a national level were assessed. Minor associations were found between consumption and variables, except for food-based dietary guidelines, where calling out seafood in FBDGs did not associate with greater consumption. This relationship was explored for consumers in the United States, and it was observed that the predominant seafood they ate, shrimp, resulted in little benefit for dietary omega-3 consumption. Seafood is listed under the protein category in the U.S. Dietary Guidelines, and aggregating seafood under this category may limit a more complete understanding of its nutrient benefits beyond protein.


2006 ◽  
Vol 65 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Timothy J. Key ◽  
Paul N. Appleby ◽  
Magdalena S. Rosell

Vegetarian diets do not contain meat, poultry or fish; vegan diets further exclude dairy products and eggs. Vegetarian and vegan diets can vary widely, but the empirical evidence largely relates to the nutritional content and health effects of the average diet of well-educated vegetarians living in Western countries, together with some information on vegetarians in non-Western countries. In general, vegetarian diets provide relatively large amounts of cereals, pulses, nuts, fruits and vegetables. In terms of nutrients, vegetarian diets are usually rich in carbohydrates, n−6 fatty acids, dietary fibre, carotenoids, folic acid, vitamin C, vitamin E and Mg, and relatively low in protein, saturated fat, long-chain n−3 fatty acids, retinol, vitamin B12 and Zn; vegans may have particularly low intakes of vitamin B12 and low intakes of Ca. Cross-sectional studies of vegetarians and vegans have shown that on average they have a relatively low BMI and a low plasma cholesterol concentration; recent studies have also shown higher plasma homocysteine concentrations than in non-vegetarians. Cohort studies of vegetarians have shown a moderate reduction in mortality from IHD but little difference in other major causes of death or all-cause mortality in comparison with health-conscious non-vegetarians from the same population. Studies of cancer have not shown clear differences in cancer rates between vegetarians and non-vegetarians. More data are needed, particularly on the health of vegans and on the possible impacts on health of low intakes of long-chain n−3 fatty acids and vitamin B12. Overall, the data suggest that the health of Western vegetarians is good and similar to that of comparable non-vegetarians.


2018 ◽  
Vol 61 (4) ◽  
pp. 395-403
Author(s):  
Milan Margetín ◽  
Marta Oravcová ◽  
Jana Margetínová ◽  
Róbert Kubinec

Abstract. The fatty acid (FA) composition in the intramuscular fat (IMF) of the musculus longissimus dorsi (MLD) of Ile de France purebred lambs in two different production systems in Slovakia was evaluated using gas chromatography. In the first production system, lambs and ewes were assigned to pasture without access to concentrates (P). In the second system, lambs and ewes were confined indoors with hay/silage and access to concentrates (S). An analysis of variance with the following factors was employed: production system, sex, and production system–sex interactions. The proportions of arachidonic, eicosapentaeonic, docosapentaeonic, and docosahexaenoic FAs, i.e. long-chain polyunsaturated FA (PUFA), were significantly higher in P lambs (1.83, 0.82, 0.92, 0.29 g 100 g−1 FAME, respectively) than in S lambs (0.45, 0.14, 0.30, 0.09 g 100 g−1 FAME, respectively). The proportions of conjugated linoleic acid (CLA), n-6 PUFA, n-3 PUFA, and essential FA (linoleic and α-linolenic) were also significantly higher in P lambs (2.10, 8.50, 4.55, and 8.80 g 100 g−1 FAME, respectively) than in S lambs (0.65, 3.27, 1.50, and 3.64 g 100 g−1 FAME, respectively). The proportions of palmitic acid and myristic acid as important individual saturated FAs (SFA) were significantly higher in S lambs (28.51 and 8.30 g 100 g−1 FAME, respectively) than in P lambs (21.80 and 5.63 g 100 g−1 FAME, respectively). The proportion of all SFAs was also significantly higher in S lambs (57.87 g 100 g−1 FAME) than in P lambs (48.70 g 100 g−1 FAME). From a nutrition and human health point of view (i.e. higher proportions of PUFA, CLA, and essential FAs and lower proportions of SFAs), meat from P lambs was found to be more favourable and would be more highly recommended for consumption.


2020 ◽  
pp. 1-26
Author(s):  
Yan Wang ◽  
Yiwei Tang ◽  
Ye Ji ◽  
Wenhui Xu ◽  
Naeem Ullah ◽  
...  

Abstract In this study, we analysed the effects of single nucleotide polymorphism (SNP) rs174547 (T/C) in the fatty acid desaturase 1 (FADS1) gene on long-chain polyunsaturated fatty acid levels. Four databases were searched to retrieve related literature with keywords such as fatty acid, SNP, FADS1, and rs174547. A meta-analysis of the data was performed using Stata12.0 software, including summary statistics, test for heterogeneity, evaluation of publication bias, subgroup analysis, and sensitivity analysis. The associations between rs174547 in FADS1 and seven types of fatty acids, and delta-5 (D5D) and delta-6 fatty acid desaturase (D6D) activity were assessed based on the pooled results from 11 manuscripts. A total of 3713 individuals (1529 TT and 2184 TC+CC) were included. The results demonstrated that minor C allele carriers of rs174547 had higher linoleic acid (LA; P < 0.001) and α-linolenic acid (P = 0.020) levels, lower gamma linoleic acid (GLA; P = 0.001) and arachidonic acid (P = 0.024) levels, and lower D5D (P = 0.005) and D6D (P = 0.004) activities than the TT genotype group. Stratification analysis showed that minor C allele carriers of rs174547 had higher LA and lower GLA levels and lower D6D activities in plasma (LA, P < 0.001; GLA, P < 0.001; D6D activity, P < 0.001) samples and in Asian populations (LA, P < 0.001; GLA, P = 0.001; D6D activity, P = 0.001) than the TT genotype group. In conclusion, minor C allele carriers of the SNP rs174547 were associated with decreased activity of D5D and D6D.


1980 ◽  
Vol 239 (3) ◽  
pp. G141-G150 ◽  
Author(s):  
G. B. McDonald ◽  
D. R. Saunders ◽  
M. Weidman ◽  
L. Fisher

We studied the route of transport of long-chain fatty acids (LCFA) from the rat intestine. Lauric (12:0), myristic (14:0), palmitic (16:0), stearic (18:0), linoleic (18:2), and linolenic (18:3) acids were infused intraduodenally for 4 h as micellar solutions into unanesthetized thoracic duct-fistula rats. Proportionally more of each LCFA was transported by the portal vein at infusion rates of 0.3 mumol/h than at 15 mumol/h. Of the LCFA absorbed at low rates of infusion, 72% of lauric, 58% of myristic, 41% of palmitic, 28% of stearic, 58% of linoleic, and 68% of linolenic acid bypassed the lymphatic pathway. To test the inference that 58% of absorbed linoleate was transported by the portal vein, [14C]linoleic acid was infused at 0.3 or 15 mumol/h into unanesthetized rats equipped with both thoracic duct and portal venous fistulas. Portal venous blood (0.1 ml) was withdrawn every 30 min for 4 h. Proportionally more [14C]linoleate was recovered in portal blood at the low infusion rate. To examine the morphology of fat absorption, segments of rat jejunum in anesthetized rats were infused with micellar linoleic acid at 3 or 150 mumol/h. At 3-mumol/h infusion rate, an appearance identical to the fasting state was seen by electron microscopy. At 150 mumol/h, many larger chylomicron-sized particles appeared in absorptive cells, intercellular spaces, and lymphatics. We conclude that a substantial proportion of unsaturated LCFA is transported from rat intestine in portal venous blood.


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