Saturated fatty acid

About: Saturated fatty acid is a research topic. Over the lifetime, 9457 publications have been published within this topic receiving 253247 citations.

Fatty acid-induced NLRP3-ASC inflammasome activation interferes with insulin signaling

Abstract: High-fat diet (HFD) and inflammation are key contributors to insulin resistance and type 2 diabetes (T2D). Interleukin (IL)-1b plays a role in insulin resistance, yet how IL-1b is induced by the fatty acids in an HFD, and how this alters insulin signaling, is unclear. We show that the saturated fatty acid palmitate, but not unsaturated oleate, induces the activation of the NLRP3-ASC inflammasome, causing caspase-1, IL-1b and IL-18 production. This pathway involves mitochondrial reactive oxygen species and the AMP-activated protein kinase and unc-51–like kinase-1 (ULK1) autophagy signaling cascade. Inflammasome activation in hematopoietic cells impairs insulin signaling in several target tissues to reduce glucose tolerance and insulin sensitivity. Furthermore, IL-1b affects insulin sensitivity through tumor necrosis factor–independent and dependent pathways. These findings provide insights into the association of inflammation, diet and T2D.

Effect of dietary trans fatty acids on high-density and low-density lipoprotein cholesterol levels in healthy subjects.

Abstract: Background. Fatty acids that contain a trans double bond are consumed in large amounts as hydrogenated oils, but their effects on serum lipoprotein levels are unknown. Methods. We placed 34 women (mean age, 26 years) and 25 men (mean age, 25 years) on three mixed natural diets of identical nutrient composition, except that 10 percent of the daily energy intake was provided as oleic acid (which contains one cis double bond), trans isomers of oleic acid, or saturated fatty acids. The three diets were consumed for three weeks each, in random order. Results. On the oleic acid diet, the mean (±SD) serum values for the entire group for total, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol were 4.46+0.66, 2.67±0.54, and 1.42±0.32 mmol per liter (172±26, 103±21, and 55±12 mg per deciliter), respectively. On the trans-fatty-acid diet, the subjects' mean HDL cholesterol level was 0.17 mmol per liter (7 mg per deciliter) lower than the mean value on the diet high in oleic acid...

Shifts in the structure of soil microbial communities in limed forests as revealed by phospholipid fatty acid analysis

Abstract: The effects of lime and wood-ash on the microbial community structure were evaluated by analyzing the phospholipid fatty acid (PLFA) composition of soils from two areas in the south of Sweden. A pine forest was amended with lime or ash at two concentrations, and a spruce forest was limed at one concentration. The treatments were carried out 5–6 years before sampling and raised the pH from approx. 4.0 to values between 4.8 and 7.0. At both sites there was a difference in the PLFA composition between the treated plots and the controls. The changes found were similar at both sites and correlated to the pH changes. No difference was found between limed plots and those treated with wood-ash. The methyl-branched fatty acids i15:0, i16:0 and 10Me16:0, the monounsaturated fatty acids 16: 1ω 7t and 18: 1ω 9, the cyclopropane fatty acid cy 19:0, and the saturated fatty acid 20:0 were more abundant in the control plots. In the plots with the highest pH there was a three-fold increase in the fatty acid 16: lω 5. An increase was also found for the fatty acids i14:0, 16:lω9, 16:lω 7c, cy17:0, 18:lω 7 and 10Me18:0. No effect on 18:2ω6 was found. The changes in PLFA pattern indicated that the increased pH caused a shift in the bacterial community to more Gram-negative and fewer Gram-positive bacteria, while the amount of fungi was unaffected. The increase in 10Me18:0 in limed soils indicated an increase in actinomycetes.

Substituting dietary saturated for monounsaturated fat impairs insulin sensitivity in healthy men and women: The KANWU Study.

Abstract: Aims/hypothesis. The amount and quality of fat in the diet could be of importance for development of insulin resistance and related metabolic disorders. Our aim was to determine whether a change in dietary fat quality alone could alter insulin action in humans. Methods. The KANWU study included 162 healthy subjects chosen at random to receive a controlled, isoenergetic diet for 3 months containing either a high proportion of saturated (SAFA diet) or monounsaturated (MUFA diet) fatty acids. Within each group there was a second assignment at random to supplements with fish oil (3.6 g n-3 fatty acids/d) or placebo. Results. Insulin sensitivity was significantly impaired on the saturated fatty acid diet (-10 %, p = 0.03) but did not change on the monounsaturated fatty acid diet ( + 2 %, NS) (p = 0.05 for difference between diets). Insulin secretion was not affected. The addition of n-3 fatty acids influenced neither insulin sensitivity nor insulin secretion. The favourable effects of substituting a monounsaturated fatty acid diet for a saturated fatty acid diet on insulin sensitivity were only seen at a total fat intake below median (37E %). Here, insulin sensitivity was 12.5 % lower and 8.8 % higher on the saturated fatty acid diet and monounsaturated fatty acid diet respectively (p = 0.03). Low density lipoprotein cholesterol (LDL) increased on the saturated fatty acid diet ( + 4.1 %, p 37E %). [Diabetologia (2001) 44: 312–319]