Submitted to: Lipids
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/5/2015
Publication Date: 5/2/2016
Publication URL: http://handle.nal.usda.gov/10113/62519
Citation: Sundaram, S., Bukowski, M.R., Lie, W., Picklo, M.J., Yan, L. 2016. High-fat diets containing different amounts of n-3 polyunsaturated acids modulate adipokine production in mice. Lipids. 51(5):571-582.
Interpretive Summary: Fat tissue produces hormones that contribute to metabolic disturbance and obesity. However, not all of the fats are created equally. For example, fish oil has been suggested to alleviate adverse inflammatory effects of fat-produced hormones. In the present study, we compared different oils on body fat build-up and fat hormone production in mice fed a low-fat corn oil-based diet in comparison with mice fed a high-fat diet containing corn, fish, flaxseed, soybean or sunflower oil. Compared to the low-fat diet, the high-fat diets, regardless of the type of oil, significantly increased body fat mass and body weights, and there were no differences in these measurements among the high-fat diet-fed groups. However, the high-fat fish oil diet significantly reduced concentrations of leptin and increased concentrations of adiponectin in blood and fat tissue compared to other high-fat diets. Leptin is a fat-produced pro-inflammatory hormone that contributes to obesity, and adiponectin is a fat-produced anti-inflammatory hormone that reduces fat build-up. Furthermore, fish oil, compared to other types of oils, prevented high-fat diet-induced significant elevation of insulin in blood. We conclude that fish oil or fish oil components may be beneficial in improving insulin sensitivity and reducing high-fat diet-induced metabolic disturbance by up-relation of adiponectin and down-regulation of leptin.
Technical Abstract: Dysregulation of adipokines is a hallmark of obesity. Polyunsaturated (n3) fatty acids in fish oil may exert anti-inflammatory effects on adipose tissue mitigating the dysregulation of adipokines thereby preventing obesity. This study investigated the effects of high-fat diets containing different amounts and types of n3 polyunsaturated fatty acids (PUFA) on adiposity and adipokine production in mice. Mice were fed a low-fat or a high-fat diet with 16% or 45% of energy from corn oil (low n3 PUFA) in comparison with a high-fat diet containing soybean or high-oleic sunflower (adequate n3 PUFA), flaxseed or fish oil (high n3 PUFA) for 11 weeks. High-fat diets, regardless of types of oils, significantly increased body fat mass and body weights compared to the low-fat diet. Adipose fatty acid composition and contents reflected dietary fatty acid profiles. The high-fat fish oil diet significantly increased adiponectin and reduced leptin concentrations in both plasma and adipose tissue but did not elevate plasma insulin concentration compared to the high-fat corn oil diet. All high-fat diets elevated concentrations of plasminogen activator inhibitor-1 and monocyte chemoattractant protein-1 but lowered resistin concentrations in both plasma and adipose tissue. In conclusion, fish oil may be beneficial in improving insulin sensitivity by upregulation of adiponectin and downregulation of leptin production. However, n3 PUFA at dietary levels tested do not play a role or are insufficient in reducing adiposity and production of pro-inflammatory cytokines.