Does long-term coffee intake reduce type 2 diabetes mellitus risk?

This review reports the evidence for a relation between long-term coffee intake and risk of type 2 diabetes mellitus. Numerous epidemiological studies have evaluated this association and, at this moment, at least fourteen out of eighteen cohort studies revealed a substantially lower risk of type 2 diabetes mellitus with frequent coffee intake. Moderate coffee intake (≥4 cups of coffee/d of 150 mL or ≥400 mg of caffeine/d) has generally been associated with a decrease in the risk of type 2 diabetes mellitus. Besides, results of most studies suggest a dose-response relation, with greater reductions in type 2 diabetes mellitus risk with higher levels of coffee consumption. Several mechanisms underlying this protective effect, as well as the coffee components responsible for this association are suggested. Despite positive findings, it is still premature to recommend an increase in coffee consumption as a public health strategy to prevent type 2 diabetes mellitus. More population-based surveys are necessary to clarify the long-term effects of decaffeinated and caffeinated coffee intake on the risk of type 2 diabetes mellitus

Fish oil supplementation alleviates metabolic and anxiodepressive effects of diet-induced obesity and associated changes in brain lipid composition in mice

Objective: Obesity significantly elevates the odds of developing mood disorders. Chronic consumption of a saturated high-fat diet (HFD) elicits anxiodepressive behavior in a manner linked to metabolic dysfunction and neuroinflammation in mice. Dietary omega-3 polyunsaturated fatty acids (n-3 PUFA) can improve both metabolic and mood impairments by relieving inflammation. Despite these findings, the effects of n-3 PUFA supplementation on energy homeostasis, anxiodepressive behavior, brain lipid composition, and gliosis in the diet-induced obese state are unclear. Methods: Male C57Bl/6J mice were fed a saturated high-fat diet (HFD) or chow for 20 weeks. During the last 5 weeks mice received daily gavage (“supplementation”) of fish oil (FO) enriched with equal amounts of docosahexaenoic (DHA) and eicosapentaenoic acid (EPA) or control corn oil. Food intake and body weight were measured throughout while additional metabolic parameters and anxiety- and despair-like behavior (elevated-plus maze, light–dark box, and forced swim tasks) were evaluated during the final week of supplementation. Forebrain lipid composition and markers of microglia activation and astrogliosis were assessed by gas chromatography–mass spectrometry and real-time PCR, respectively. Results: Five weeks of FO supplementation corrected glucose intolerance and attenuated hyperphagia in HFD-induced obese mice without affecting adipose mass. FO supplementation also defended against the anxiogenic and depressive-like effects of HFD. Brain lipids, particularly anti-inflammatory PUFA, were diminished by HFD, whereas FO restored levels beyond control values. Gene expression markers of brain reactive gliosis were supressed by FO. Conclusions: Supplementing a saturated HFD with FO rich in EPA and DHA corrects glucose intolerance, inhibits food intake, suppresses anxiodepressive behaviors, enhances anti-inflammatory brain lipids, and dampens indices of brain gliosis in obese mice. Together, these findings support increasing dietary n-3 PUFA for the treatment of metabolic and mood disturbances associated with excess fat intake and obesity