Low-certainty evidence was found that a reduction in unprocessed red meat intake of 3 servings per week is associated with a very small reduction in risk for cardiovascular mortality, stroke, myocardial infarction (MI), and type 2 diabetes. Likewise, low-certainty evidence was found that a reduction in processed meat intake of 3 servings per week is associated with a very small decrease in risk for all-cause mortality, cardiovascular mortality, stroke, MI, and type 2 diabetes. LIMITATION: Inadequate adjustment for known confounders, residual confounding due to observational design, and recall bias associated with dietary measurement. CONCLUSION: The magnitude of association between red and processed meat consumption and all-cause mortality and adverse cardiometabolic outcomes is very small, and the evidence is of low certainty.
Youm YH, Nguyen KY et al
We report that BHB, but neither acetoacetate nor structurally-related short chain fatty acids, butyrate and acetate, suppresses activation of the NLRP3 inflammasome in response to several structurally unrelated NLRP3 activators, without impacting NLRC4, AIM2 or non-canonical caspase-11 inflammasome activation. Mechanistically, BHB inhibitsNLRP3 inflammasome by preventing K+ efflux and reducing ASC oligomerization and speck formation. The inhibitory effects of BHB on NLRP3 were not dependent on chirality or classical starvation regulated mechanisms like AMPK, reactive oxygen species (ROS), autophagy or glycolytic inhibition. BHB blockedNLRP3 inflammasome without undergoing oxidation in TCA cycle, independently of uncoupling protein-2 (UCP2), Sirt2, receptor Gpr109a and inhibition of NLRP3 did not correlate with magnitude of histone acetylation in macrophages. BHB reduced the NLRP3 inflammasome mediated IL-1β and IL-18 production in human monocytes. In vivo, BHB attenuates caspase-1 activation and IL-1β secretion in mouse models of NLRP3-mediateddiseases like Muckle-Wells Syndrome (MWS), Familial Cold Autoinflammatory syndrome (FCAS) and urate crystal induce body cavity inflammation. Taken together, these findings suggest that the anti-inflammatory effects of caloric restriction or ketogenic diet may be mechanistically linked to BHB-mediated inhibition of the NLRP3 inflammasome, and point to the potential use of interventions that elevate circulating BHB against NLRP3-mediated proinflammatory diseases.
Canonical Nlrp3 inflammasome links systemic low-grade inflammation to functional decline in aging.
Youm YH, Grant RW, McCabe LR et al
Consistent with the hypothesis that systemic low-grade inflammationpromotes age-related degenerative changes, the deficient Nlrp3 inflammasome-mediated caspase-1 activity improvedglycemic control and attenuated bone loss and thymic demise. Notably, IL-1 mediated only Nlrp3 inflammasome-dependent improvement in cognitive function and motor performance in aged mice. These studies reveal Nlrp3 inflammasome as an upstream target that controls age-related inflammation and offer an innovative therapeutic strategy to lowerNlrp3 activity to delay multiple age-related chronic diseases. Although, it remains unknown whether reduction in Nlrp3 activation can extend lifespan, our data demonstrate unequivocally that deletion of Nlrp3 inflammasome enhances healthspan and prevents functional decline in multiple organs, including protection against thymic demise, cataract development, glucose intolerance and also enhances cortical and trabecular bone mass.
These studies reveal Nlrp3 inflammasome as an upstream target that controls age-related inflammation and offer innovative therapeutic strategy to lowerNlrp3 activity to delay multiple age-related chronic diseases.