CR quickies

I noticed this morning that I’ve let my “calorie restriction” bookmark folder swell to the fully-fed state, so without further ado or any added commentary on my part, here are the four most interesting abstracts from the past two weeks. Emphases and ellipses are mine.

CR and glycation: Dietary restriction, glycolysis, hormesis and ageing, AR Hipkiss:

The possibility is discussed that dietary restriction modulates ageing and onset of related pathologies by, in addition to upregulation of proteolysis, suppression of glycolysis which in turn decreases generation of methylglyoxal (MG), a highly toxic glycating agent which can provoke cellular senescence and many age-related pathologies. This proposal is supported by the observation that intermittent feeding can mimic dietary restriction’s effects on mouse lifespan without any overall reduction in calorie intake. … It is proposed that periods of fasting might be a more acceptable approach than permanent undernutrition in our attempts to slow human ageing, although timing of meals may prove important.

…and Alzheimer’s: Neuronal SIRT1 Activation as a Novel Mechanism Underlying the Prevention of Alzheimer Disease Amyloid Neuropathology by Calorie Restriction, Qin et al.:

… In this study we report for the first time that promotion of the NAD+-dependent sirtuin, SIRT1-mediated deacetylase activity, may be a mechanism by which CR influences Alzheimer disease (AD)-type amyloid neuropathology. Most importantly, we report that the predicted attenuation of beta-amyloid content in the brain during CR can be reproduced in mouse neurons in vitro by manipulating cellular SIRT1 expression/activity through mechanisms involving the regulation of the serine/threonine Rho kinase ROCK1, known in part for its role in the inhibition of the non-amyloidogenic {alpha}-secretase processing of the amyloid precursor protein. …

… and glucose tolerance: Calorie restriction initiated at middle age improved glucose tolerance without affecting age-related impairments of insulin signaling in rat skeletal muscle, Park et al.:

… CR initiated either at young or middle age improved glucose tolerance with a lower serum insulin response to glucose. However, middle-aged CR did not improve aging-related impairments in insulin signaling in QFM. The present results emphasized the possibilities of CR activation of an insulin-independent mechanism in skeletal muscle and also of the involvement of non-muscle tissues in glucose uptake.

…and the heart: Moderate calorie restriction improves cardiac remodeling and diastolic dysfunction in the Dahl-SS rat, Seymour et al. (feed me, Seymour!):

… While high-salt rats displayed features of decompensated pressure-overload hypertrophy, moderate calorie restriction remarkably reduced morbidity. Compared to the high-salt fed group, the high-salt, calorie-restricted group showed reduced blood pressure, delayed onset of cachexia, lower fasting hyperlipidemia, lower cardiac, renal and lung weight, less plasma IL-6 and TNF-α, less cardiac oxidative damage, and improved diastolic chamber function and cardiac index. Modest calorie restriction, independent of salt intake, reduced pathogenesis in this well described model of decompensated pressure-overload hypertrophy.

Summary: CR still good for you, especially if you happen to be a mouse, rat or monkey living under standard conditions in a small enclosure.