CR May Provide Some Protection Against Age Related Muscle Loss (Sarcopenia), Based On Animal Studies
Following are excerpts and references from animal studies of the effects of CR on sarcopenia - the loss of muscle due to aging. In all cases the original paper should be read for a full understanding of what was being studied and what could be concluded.
Wisconsin National Primate Research Center, University of Wisconsin, Madison, WI 53715, United States. shmckier@wisc.edu
"Sarcopenia is the age-related loss of skeletal muscle mass and function and is characterized by a reduction in muscle mass and fiber cross-sectional area, alterations in muscle fiber type and mitochondrial functional changes. In rhesus monkeys, calorie restriction (CR) without malnutrition improves survival and delays the onset of age-associated diseases and disorders including sarcopenia. We present a longitudinal study on the impact of CR on early stage sarcopenia in the upper leg of monkeys from ~16 years to ~22 years of age...we show that CR delayed the development of maximum muscle mass and, unlike Control animals, muscle mass of the upper leg was preserved in CR animals during early phase sarcopenia... "
Title: "Attenuation of sarcopenia by dietary restriction in rhesus monkeys."
J Gerontol A Biol Sci Med Sci. 2008 Jun;63(6):556-9.; Colman RJ, Beasley TM, Allison DB, Weindruch R.
Wisconsin National Primate Research Center, University of Wisconsin-Madison, 1220 Capitol Ct., Madison, WI 53715, USA. rcolman@primate.wisc.edu
"Sarcopenia, the loss of muscle mass with normal aging, devastates quality of life-and related healthcare expenditures are enormous. ...Furthermore, DR opposes sarcopenia in rodents. We tested the hypothesis that DR will reduce age-related sarcopenia in a nonhuman primate. Thirty adult male rhesus monkeys, half fed a normal calorie intake and half reduced by 30% in caloric intake, were examined over 17 years for changes in dual-energy X-ray absorptiometry-estimated skeletal muscle mass. Body weight-adjusted skeletal muscle mass declined somewhat in both groups but was far more rapid in the control group. We have shown that moderate, adult-onset DR can attenuate sarcopenia in a nonhuman primate model."
Title: "Early-onset calorie restriction conserves fiber number in aging rat skeletal muscle."
FASEB J. 2004 Mar;18(3):580-1. Epub 2004 Jan 20.; McKiernan SH, Bua E, McGorray J, Aiken J.
Department of Animal Health and Biomedical Sciences, University of Wisconsin, Madison, Wisconsin 53706, USA.
"The purpose of this work was to determine the effect of early-onset calorie restriction on sarcopenia in the aging rat. Ad libitum (AL) fed animals were examined at 5, 18, 21, and 36 months of age. Calorie-restricted (CR) rats, 40% restricted since 4 months of age, were examined at 21 and 36 months of age. ...Calorie restriction did not prevent muscle mass loss with age; however, it significantly reduced muscle mass loss between 21 and 36 months of age compared with age-matched AL cohorts. Calorie restriction prevented fiber loss with age, and this conservation of fiber number reduced muscle mass loss with age."