High whey protein intake delayed the loss of lean body mass in healthy old rats, whereas protein type and polyphenol/antioxidant supplementation had no effects

PLoS One. 2014 Sep 30;9(9):e109098. doi: 10.1371/journal.pone.0109098. eCollection 2014.

Abstract

Our aim was to compare and combine 3 nutritional strategies to slow down the age-related loss of muscle mass in healthy old rats: 1) increase protein intake, which is likely to stimulate muscle protein anabolism; 2) use leucine rich, rapidly digested whey proteins as protein source (whey proteins are recognized as the most effective proteins to stimulate muscle protein anabolism). 3) Supplement animals with a mixture of chamomile extract, vitamin E, vitamin D (reducing inflammation and oxidative stress is also effective to improve muscle anabolism). Such comparisons and combinations were never tested before. Nutritional groups were: casein 12% protein, whey 12% protein, whey 18% protein and each of these groups were supplemented or not with polyphenols/antioxidants. During 6 months, we followed changes of weight, food intake, inflammation (plasma fibrinogen and alpha-2-macroglobulin) and body composition (DXA). After 6 months, we measured muscle mass, in vivo and ex-vivo fed and post-absorptive muscle protein synthesis, ex-vivo muscle proteolysis, and oxidative stress parameters (liver and muscle glutathione, SOD and total antioxidant activities, muscle carbonyls and TBARS). We showed that although micronutrient supplementation reduced inflammation and oxidative stress, the only factor that significantly reduced the loss of lean body mass was the increase in whey protein intake, with no detectable effect on muscle protein synthesis, and a tendency to reduce muscle proteolysis. We conclude that in healthy rats, increasing protein intake is an effective way to delay sarcopenia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / drug effects*
  • Aging / metabolism
  • Animals
  • Body Weight / drug effects
  • Chamomile / chemistry
  • Diet / methods
  • Dietary Supplements*
  • Eating / drug effects
  • Fibrinogen / metabolism
  • Glutathione / metabolism
  • Male
  • Muscle Proteins / agonists
  • Muscle Proteins / metabolism*
  • Muscle, Skeletal / drug effects*
  • Muscle, Skeletal / metabolism
  • Organ Size / drug effects
  • Plant Extracts / administration & dosage
  • Rats
  • Rats, Wistar
  • Sarcopenia / prevention & control*
  • Superoxide Dismutase / metabolism
  • Thiobarbituric Acid Reactive Substances / metabolism
  • Vitamin D / administration & dosage
  • Vitamin E / administration & dosage
  • Whey Proteins / administration & dosage*
  • alpha-Macroglobulins / metabolism

Substances

  • Muscle Proteins
  • Plant Extracts
  • Thiobarbituric Acid Reactive Substances
  • Whey Proteins
  • alpha-Macroglobulins
  • Vitamin D
  • Vitamin E
  • Fibrinogen
  • Superoxide Dismutase
  • Glutathione

Grants and funding

This study was supported by Danone Research, France. The protocol was discussed and designed in collaboration with the funder, and it was agreed that we would publish the results. We then performed data collection and analysis, and wrote the manuscript. The funder assisted in reviewing the manuscript.