Do older adults need more protein?
by Newsletter Editor
When you ingest protein, the amino acids that are digested and absorbed into the bloodstream trigger a response in muscle to convert amino acids into protein. This anabolic response to the ingestion of protein is one of the main reasons whey and other protein supplements are popular as post-exercise supplements. However, research has shown that as you age you tend to become resistant to this positive effect of protein ingestion. The good news is that research indicates that this ‘anabolic resistance’ can be overcome by ingesting greater amounts of protein, especially leucine.
For example, in one recent study, elderly individuals had a 69% greater increase in muscle protein synthesis after exercise when they consumed 20 grams of whey (2.6 grams of leucine) compared to 20 grams of casein (1.6 grams of leucine). In an older group of active 70-year-olds, it was shown that 40 grams of whey consumed after resistance exercise produced a 32% greater increase in muscle protein synthesis compared to a 20 gram dose of whey. In contrast, 20 grams of protein appears to be enough to maximize muscle protein synthesis in younger individuals.
Recent results from training studies have demonstrated that greater amounts of protein are needed to overcome the blunted response to protein older adults experience. In one of these experiments, 80 adults 70 to 85 years of age participated in a resistance training program (3 days per week) for 6 months. One group was randomized to receive whey protein (20 grams two times per day) while another group received carbohydrate as a control. The whey group had greater increases in lean body mass (1.3 vs 0.7 pounds) than the carbohydrate group. This was confirmed by greater muscle mass in the thigh from computed tomography (4.6 vs 2.9%).
In summary, older adults need a higher protein dose than younger people. Older adults should consume at least 20-40 grams of whey after exercise to achieve a maximal increase in muscle protein synthesis.
Reference: Burd NA, Yang Y, Moore DR, Tang JE, Tarnopolsky MA, Phillips SM. Greater stimulation of myofibrillar protein synthesis with ingestion of whey protein isolate v. micellar casein at rest and after resistance exercise in elderly men. Br J Nutr. 2012 Jan 31:1-5.
Yang Y, Breen L, Burd NA, Hector AJ, Churchward-Venne TA, Josse AR, Tarnopolsky MA, Phillips SM. Resistance exercise enhances myofibrillar protein synthesis with graded intakes of whey protein in older men. Br J Nutr. 2012 Feb 7:1-9.
Chalé A, Cloutier GJ, Hau C, Phillips EM, Dallal GE, Fielding RA. Efficacy of whey protein supplementation on resistance exercise-induced changes in lean mass, muscle strength, and physical function in mobility-limited older adults. J Gerontol A Biol Sci Med Sci. 2013 Jun;68(6):682-90.