Deterioration of skeletal muscle mass is a common occurrence in people as they age (known as sarcopenia) and also accompanying certain diseases.
One of the causes is a reduced ability to regulate the synthesis of muscle protein and disruption in muscle protein breakdown rates. Protein ingestion is an important part of skeletal muscle mass maintenance over the lifespan and can become impaired as we get older, leading to slower and lower rates of ingestion and associated effects on muscle mass retention.
Researchers have proposed the overnight period as an opportune window to promote muscle protein synthesis. They looked at the effect of different amounts of protein ingested before sleep on overnight muscle protein synthesis.
The study involved 48 healthy, older men who were randomly assigned to one of four groups. The first three groups were assigned one of four different quantities of protein, administered intravenously overnight and the fourth group a placebo. Muscle biopsies were extracted from participants.
Protein was observed to be properly digested and absorbed throughout the night. This resulted in increased overnight plasma amino acid availability and protein synthesis during sleep in the healthy older men assigned to the protein groups. Compared to the placebo group, those taking 40g of protein before sleep had increased overnight muscle protein synthesis rates. Those receiving smaller doses of protein did not have substantially different outcomes to the placebo group.
The results of this study suggest that protein consumed before sleep may assist in reducing muscle mass deterioration in older men. This study had a small sample size so results should be interpreted with caution and warrant the need for additional research in this area of nutritional investigation. Ingesting protein before sleep may assist in preserving muscle mass in aging and diseased populations. Watch this space for more nutritional research to corroborate these findings.