Protein is a building block of the body. It’s an amino acid that is an important part of a healthy diet. Protein helps to repair cells and make new ones, especially muscle. Good sources of protein include meats, milk, fish, and eggs.
A recent study conducted by researchers from New Zealand, Austria, and Demark have found that, despite protein being part of international guidelines, the recommended amount is insufficient to maintain muscle and strength, especially in older men.
The importance of muscle
The muscles we use on a daily basis, our skeletal muscles, are composed of protein filaments that slide past one another during contraction. If we don’t use our muscles for extended periods of time, like in disabling circumstances or underutilization, our muscles begin atrophy or decrease in mass. The protein in our diet helps mitigate this to some degree.
As we get older, we start doing less, which makes us use our voluntary muscles less. It is believed that by the time we reach our 50s, this natural decline begins to occur, leading to fragility, loss of independence, and a greater risk of dying.
The study in question looked at 30-year-old men who were supplied a balanced diet containing the recommended daily allowance (RDA) or double this amount. Protein levels were provided according to guidelines set by many international health agencies including the World Health Organization (WHO) and the United States Department of Agriculture (USDA) at 0.8 grams per kilogram of body weight.
Before and after the 10-week study, men had their muscle size, strength, physical function, and general health measured.
Improvement seen when protein was doubled
The results of the study showed that men who consumed the RDA of protein experienced a loss of muscle size and strength. The men who consumed double the RDA saw not see muscle and size increases, but saw an increase in power output, meaning they were able to better use bursts of force.
This indicates that men who eat more protein are able to perform basic abilities, such as walking up-stairs, much more efficiently.
“Our findings show the current WHO protein requirements are insufficient to maintain strength or muscle size in adults over age 70,” says study lead scientist Dr. Cameron Mitchell, a research fellow at the University of Auckland-based Liggins Institute.
He goes on to recommend that all older men should consume more high-quality meat at every meal to support muscle health. This includes animal sources such as dairy and meat, which are more efficient at promoting muscle growth than plant-based proteins.
However, the researchers admit that their study provides limited evidence and may be difficult to put in a real-world context. This study and previous ones done before it were carried out using protein supplementation rather than real food. Dietary supplement studies make it difficult to make global recommendations in terms of what regular people should be eating every day.