Scientists at the University of Texas Medical Branch at Galveston have good news for people who want to stay strong in their old age: older bodies are just as good as young ones at turning protein-rich food into muscle.
A new study suggests that a diet containing a moderate amount of protein-rich food such as beef, fish, pork, chicken, dairy or nuts may help slow the deterioration of elderly people's muscles.
Reducing the decline in muscle mass among the elderly is crucial to maintaining their health and independence, these researchers say. And they add that consuming adequate protein is essential for making and maintaining muscles. Since nutritional studies show that many elderly individuals eat less protein than the average person, researchers have reasoned that if the elderly simply increased their protein intake, they might slow down muscle loss , as long as old age doesn't inherently interfere significantly with the ability to make muscles out of the protein in food.
"We wanted to know if there is some reason your grandmother's body, for example, can't stimulate muscle growth in response to eating the same protein-rich meal that you eat, which might over time contribute to muscle loss," said Douglas Paddon-Jones, an associate professor in UTMB's departments of physical therapy and internal medicine. Paddon-Jones is the senior author of a paper on the study published in the August issue of the American Journal of Clinical Nutrition and now available online.
The investigation compared changes in muscle protein synthesis in 10 young and 10 elderly volunteers after eating a four-ounce serving of lean beef. By analyzing blood and muscle samples, the researchers were able to measure the rate at which a particular individual's body built muscle protein. During the five hours after the young and elderly volunteers ate the beef, both groups muscle protein synthesis increased by 50 percent.
"We've done studies in the past with specialized drinks containing amino acids , the chemical building blocks of proteins , but this was the first time anybody's looked at a real food and its ability to stimulate muscle growth in both the young and elderly," Paddon-Jones said. "What we learned was really encouraging, because it suggests that elderly people actually can benefit from eating a moderate serving of protein-rich foods. That's something they aren't doing enough now , in fact, between 16 and 27 percent of older adults are eating less than the USDA's recommended daily allowance of protein."