Animal protein linked to better health in older men
According to a recent Japanese study of nutrition in older adults, older men may gain a boost physically, mentally and socially from a diet rich in meat and fish. The study, conducted by the National Institute of Health and Nutrition in Tokyo, evaluated about a thousand men and women for a period of seven years. The average age of the study participants was 67.
The study suggested that men who indicated a greater amount of meat and fish in their diet reduced their odds of mental and physical decline by 39 percent, compared with men who ate less animal protein. They tended to be more socially active as well.
But the same association was not seen in women. Nor were the same benefits linked to proteins from plants, the researchers found.
The study doesn't actually prove that eating meat and fish caused the men's health improvements, or that low animal protein intake contributes to early decline, however.
"It is an observational study that simply shows a relationship between protein and functional decline. It does not prove cause and effect," said Lona Sandon, an assistant professor of clinical nutrition at the University of Texas Southwestern Medical Center at Dallas.
Although the study was conducted in Japanese men and women, and may not be directly relatable to people living in the U.S., the research does indicate that adequate protein intake is important as people age. The ability to process protein may decline in old age. As a result, protein requirements may increase.
"High-quality protein can help preserve lean muscle that is lost with aging and can affect daily functioning," Sandon said. And higher-quality proteins found in animal sources are more easily used by the body than plant sources."
Don't take that as license to run off to the nearest burger joint, however. There are important factors to take into consideration when it comes to protein consumption.
The leading cause of death in American men is heart disease. The type and quality of the animal meats people consume can be a contributing factor. A diet laden with red and processed meat is associated with cardiovascular disease, diabetes, certain cancers and dementia.
Connie Diekman, director of nutrition at Washington University in St. Louis, noted that the intensity of exercise - an important factor in building muscle - was not accounted for in the study population. Regular exercise is needed to help the body turn meat protein into muscle mass.
"This study says to me that we need to keep adequate amounts of protein and a good diversity of protein sources, especially fish, throughout our life," Diekman said.
In general, as people age, they lose muscle mass. They also tend to consume less protein and fewer calories than needed to compensate for this loss. Losing muscle mass affects quality of life, organ health and the immune system.
However, overloading the body with protein is not the answer. As we age, our kidneys and other organs may not be able to handle excessive amounts of protein. Popular high-protein diets may cause more harm than
There must be a balance. A healthy diet should include healthy sources of protein, including fish, chicken, legumes and nuts. But fruits and vegetables - as well as healthy fluids - still play a very important role.