The medical community has presented findings on both the pros and cons of eating a diet high in animal protein as of late. But now, researchers publishing in the Journal of the American Geriatrics Society suggest consuming a diet high in animal protein could help older men function at higher physical, psychological and social levels.
In the great animal protein debate, another series of studies recently suggested that consuming too much protein in middle age is "as bad as smoking" and recommended consuming low protein levels for a long and healthy life.
Another study, published in the Proceedings of the National Academy of Sciences, suggested that eating grilled meat increases risk of Alzheimer's disease.
But investigators from this latest study say recent research indicates that aging could reduce the ability of the body to absorb or process proteins. They say this could mean our requirement for protein increases with age.
With increasing life expectancies in certain countries, the team notes that higher numbers of older people are living with functional decline, which includes deteriorating cognitive ability and capacity to carry out daily activities.
Aside from the emotional impact this can have on individuals, the researchers say increasing functional decline can also impact the economies of these countries.
As a result, the team, led by Megumi Tsubota-Utsugi of the National Institute of Health and Nutrition in Japan, looked at whether intake of protein could affect the functional ability of elderly men and women.
Link to reduced decline was with animal, not vegetable protein
Elderly men who consumed a diet high in animal protein had a 39% decreased risk of functional decline, the study shows.
They conducted their study, which focused on the relationship between protein intake and future decline in higher-level functional capacity, using residents of the general elderly community-dwelling population of Japan.
In total, they followed 1,007 individuals who were an average age of 67.4 years old. The participants completed food questionnaires at the beginning of the study and then again 7 years later.
Dividing the participants into quartiles according to intake levels of total, animal and plant protein, the researchers then performed tests of higher-level functional capacity, which included social and intellectual components, as well as tests related to daily living activities.
Their results showed that men from the group who consumed the most animal protein had a 39% decreased risk of encountering higher-level functional decline, compared with those who consumed the least amount of animal protein.
Though their findings are significant, the team notes that they did not observe this link in women. Also, they did not find a link between plant protein intake and functional decline in men or women.
Commenting on their findings, Tsubota-Utsungi says:
"Identifying nutritional factors that contribute to maintaining higher-level functional capacity is important for prevention of future deterioration of activities of daily living. Along with other modifiable health behaviors, keeping higher protein intake could contribute to maintaining elderly functional capacity."
The study abstract does not detail the breakdown of what kind of animal protein the men in the highest quartile consumed, but it specifies that plant protein did not lower risks of functional decline.