A new Canadian study suggest that spreading protein equally among the three daily meals could be linked to greater mass and muscle strength in the elderly than consumer the same levels of protein in just one or two sittings.
Study leader Dr Stéphanie Chevalier from the School of Human Nutrition at McGill University noted that many seniors consume the majority of their daily protein at lunch and dinner.
"We wanted to see if people who added protein sources to breakfast, and therefore had balanced protein intake through the three meals, had greater muscle strength," she said.
Writing in the American Journal of Clinical Nutrition, the team report that an even distribution of daily protein intake across meals is independently associated with greater muscle strength.
"We observed that participants of both sexes who consumed protein in a balanced way during the day had more muscle strength than those who consumed more during the evening meal and less at breakfast,” explained study first author Dr Samaneh Farsijani.
“However, the distribution of protein throughout the day was not associated with their mobility."
Protein and ageing
Loss of muscle is an inevitable consequence of aging that can lead to frailty, falls or mobility problems, said the team – who noted that eating enough protein is one way that has been shown to help prevent issues related to muscle loss and frailty in older age.
All body tissues, including the muscles, are composed of proteins – which themselves are made up of amino acids.
When protein intake decreases, the production of proteins in our muscles is not done correctly and this leads to a loss of muscle mass, said the team.
"Our research is based on scientific evidence demonstrating that older people need to consume more protein per meal because they need a greater boost of amino acids for protein synthesis," said Chevalier – adding that one of the essential amino acids known for protein renewal is leucine.
"It would be interesting to look into protein sources and their amino acid composition in future studies to further our observations."
Farsijani and colleagues examined both the amount of protein consumed and its distribution among people aged between aged 67 to 84 years, using the database from the Quebec longitudinal study on nutrition and aging called NuAge (Nutrition as a Determinant of Successful Aging).
They analysed data from the NuAge cohort, which included nearly 1,800 people who were followed for three years, reviewing protein consumption patterns of 827 healthy men and 914 healthy women to trying to establish links with variables such as strength, muscle mass or mobility.
"The NuAge study is one of the few studies gathering such detailed data on food consumption among a large cohort of elderly people,” commented study co-author Professor Hélène Payette of the Centre for Research on Aging at the Université de Sherbrooke.
Analysis revealed that a more-evenly distributed protein intake, independent of the total quantity, was associated with a higher muscle-strength score in both sexes throughout follow-up.
It was also associated with a greater mobility score, but only in men and only before adjustment for covariates, said the authors.
“A longer-term investigation of the role of protein intake and its distribution on physical performance is warranted, as are intervention studies, to support future recommendations,” concluded the Canadian team.
Source: American Journal of Clinical Nutrition
Volume 106, Number 1, Pages 113-124, doi: 10.3945/ajcn.116.146555
“Even mealtime distribution of protein intake is associated with greater muscle strength, but not with 3-y physical function decline, in free-living older adults: the Quebec longitudinal study on Nutrition as a Determinant of Successful Aging (NuAge study)”
Authors: Samaneh Farsijani, et al