A new study, published in Frontiers in Exercise and Sports Nutrition, says that an increased intake of protein in the breakfast and lunch can help mitigate age-related muscle loss in older adults.
— Smeuninx Benoit (@benoitsmeuninx) March 16, 2020
The progressive age-related muscle wasting, called sarcopenia, occurs as a result of complex chemistry between muscle protein synthesis (MPS) and muscle protein breakdown (MPB). Sarcopenia takes a hike after 45 years of age and can damage independence and quality of life by increasing the risk of falls. Older adults are particularly prone to developing age-related anabolic resistance, an abnormal response of muscles to anabolic stimuli, which further leads to muscular atrophy. Anabolic stimuli, which include insulin, insulin-like growth-factors and branched-chain amino acids (BCAA), are muscle builders. However, there is enough evidence to suggest that dietary intake of protein stimulates MPS and restores muscle mass in middle-aged and older adults.
Protein Intake Should be Spread Across All Meals to Maximize Benefits
The study in question focused on the patterns and source of proteins consumed and found that just eating more proteins does not suffice; the older adults must ensure the intake is spread across all the meals.
Proteins are the building block of muscles. These are made up of tiny blocks of energy, called amino acids, that build and repair tissues.
Every adult, irrespective of age and gender, should take 0.8 g per kg of proteins per day to meet the metabolic demands of the body. The older adults need to increase the intake to 1-1.5 g/kg/day to retain and increase muscle strength. The commonly identified source of proteins includes meat, poultry, eggs, cheese, milk, fish, nuts, soya, yogurt and oats.
For the study at the University of Birmingham, researchers recruited 120 participants and divided them into three age groups; young (average age 23), middle-aged (age 51) and older adults (age 77 and over). Each participant was asked to maintain a food diary by logging in every eatable for three days. The purpose was to identify dietary behavior and eating pattern (particularly protein) among the subjects.
The results showed a wide variation in eating behavior. Almost all participants consumed the recommended daily allowance (RDA) of proteins, yet there existed 18 different patterns with older people not just consuming low-quality proteins (from bread), they were mostly restricting the intake to lunch only, which according to the lead author and post-doctoral researcher at UOB, Dr. Benoit Smeuninx, is a tad inappropriate.
Old individuals consumed on average 83.4 ± 24.6 g of daily protein, which was significantly lower compared with young but not middle-aged individuals who consumed, respectively, 105.1 ± 43.0 g and 97.0 ± 31.1 g of daily protein. Sources of protein consumption were similar between groups except at lunch were old individuals ingested lower quality proteins compared with middle-aged and young individuals.
Dr. Benoit recommends that older adults include proteins in breakfast and lunch every day to stimulate MPS and slow down sarcopenia. In the study, the older adults mostly preferred plant-based proteins over animal-based proteins which may be another reason for quick muscle wasting.
When Health Units approached him and asked whether he suggests revising current RDA for dietary proteins to prevent deficiencies in older adults, he commented:
Our study is the first to directly analyze dietary habits across different age groups and I believe it needs to be taken further to explore absolute and relative protein intake. However, our findings strongly support rolling out per-meal protein intake recommendations, particularly for older adults to ensure muscle anabolic effect.