06 January 2025
Unlocking the secrets of protein digestion in older adults
A collaboration between Teagasc and Munster Technological University (MTU) has offered new insights into protein’s role in healthy aging. Teagasc Walsh Scholar, Aoife Burke shares key insights from the Department of Agriculture, Food and the Marine funded INFOTECH Project.
In Ireland, one in four adults are over the age of 60. Aging is an inevitable process and with it comes a gradual decline in muscle mass and strength. This loss of muscle leads to frailty. A significant risk factor for frailty is protein-energy malnutrition (PEM), which results from either inadequate protein intake in our diet or physiological changes in the body that hinder digestion, absorption, or utilisation of protein.
To delay frailty, high-quality protein intake is a key recommendation. Current recommendations suggest increasing dietary protein to 1.0–2.0 g/kg of body weight per day to meet the needs of older adults. However, not all proteins from our diet are created equal. They differ in amino acid composition, the building blocks of proteins, and the ease in which protein is digested in the human gut.
Key insights
Within the Department of Agriculture, Food and the Marine funded INFOTECH project, Teagasc and our MTU collaborators set out to look at protein intake in older adults in Ireland. Crunching the numbers gave us insights into individual amino acid intake. We then created models in the laboratory to examine digestion in the older adult gut. Finally, we were able to track absorption of amino acids by using aged human intestinal cells.
The study used a dataset of 2,326 food items from the National Adult Nutritional Survey (IUNA, 2011). The results of this analysis showed that the older Irish population are meeting the recommended daily intake of essential amino acids.
Our digestion model showed that the slower passage of food through the aged gut increased protein digestion and the release of amino acids. Not surprisingly, protein digestion is also influenced by the food type (meat versus bread versus beverage). Early results from our aged intestinal cells showed no decrease in amino acid absorption. Taken together, these results tell us that the older adult in Ireland is currently consuming sufficient protein in their diet, they can digest this protein and absorb the amino acids, albeit it takes a little longer.
The development of these laboratory models in Teagasc provide researchers with a non-invasive way to observe how aging impacts digestion. This approach allows for detailed analysis of the digestion process without the need for human volunteers, providing essential data that would be difficult to obtain through traditional methods.
Aoife Burke is a Teagasc Walsh Scholar and PhD candidate in the Teagasc Food Research Centre, Moorepark.
Also read: New EU project to bring healthier, minimally processed plant-based foods to Europe