Our bodies undergo significant changes as we grow older. Those changes include sarcopenia, cognitive decline, hormonal decline and changes in nutritional needs. As the gastrointestinal (GI) tract changes with aging, nutrition challenges arise. Rémond et al. have an extensive review of the physiological changes of the GI tract.1
The mouth, for starters, decreases saliva production. From there we move to the stomach, where the incidence of stomach infections increases, which affects stomach acid production. The normal turnover of mucosal cells does not appear to change in the intestine, and the integrity of the intestinal barrier also stays steady. However, production of digestive enzymes decreases and changes in the endocrine system impact how we feel about food and satiety. These physiological changes also have the potential to be modulated by use of medicinal drugs.
These changes bring associated consequences to the absorption of ingested nutrients. Aging populations are at risk for many nutrient deficiencies. According to one review, those shortfall nutrients include omega-3 fatty acids, protein, zinc, magnesium, fiber and several vitamins.2 The review further stated lack of these nutrients can be associated with health problems among the aging population.
One of the biggest visible changes that comes with aging is loss of lean muscle mass, or sarcopenia. The previously mentioned changes to the GI tract can be a factor in this loss. Additionally, with age, anabolic response is desensitized and the mTORC1 (mammalian target of rapamycin complex 1) signaling of protein synthesis is blunted. Several studies have evaluated not only the amount of protein that is needed in the elderly population, but the quality of the protein as well. These studies are summarized in a review article by Baum et al.3 They summarized protein consumption for elderly adults should be between 1.2 and 2.0 g/kg/d, which is a significant increase over the current recommended dietary allowance (RDA) of 0.8 g/kg/day for all adults ages 18 and over. Additionally, the amino acid composition and quality of the protein need to be taken into consideration to ensure that essential amino acid intake is adequate, particularly leucine. The energy content of the protein can be a factor in the quality of the protein. Sarcopenia can be a large contributor to loss of independence.4 Adequate consumption of a high-quality protein source can help in stimulating the anabolic pathways for muscle synthesis and preserving muscle mass.5
Learn more about critical ingredients for healthy aging in this full article, which appears in INSIDER’s Healthy Aging Digital Magazine.
Stephen Ashmead is a senior fellow at Balchem Corp. His area of specialty is in mineral amino acid chelates and their functions.
1. Rémond D et al. “Understanding the gastrointestinal tract of the elderly to develop dietary solution that prevent malnutrition.” Oncotarget. 2015;6(16):13858-13898.
2. Eggersdorf M et al. “Hidden hunger: Solutions for America's aging populations.” Nutrients. 2018; 10:1210-1224.
3. Baum J, Kim I, Wolfe R. “Protein consumption and the elderly: What is the optimal level of intake?” Nutrients. 2016; 8:359-367.
4. Dos Santos L et al. “Sarcopenia and physical independence in older adults: the independent and synergic role of muscle mass and muscle function.” J Cachexia Sarcopenia Muscle. 2017 Apr;8(2):245-250. DOI: 10.1002/jcsm.12160.
5. Deer R, Volpi E. “Protein intake and muscle function in older adults.” Curr Opin Clin Nutr Metab Care. 2015 May;18(3):248-53. DOI: 10.1097/MCO.0000000000000162.