Nutritional Challenges as We Age

Posted: February 25, 2021

Aging and Nutrient Absorption

As we age, there are a number of natural physiological changes experienced in gastrointestinal (GI) function. In 2015, a scientific research team led by D. Rémond, conducted an extensive reviewof these GI changes1. They wanted to gain a better understanding of the GI tract in the elderly in order to find dietary solutions to help prevent malnutrition. Some of their findings included that:

  • Starting in the mouth, there seems to be a decrease in saliva production.
  • While  there does not seem to be a decrease in acid production in the stomach, there is often an increase in the incidence of stomach infections which can decrease stomach acid production.
  • There are decreases in the production of digestive enzymes in the intestine.

With these gastrointestinal tract changes, there are associated consequences to the absorption of nutrients that we ingest. Saliva is loaded with enzymes that help in the breakdown of nutrients to make them more usable and available in the body. So with the decrease in saliva production, there may be challenges impacting optimal nutrition starting right in the mouth. Decreased stomach acid can affect bioavailability of nutrients. Decreases in the production of digestive enzymes may result in lowered nutrient availability as well as changes in the endocrine system which impacts how we feel about food and satiety.

Aging populations are at risk for many nutrient deficiencies. There are metabolic challenges that require older individuals to take specific steps to help ensure that that they get adequate nutrition.

To support healthy aging, many circumstances call for the use of dietary supplements to deliver optimal levels of key nutrients. For minerals, highly bioavailable and tolerable forms such as chelates offered by Albion® Minerals can be beneficial in helping to meet these challenges.

Increased Need for Calcium and Iron as We Age

As we age, our bodies undergo significant changes affecting nearly all organs and processes. Many people experience decreased motility, loss of muscle mass and strength (sarcopenia), cognitive decline and declines in bone mineralization and joint health.

Both the loss of bone mineralization and the increased risk of catastrophic bone fracture are major concerns in the elderly. As we get older it also takes longer to heal and recover from injury and bodily insults, and changes in gastrointestinal function can make it more difficult to utilize nutrients that are consumed. Adequate calcium nutrition is of vital importance to bone mineralization, yet recent NHANES data from the elderly population showed that more than 50% of failed to consume adequate levels of calcium.

Additionally, in a double isotopic study, researchers found years ago that as both men and women age, the fractional intestinal absorption of calcium decreases2. They showed that there was a significant inverse relationship between age and calcium absorption. The data suggests that there may be a 2-3-fold decrease in calcium absorption2. While the decrease in calcium absorption may be secondary to decreased intestinal sensitivity to 1,25-dihydroxyvitamin D, changes in hormonal levels, or other reasons3, the net result is lower absorption of calcium.  

Studies over the years have summarized that dairy products with their high calcium content not only provide a good source of calcium, but can also provide other nutrients that are beneficial to calcium nutrition and a number of physiological processes4. An additional nutritional strategy would be to choose supplemental calcium sources that are highly bioavailable such as calcium bisglycinate5.

Iron deficiency anemia is commonly thought of as the most prevalent nutritional disease in the world. This is common through all ages of life, and the risk can increase in the elderly. In the United States, it is approximated that 10% of the population ages 65 and older are anemic, and this percentage doubles at age 856. There are variable causes of iron deficiency anemia that are incident with aging. In one study of over 600 subjects ages 21-94 with iron deficiency anemia, researchers found that 51% of the subjects had gastrointestinal diseases that were not associated with bleeding7. They also determined the diseases common in the older subjects included hernia, gastric and colon cancer, and colonic vascular ectasia. Hypochloridria, perhaps due to stomach infections, may also be a factor in developing iron deficiency anemia as pH is an important factor in its absorption4,6. Determining iron deficiency in elderly is difficult because there is often chronic inflammation.

Some consequences of iron deficiency in the elderly include clear associations with disability and declining physical performance, possible increased risk of ischemic heart disease, and increase risk of symptoms of depression7. The potential consequences of iron deficiency warrants paying close attention to iron status as we age. The changes in the gastrointestinal tract that affect nutrient absorption make it worthwhile to consider supplementation with highly bioavailable sources of iron.

Zinc and Healthy Aging

Zinc is an essential mineral that has many functions in the body, including providing support for cell replication, brain health, and immune function. While these are important concerns as we age, it has been suggested that in adults ages 60-65 zinc intake is below 50% of the recommended daily allowance8. Accordingly, there is a concern regarding the potential of developing a zinc deficiency in the elderly due to both inadequate consumption and absorption. Some factors that might lead to inadequate intake include avoiding zinc rich foods, increased consumption of refined wheat products, and increased consumption of high fiber foods also rich in phytates9. Gastrointestinal changes associated with aging can have an effect on the proper absorption of nutrients, including zinc.

In the elderly, the immune system has a gradual decline, particularly in adaptive response. This is further complicated by physiological changes associated with aging, increased oxidative stress and other lifestyle factors10. To combat oxidative stress, a steady supply of antioxidants, including zinc, are needed. Zinc deficiency can lead to disruption of several immune pathways. It can result in a reduction in thymus activity and its hormones, a reduction in effectiveness of T helper cells, detrimental changes in interleukins and deterioration of innate immune cell function9.  

Zinc may also play a role in cognitive neuronal processes. In an update on zinc and depression, Nowak, et al, suggested that there may be a benefit to zinc supplementation in antidepressant therapy through action upon the N-methyl-D-aspartate (NMDA) receptor11. Other studies have indicated that zinc deficiency increases neuronal apoptosis, causing deficiency in learning and memory9. Links have been made between zinc and Parkinson’s disease and Alzheimer’s disease, with attention to the role of a zinc-copper interaction with the latter9.

Numerous studies and reviews indicate that zinc supplementation particularly in the elderly, may be beneficial to supporting immune function, cognitive function, and lowering risk of age-related diseases8,9,11.

References:

  1. Rémond, D., Shahar, D. R., Gille, D., Pinto, P., Kachal, J., Peron, M.-A., et al.. Understanding the gastrointestinal tract of the elderly to develop dietary solution that prevent malnutrition. Oncotarget, 2015;6(16):13858-13898.
  2. Alevizaci CC, Ikkos DG, Singhelakis P. Progressive decrease of true intestinal calcium absorption with age in normal man. J Nuclear Med 1973;14(10):760-762.
  3. Pattanaungkui S, Riggs BL, Vergey AL, Vieira NE, O’Fallon WM, Khosla S.  Relationship of intestinal calcium absorption to 1,25-dihydroxyvitamin D [1,25(OH)2D] levels in young versus elderly women: evidence for age related intestinal resistance to 1,25(OH)2D action.  J of Clin Endocrinol Metabol.  2000;85(11):4023-4026.
  4. Rémond, D., Shahar, D. R., Gille, D., Pinto, P., Kachal, J., Peron, M.-A., et al.. Understanding the gastrointestinal tract of the elderly to develop dietary solution that prevent malnutrition. Oncotarget, 2015;6(16):13858-13898.
  5. Heaney RP, Recker RR, Weaver CM.  Absorbability of calcium sources: the limited role of solubility.  Calcif Tissue Int. 1990;46:300-304.
  6. Fairweather-Tait, S. J., Wawer, A. A., Gillings, R., Jennings, A., & Myint, P. K. Iron status in the elderly. Mechanisms of Ageing and Developmen. 2014;136-137(100):22-28.
  7. Annibale B, Cpurso G, Chistolini A, D’Ambra G, DiGiulio E, Monarca B, DelleFave G. Gastrointestinal causes of refractory iron deficiency anemia in patients without gastrointestinal symptoms. Am. J. Med. 2001;111:439–445.
  8. Mocchegiani, E., Romeo, J., Malavolta, M., Costarelli, L., Giacconie, R., Diaz, L.-E., & Marcos, A. Zinc: dietary intake and impact of supplementation on immune function in elderly. AGE. 2013;35:839-860.
  9. Cabrera AJR. Zinc, aging, and immunosenescence: an overview.  Pathobiol Aging Age-related Dis. 2015;5:25592.
  10. Maggini S, Pierre A, Calder PC.  Immune function and micronutrient requirements change over the life course. Nutrients 2018;10:1531-1557.
  11. Nowak, G., Szewczyk, B., & Pilc, A. Zinc and depression. An update. Pharmacological Reports. 20056;57:713-718.