Immunity Benefits of Zinc as We Age
Low zinc can threaten your immune system. As we age, our immune system is more susceptible to weakening, which can lead to serious, even fatal, health problems. In order to limit this decline, it is essential to maintain healthy immunity through a diet rich in phytochemicals and essential nutrients.
Eating healthy reduces vulnerability to respiratory illness because many micronutrients work to support proper immune function. Phytochemicals from colorful vegetables, fruits, and other plant foods also have anti-microbial and immune-boosting effects.
Maintaining Zinc Levels as We Age
Diminished immune function increases the susceptibility to pneumonia and influenza, in addition to heightening the risk for developing autoimmune diseases and cancers. Maintaining an adequate zinc status can limit the decline in immune function that often occurs with age.
Several studies have found the elderly to be at risk for zinc deficiency. Fewer than half of older adults in the United States consume adequate zinc. The problem is compounded because there may be a loss of absorption efficiency as we age.
Research suggests that, especially for older people, maintaining an adequate zinc status may be of particular importance for preventing pneumonia. For the elderly, infectious diseases such as pneumonia, are major—yet preventable—forms of illness. In a study of older adults in nursing homes, those with normal serum zinc had a lower incidence of pneumonia and half as many antibiotic prescriptions compared to those with low serum zinc.
Studies involving older people supplementing with zinc suggest that improving zinc status improves immune system function and resistance to infection. In a 2007 study, adults ages 55 to 87 had lower plasma zinc and higher oxidative stress and inflammatory markers compared to younger adults. Half of the older adults took zinc supplements for 12 months, and the other half took a placebo. The rate of respiratory infections and markers of inflammation and oxidative stress were lower in the zinc group than in the placebo group.
A 2016 study in the American Journal of Clinical Nutrition gave zinc-deficient nursing home residents a zinc supplement or a placebo daily. After three months, the zinc group increased their serum zinc and T cell numbers.
For those who are not eating an optimal diet to strengthen their immune function, immunity starts to diminish around ages 60 to 65. But even those who are eating a proper diet may need zinc supplementation. Zinc needs are estimated to be about 50 percent higher for those who follow a completely plant-based diet due to reduced bioavailability from plant foods. Phytate, which is an antioxidant compound found in whole grains, legumes, nuts, and seeds, prevents the absorption of certain minerals, including zinc. In addition, other minerals such as iron and calcium interfere with zinc absorption. Copper also competes with zinc for binding proteins inside the body’s cells.
How Zinc Boosts Immunity
Although zinc has many different functions in the body, the characteristics of immunity malfunction as we age are similar to those of zinc deficiency, implying that diminishing zinc could be a major factor in the age-associated decline of immune function. Zinc is essential for DNA synthesis and cell proliferation, and for this reason, highly proliferating cells, like immune cells, are dependent on an adequate supply of zinc. Growth or function of different types of immune cells, like macrophages, neutrophils, natural killer cells, T cells, and B cells is impaired by zinc deficiency.
In addition to its role in the immune system, zinc also reduces oxidative stress, plays a structural role by stabilizing proteins, regulates the expression of many genes, and drives hundreds of chemical reactions in the body. Zinc also is required for neurotransmitter release in the brain and insulin packaging and secretion.
Maintaining your zinc status could be a key to living a long, healthier life by optimizing the function of your immune system. Zinc, coupled with eating a nutrient-dense, plant-rich (Nutritarian) diet, slows the aging process and lowers your risk for pneumonia and other life-threatening infections.
- Barnett JB, Dao MC, Hamer DH, et al: Effect of Zinc Supplementation on Serum Zinc Concentration and T Cell Proliferation in Nursing Home Elderly: A Randomized, Double-Blind, Placebo-Controlled Trial. Am J Clin Nutr 2016;103:942-951.
- Barnett JB, Hamer DH, Meydani SN: Low Zinc Status: A New Risk Factor for Pneumonia in the Elderly? Nutr Rev 2010;68:30-37.
- Briefel RR, Bialostosky K, Kennedy-Stephenson J, et al: Zinc Intake of the U.S. population: Findings From the Third National Health and Nutrition Examination Survey, 1988-1994. J Nutr 2000;130:1367S-1373S.
- Meydani SN, Barnett JB, Dallal GE, et al: Serum Zinc and Pneumonia in Nursing Home Elderly. Am J Clin Nutr 2007;86:1167-1173.
- Prasad AS, Beck FW, Bao B, et al: Zinc Supplementation Decreases Incidence of Infections in the Elderly: Effect of Zinc on Generation of Cytokines and Oxidative Stress. Am J Clin Nutr 2007;85:837-844.