Zinc deficiency and its link to age-related diseases
As the elderly population grows, so does the number of people affected by infections, cardiovascular disease, diabetes, dementia, arthritis, cancer, and other degenerative conditions. These diseases appear to be characterized by a dysregulated immune system and chronic inflammation, which can damage and destroy cells via free radicals. If left unaddressed, this dysregulation also increases the risk of reduced quality of life and premature death. According to a review article published in Immunity & Ageing, many older adults are deficient in zinc, which is an essential nutrient for proper immune function and a powerful antioxidant that helps protect cells. But why is zinc deficiency so widespread, and how can we ensure adequate intake?
The aging process involves changes in the immune system that increase the risk of infections and chronic inflammation - features that underlie most chronic diseases. This age-related decline in immune function makes the body more vulnerable and is referred to as immunosenescence. This condition especially weakens the innate immune system, which normally protects us against most pathogens without symptoms. Immunosenescence also impairs the innate immune system’s crucial communication with the adaptive immune system, which is more specialized, produces antibodies, and has memory.
In fighting viruses, bacteria, and other pathogens, the immune system relies on inflammatory processes that must be both effective and tightly regulated. If not, the risk of infections rises, and illnesses such as influenza and COVID-19 may become life-threatening due to the body’s overreaction – better known as hyperinflammation
Many chronic conditions are also associated with a low level of persistent, subclinical inflammation, including cardiovascular disease, diabetes, dementia, and cancer. Similarly, autoimmune diseases such as rheumatoid arthritis are characterized by chronic inflammation.
Overall, it appears that these disturbed inflammatory processes play a key role in the development of many age-related diseases, which is why the term inflammaging is often used.
One of the main reasons why hyperinflammation and chronic inflammation are so harmful is that the immune system uses free radicals as part of its defense. These highly reactive molecules can cause serious damage to cholesterol and healthy cells if not properly controlled.
Because diet plays such a major role, the authors of the review took a closer look at zinc, especially since deficiency is so common.
Zinc strengthens and regulates the immune system in multiple ways
Zinc is involved in hundreds of enzymatic processes essential to overall health. According to the review article, zinc supports the immune system in the following ways:
- Influencing DNA synthesis
- Supporting the rapid proliferation of white blood cells during acute infections
- Maintaining the function of innate immune cells, including neutrophils, macrophages, and NK cells
- Supporting the function of T and B cells in the adaptive immune system
- Regulating inflammatory responses
- Acting as a key antioxidant (SOD) that protects healthy cells from damage caused by free radicals and oxidative stress
The review also explores zinc’s role in various age-related diseases, including infections (such as COVID-19), type 2 diabetes, AMD (age-related macular degeneration), atherosclerosis and other cardiovascular diseases, depression, and wound healing.
It’s worth adding that zinc is also crucial for the activation and utilization of vitamin D by forming so-called “zinc fingers” in the vitamin D receptors on cells. This function is important because vitamin D has other vital roles in supporting immune health.
Zinc sources and reasons for widespread deficiency
Zinc is found in shellfish (especially oysters), liver, meat, eggs, and fish. Plant-based sources include nuts, seeds, and legumes, but zinc is more easily absorbed from animal products. Since the body cannot store zinc, a daily intake is essential.
The recommended intake for adults is 10 mg per day. However, according to the European Food Safety Authority (EFSA), an estimated 75 percent of people aged 65–80 do not get enough zinc due to unbalanced diets or loss of appetite.
Moreover, many older individuals have impaired absorption or utilization of zinc due to low stomach acid or the use of medications such as antacids, antibiotics (like tetracyclines), blood pressure medications (ACE inhibitors), and diuretics.
Even mild deficiencies - not just severe deficiency - can negatively affect immune function and other processes.
If dietary intake is insufficient, a high-quality and well-absorbed zinc supplement can be a practical solution. During infections or chronic inflammation, zinc requirements may be higher.
The upper safe intake level is 40 mg per day, but short-term therapeutic doses of 75–100 mg daily may be used. Long-term high-dose supplementation is not recommended, as excessive zinc can interfere with the absorption of iron and copper.
References:
Michale Tobias Schulz, Lothar Rink. Zinc deficiency as possible link between immunosenescence and age-related diseases. Immunity & Ageing 2025
Ashton Amos, Mohammed S. Razzaque. Zinc and its role in vitamin D function. Current Research in Physiology. 2022
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