Life Extension Magazine March 2014
Getting Back To Basics ... How Low-Cost Zinc Helps Combat Deadly Immunosenescence
By Heath Ramsey
Zinc is required by the body for more than 2,000 transcription factors involved in gene expressions of various proteins.1 What this means in everyday language is that thousands of essential biological functions are dependent on zinc.
The medical community has known of zinc deficiency for more than 50 years, but the health impact of this crucial mineral has been largely ignored by global health organizations. Extensive scientific inquiry has made it clear that nutritional deficiency of zinc is widely prevalent and its morbidities are severe.1
Overwhelmingly, the elderly are deficient in zinc1. Because zinc governs so many biological functions, a simple zinc deficiency can affect multiple facets of health and development.1 The result is a decline in our body’s vigilant immune system, opening the door for an onslaught of numerous diseases. A zinc deficiency contributes to atherosclerosis, cancer, neurological disorders, autoimmune diseases, and other age-related chronic conditions.2
One target that researchers are focusing on is the fact that a zinc deficiency can cause your immune system to decline, a phenomenon known as immunosenescence. This decline in immunity places older adults at increased risk for a range of almost every serious disease, from infections and cancer.3
Fortunately, supplementing with the proper amount of zinc can provide life-saving benefits against the diseases of aging. Studies have shown that zinc supplementation in the elderly can restore normal function of the killer cells that attack virally-infected and cancerous cells as well as boost the immune system’s anti-aging mechanisms.4-6
Adequate zinc levels have been found to reduce the risk of infection as well as decrease oxidative and inflammatory markers.7
Even if zinc levels are adequate, supplementing with zinc may offer additional protection against cancer. In animals with normal zinc levels, the number of experimentally-induced tumors was 28% lower when the animals were given a modest zinc supplement.8
There is no reason that this readily available and inexpensive mineral should not be an essential component of your personal health program against the dangers of immunosenescence.
Immunosenescence: The Waning Of The Immune System
Zinc deficiency is rampant among older adults. As with so many other essentials, zinc levels decrease with age.9 But that’s only part of the problem.
Another major cause is that people simply don’t get enough of this nutrient on a daily basis. The government’s minimum recommended daily allowance (RDA) of zinc is just 15 mg. Yet 35% to 45% of people older than 60 don’t even get half of that.10-13
Scientists now believe that zinc deficiency plays a direct role in the aging of the immune system, known as immunosenescence.14
In immunosenescence, there’s a decrease in the immune system cells that normally identify and destroy abnormal cells (such as bacteria, virally-infected cells, and cancer cells).15 That leaves older adults increasingly vulnerable to infections and cancers, while making vaccinations less effective as well.16
Immunosenescence also increases the frequency and severity of autoimmune disorders (such as rheumatoid arthritis and lupus), in which the immune system attacks and destroys healthy body tissue.16 In addition, immunosenescence leads to the loss of regulatory control, which adds to the total burden of inflammation in the body, leading to atherosclerosis, osteoporosis, and further heightening the risks of cancer.14,17
Battle Immunosenescence With Zinc
Immunosenescence is a very complex process that is still being understood by researchers. However, what scientists are now realizing is that the immune system in the elderly is the result of a continuous remodelling process.18 That means it’s possible to fight against this phenomenon of aging—for which zinc is a vital component. There are remarkable similarities between immunosenescence and zinc deficiency, similarities so striking that scientists now believe they can’t be coincidental.19,20
A deficiency in zinc reduces the activity of the thymus gland, which prevents the production of essential “killer” T-cells. This shifts the balance to “suppressor” cells that reduce the immune response.21
Low zinc levels also increase the occurrence of autoimmunity and excessive inflammation (as is seen in immunosenescence).20 Even borderline low levels of zinc can impair immune functioning and decrease the response to vaccinations.19,21 While inadequate zinc is not likely to be the only cause of immunosenescence, it appears to be one of the main contributors.
What this means to you is that by restoring zinc levels to those found in younger people, we may be able to slow immunosenescence and protect ourselves against cancer, infection, autoimmunity, and chronic inflammation.21
Zinc supplementation in the elderly has been shown to confer the following benefits:
- Restore normal function of the killer cells that go after virally-infected and cancerous cells.4,5
- Boost the stress response of white blood cells from older adults, providing an immune system anti-aging mechanism.6
- Boost the immune response to vaccines, which are becoming increasingly vital to protecting older adults from dangerous infections.5,22
- Improve cellular immunity and increase survival rates in older mice.19,23
Zinc supplementation is so widely recognized as essential to healthy immune system support that it now figures broadly in international health programs aimed at reducing the death tolls from diseases such as severe diarrhea, malaria, and tuberculosis.24-27
Zinc Battles Infections
Infections, especially those of the respiratory system, are a serious threat to the health of adults over 60 years old. Supplementing with zinc can help lower the risk of these dangerous infections in older adults.
One study showed that a daily 45 mg dose of zinc reduced the incidence of all infections, including those of the respiratory tract, in elderly adults.7 And at a very high dose (80 mg/day), zinc was found to reduce overall deaths by 27% over an median of 6.5 years.28 (Please note: Zinc should not be consumed at doses higher than 90 to 100 mg/day; at those doses it can have a negative effect on immunity and may produce urinary tract symptoms.3,29)
Two specific threats for which zinc has proven effective include pneumonia and influenza.
Pneumonia is one of the leading causes of death in the US for older adults.28 Pneumonia is prevalent in this age group precisely because of immunosenescence, the waning protection against infection. But remember, immunosensecence can be a direct result of zinc deficiency. That helps explain why people with low zinc status are even more likely to get pneumonia and to have a more severe infection, are more likely to need more antibiotics for longer, and are more likely to die from pneumonia, than are people with healthy zinc levels.29
Fortunately, studies show that simply restoring zinc to normal levels helps combat pneumonia, reducing its incidence by as much as 41%, cutting new antibiotic prescriptions nearly in half, and shortening the duration of the illness.30 In a two-year study of nursing home residents, daily supplementation with 20 mg of zinc and 100 micrograms of selenium decreased the average number of respiratory infections compared with patients taking a placebo.31
Another larger study showed that the same doses of zinc and selenium improved antibody production in elderly people after a vaccination against pneumonia-causing germs.32
Zinc has also been found to be beneficial against influenza, another infection that can be especially dangerous for older adults. Influenza virus infection of lung tissue produces rapid destruction of cells through inflammation and apoptosis.33 Zinc has the ability to directly combat these negative effects of influenza.
Lab studies show that zinc supplementation of cells in culture blocks the inflammatory response, shuts down the self-destructive cycle of apoptosis, and reduces the release of new viruses from the fragmented cells.33,34
Human studies confirm these results. Most importantly from a prevention standpoint, supplementation with zinc markedly enhances the response to influenza vaccines among older adults.23,32,35 An increase in anti-influenza antibody occurred in 87% of supplemented people and just 41% of controls. In response to the vaccine, supplemented subjects achieved white blood cell proliferation that was tenfold that of the control group.35