Our ability to absorb zinc is reduced with age, and many older people lack zinc, even though there is plenty of zinc in the diet they eat. The trace element is involved in over 1,000 enzyme processes and is also an important antioxidant that protects our cells. Even minor zinc deficiencies can speed up ageing processes and contribute to skin and hair problems, infections such as bladder infections, chronic inflammation, elevated blood pressure, cancer, and other diseases. People with unhealthy diets, vegetarians, vegans, and older people are at particularly vulnerable. Certain types of medicine that many seniors take can also increase the risk of a zinc deficiency.
All cells in the body need zinc, a nutrient that is involved in well over 1,000 enzyme processes. Zinc also supports several different transport proteins in the cell membranes that make sure that the right genes are expressed at the right moment. Therefore, zinc is of vital importance to a host of physiological processes, including the brain and nervous system, the immune defense, skin, hair, and wound healing, the circulatory system, blood sugar regulation, and fertility. Zinc is also a powerful antioxidant that protects cells against oxidative stress caused by free radicals, which are aggressive molecules that play a role in the majority of diseases. Smoking, exposure to environmental toxins, and the use of certain types of medicine increase the free radical burden, but free radicals are also a natural byproduct of our own respiration, and the number of free radicals increases with age. It is therefore essential to have enough protective antioxidants like zinc to help the body ward off these harmful compounds.
We only take up around 10-30 percent of the zinc from the food we eat, and that amount decreases with age
Zinc deficiencies are linked to premature ageing and many diseases
A study that is published in Nutritional Biochemistry shows the biological mechanisms that are responsible for age-related zinc deficiency. The study also reveals how such deficiencies can increase the risk of chronic inflammation, which is linked to a host of conditions, including auto-immune diseases, cardiovascular disease, diabetes, and cancer.
The study was conducted at the Linus Pauling Institute at Oregon State University and OSU College of Public Health and Human Sciences. According to the scientists, it is particularly important for older people to get enough zinc, as they do not absorb zinc all that well from their diets and therefore need more than the officially recommended intake for this nutrient.
Zinc deficiency is widespread – especially among older people
An estimated 40 percent of American seniors lack zinc, and the figure among seniors in Europe is probably similar. Around two billion people worldwide are believed to be zinc-deficient. But the serious consequences of this deficiency are an overlooked problem, and rather than deal with the underlying cause, doctors use medicine to treat the different complications that follow in the wake of a zinc deficiency.
Zinc deficiency increases inflammation, which is the common thread in most diseases
The above-mentioned study was carried out on lab animals. The scientists could see that several zinc-containing transport proteins did not function properly in the ageing animals. The animals showed several signs of being zinc-deficient and had increased inflammatory response, even though their diets contained sufficient quantities of zinc. When the animals were supplemented with an amount of zinc that was 10 times higher than their normal need, the inflammatory response decreased to levels that are normally observed in young, healthy animals. As mentioned earlier, zinc also protects the body against oxidative stress and DNA damage, but only if zinc levels are adequately high.
Problems in most elderly people and age-related disease
The number of older people in western countries is on the rise, and according to Emily Ho, who is the lead investigator behind the study, old people are particularly sensitive to zinc deficiencies for a number of reasons. Firstly, many old people have limited appetites. Secondly, their zinc absorption is reduced. Thirdly, eating too much calcium from dairy products and supplements can also reduce the uptake of zinc. And finally, alcohol abuse, diuretics, antacids, ACE inhibitors, plus diabetes and other diseases can also impair the uptake and utilization of zinc.
Although older people generally do not absorb zinc all that well and perhaps even take medicine that can interfere with their zinc utilization, the official recommendations (RI – or Reference Intake) are the same as for younger people. The researchers therefore suggest that recommendations be looked at and adjusted correspondingly.
Zinc sources and supplementation
Based on this study and what science already knows about zinc, the researchers recommend that older people increase their zinc intake from dietary sources and from supplements. We get zinc from fish, shellfish, meat, dairy products, nuts, kernels, and beans. Zinc from animal sources is absorbed better than zinc from plant sources.
With regard to zinc supplements, many preparations contain inorganic sources such as zinc sulfate or zinc oxide, which the body does not absorb all that well. Always study the label and stick to sources like zinc gluconate and zinc acetate that are organic zinc forms, which are easy to absorb and utilize.
The European Food Safety Authority (EFSA) has set the upper safe intake limit for adults and pregnant women at 25 mg daily. It is perfectly safe to consume large quantities of zinc from e.g. oysters or supplements for a short period of time.
Zinc content in mg per 100 grams of food
Oysters (raw), 84
Inflammatory response under zinc deficiency is exacerbates by dysfunction of the T helper type 2 lymphocyte-M2 macrophage pathway. Immunology. Apr 2019.
Luke Maxfield, Jonathan S. Crane. Zinc Deficiency. NCBI March 18, 2019
Claudia J Stocks et al. Uropathogenetic Escherichia coli employs both evasion and resistance to subvert innate immune-mediated toxicity for dissemination. Proceedings of the National Academy of Sciences, 2019
Clintoria R Williams et al. Zinc deficiency Induces Hypertension by Promoting Renal Sodium Reabsorption. American Journal of Physiology – Renal Physiology. 2019
Carmen P. Wong el al. Increased inflammatory response in aged mice is associated with age-related zinc deficiency and zinc transporter dysregulation. The journal of Nutritional Biochemistry. 2012
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