Zinc’s power to boost immune system in older adults

Aging causes many maladies but a common one is a weakened immune system making older adults more susceptible to infections.  The mineral zinc appears to have a significant role in staving off this potentially life-threatening occurrence.

Since low levels of zinc impair immune functioning more so in older adults, a March 2016 study in The American Journal of Clinical Nutrition looked at whether older adults living in nursing homes who already had a zinc deficiency, could be given zinc supplements to improve this problem.  Previous research has shown that 30% of nursing home residents have low blood levels of zinc.  Residents with low levels of zinc have a significantly greater risk of developing pneumonia.

The 2016 study found that residents supplemented with zinc showed an association with strengthening the function and number of T-cells.  T-cells, a part of our immune system, are a type of white blood cell circulating in our body scanning for abnormalities and infection and are essential for human immunity.  The T stands for the thymus gland of the neck where the T-cells are stored and matured. 

At baseline for this study, participants blood levels of zinc ranged from moderately to very zinc-deficient.  The residents were divided into two groups, one receiving a daily multivitamin with 30 milligrams of zinc while the other group received a placebo containing only 5 milligrams of zinc.  The study lasted for 3 months.  Even though the study was small (25 adults age 65 or older from three Boston area nursing homes), the change in serum zinc was significantly higher, by 16%, in the group receiving zinc supplementation, than in the placebo group.  The conclusion from this study was that zinc supplementation at 30 milligrams for 3 months was effective in increasing serum zinc concentrations in nursing home elderly. 

It should be noted that not all participants who were substantially zinc-deficient at baseline, saw an increase to adequate concentrations during this time.  It was surmised that it may take time to have a positive response to zinc supplementation in people who had a significant zinc deficiency. 

Another positive from this study was that zinc supplementation boosted the immune system by improving the function of T-cells.  Both the number and effectiveness of T-cells in the group receiving a zinc supplement were at a much higher level than the placebo group.

Since older adults are already at a greater risk of the incidence and morbidity from infections, it is a major health concern for this age group.  The results from this study demonstrate that zinc supplementation may help increase the immune system, reducing the likelihood of infections.

It should be noted that zinc deficiency is not just found in nursing home residents as it can also exist in older adults who live independently.  The reason why zinc deficiency is more likely in the elderly is suspected that they do not absorb or use zinc as effectively as younger adults. 

Keep in mind not all older adults need a zinc supplement.  Zinc deficiencies are actually rare in the United States but some people are more likely to have trouble getting in enough.  This would include the elderly, people with digestive disorders and vegetarians.  The Recommended Dietary Allowance for zinc in adult men is 11 milligrams each day and for adult women is 8 milligrams a day.  It is recommended no more than 40 milligrams a day of zinc should be taken as this can be harmful.  Always seek the advice and inform your physician if you are thinking of taking or already are taking any type of dietary supplement. 

The best food sources of zinc include the following:

·         Pork

·         Shellfish

·         Red meat

·         Poultry

·         Pine nuts

·         Sunflower seeds

·         Peanuts

·         Pumpkin seeds

·         Chickpeas

·         Lentils

·         Wild rice

·         Oatmeal

·         Amaranth

·         Breakfast cereals fortified with zinc