Prior to 1993 it was not known if zinc deficiency was a clinical problem in well to do healthy elderly subjects.  Our studies in 1993 documented for the first time that 30% of healthy elderly subjects living in USA were mildly zinc deficient.  The diagnosis was made by assaying zinc in lymphocytes in as much as their plasma zinc were within normal limits.  In these two papers we documented that zinc supplementation to zinc deficient elderly subjects resulted in a significant decrease in the incidence of yearly infections, improved cell medicated immunity, decrease oxidative stress and downregulated generation of inflammatory cytokines.  In as much as increased oxidative stress and chronic inflammation have been implicated in several chronic diseases of the elderly, we hypothesize that correction of zinc deficiency in the elderly may decrease the incidences of several chronic diseases.  This hypothesis needs to be tested.

Ref.

Prasad, A.S., Beck, F.W.J., Bao, B., Fitzgerald, J.T., Snell, D.C., Steinberg, J.D., Cardozo, L.J.  Zinc supplementation decreases incidence of infections in the elderly: Effect of zinc on generation of cytokines and oxidative stress. Am. J. Clin. Nutr., 85(3)837-844, 2007.

Bao, B., Prasad, A., Beck, F.W.J., Fitzgerald J.T., Snell, D., Bao, G.W., Singh, T., Cardozo, L.J.  Zinc decreases C-reactive protein, lipid peroxidation, and inflammatory cytokines in elderly subjects: A potential implication of zinc as an atheroprotective agent. Am J Clin Nutr, 91:1634-1641,2010.