A physiological amount of zinc supplementation: effects on nutritional, lipid, and thymic status in an elderly population

Abstract

Forty-four institutionalized elderly subjects with body mass indexes (BMI) of either > or = 24 or < or = 21 participated in a 16-wk crossover study designed to determine the effects of low-dose zinc supplementation [306 mumol (20 mg)/d] on food intake, anthropometry, and biochemical and immunological indexes. Initial serum zinc concentrations were low in both groups and increased by approximately 20% after zinc supplementation. Zinc supplementation allowed a partial but significant restoration of serum thymulin activity and improved nutritional status (food intake and serum albumin and transthyretin concentrations) but had no effect on anthropometric indexes or serum apolipoproteins, except apolipoprotein CII and apolipoprotein CIII. After zinc supplementation, serum copper concentration decreased but there was no change in the ratio of low-density-lipoprotein cholesterol to high-density-lipoprotein cholesterol. Low-dose zinc supplementation allows restoration, at least partially, of nutritional and thymic status without the known disadvantages of high doses of zinc.

Zinc, metallothioneins and immunosenescence

“…Male Balb/c 50 (C) 18 mg as zinc sulphate Increased mean survival (40) 50 (Z) C57Bl/6 mice 8 (C) 300 mg/kg of Zn for 25 d Improved thymic output (47) 8 (Z) Table 1) in the majority of the studies, Prasad et al (49) and Boukaiba et al (50) have found an increment of thymulin activity and improvement in response to skin-test antigens and taste acuity; Bogden et al (51) have reported some benefit exclusively for increased lymphocyte mitogen proliferative response; Cakman et al (52) have found enhanced IFN-g production by leucocytes; Fortes et al (53) report an increased number of cytotoxic T lymphocytes; Hodkinson et al (54) describe no effect on some markers of immunity (natural killer cells) or inflammation (C-reactive protein), but only increased the ratio of CD4/CD8 T lymphocytes at month 6; Kahmann et al (55) report reduced levels of activated T-cells and basal IL-6 release from peripheral blood mononuclear cells and improved T-cell response. Using higher doses of zinc, 40-220 mg/d with different lengths of treatment (Table 1), Duchateau et al (56) and Sandstead et al (57) have observed an improvement in response to skin-test antigens and taste acuity; an improved delayed type hypersensitivity reaction has been also found in a limited number of subjects by Cossack (58) and by Wagner et al (59) ; Prasad et al (60) found improved IL-2 mRNA.…”

Zinc and immune function

“…Studies using low-dose supplementation of zinc alone (Boukaiba et al, 1993) or zinc associated with selenium (Girodon et al, 1999) in elderly patients, provide a significant improvement in thymic function and antibody response, respectively, after vaccination. These results suggest that these nutrients play a beneficial role, and, more particularly, that zinc improves an elderly person's resistance to infections, thereby increasing his or her immunity.…”

Zinc-mediated regulation of caspases activity: dose-dependent inhibition or activation of caspase-3 in the human Burkitt lymphoma B cells (Ramos)

“…Pharmacological Zn 2+ supplementation is not only able to restore an impaired immune response but also improve normal immune function by raising the physiological Zn 2+ serum level of 8 ± 12 mM about 10-fold to 100 mM. 11 Higher concentrations of extracellular Zn 2+ (500 ± 1000 mM) have frequently been used to block apoptosis in a variety of systems. Surprisingly, lower and more physiological concentrations of Zn 2+ (80 ± 200 mM) can induce partial death in thymocytes.…”