Efecto del consumo de un complemento alimentario en la concentración plasmática de cinc en adultos mayores residentes en Santiago de Chile

Abstract

Background: Zinc intake is well below recommendation among Chilean free living elderly adults of low socioeconomic level. Aim: To assess the effect of the consumption of a food supplement on plasma zinc concentrations in elderly adults (EA). Material and Methods: Ambulatory EA (≥70) with controlled type 2 diabetes mellitus or high blood pressure, ascribed to public family health centers were studied. They were separated in a control and intervention group, without blinding techniques. The intervention group consumed daily 50 g of a special nutritional supplement prepared as a soup or porridge, provided by the Government, for 3 months. The control group did not receive the supplement. A good compliance with the supplement was defined as a consumption of 7 portions per week. A fasting venous blood sample was obtained to determine plasma zinc at the beginning and end of the study. Results: Forty three supplemented EA aged 76±5 years (21 women) and 31 non supplemented EA aged 78±5 years (20 women), completed 3 months of follow up. Mean compliance with the supplement was 40.5% (95% confidence intervals (CI) 40.3-40.6%). General characteristics of the study subjects upon recruitment were similar, except for the literacy that was higher in the intervention group. We fitted a multiple linear regression model which explained 39% of the variance, where the consumption of the nutritional supplement increased the concentration of plasmatic zinc by 4.14 μg/dL (95% CI 0.25-8.02) (p <0.037), after controlling for sex, age, energy, vitamin E and calcium consumption. Conclusions: The consumption of a food supplement significantly increased plasma zinc concentrations in Chilean elderly adults.