Zinc Intervention Strategies: Costs and Health Benefits

Zinc is required for such processes as growth, immunity and reproduction. Even in developed countries, many people have a marginal intake of zinc and several common dietary constituents can impair its absorption. Attention to the zinc nutrition of at-risk groups such as the malnourished, children, pregnant women, the elderly and immuno-compromised individuals is therefore required. New information about zinc and cancer risk has emerged. Zinc deficiency has been shown to upregulate expression of the tumor suppressor protein, p53; and impairs the DNA binding abilities of p53, NFκB, and AP-1 transcription factors. These studies suggest that a decrease in cellular zinc alone results in a loss of DNA integrity, increasing the potential for cancer risk. Conversely, zinc supplementation decreases oxidative stress and improves immune function, which may be a mechanism for its cancer preventive activity. Successful programs to increase global zinc intakes through a combination of supplementation, dietary diversification, fortification, biofortification, zinc-fertilizers, phytate reduction and/or utilizing enzymes like phytase are necessary. Industry should help to define feasible, affordable fortification strategies, identify appropriate food vehicles and fortificants, develop quality assurance systems, and implement educational campaigns to reach target populations. Fortification of staple foods, such as bread or breakfast cereals, offers a means of increasing zinc intake among the majority of the population that consume these foods and can help to ensure dietary adequacy. Biofortification is an alternate strategy for improving zinc content in staple crops, provided that there is adequate genetic biodiversity/natural variation in concentrations of relevant micronutrients. Crops with enhanced micronutrient content are most relevant to developing countries, where micronutrient deficiencies are widespread. Scientific community members need to determine the country-specific prevalence of zinc deficiency, the sensory acceptability and efficacy of the chosen zinc compound and food products, develop and implement educational campaigns to reach target populations, and verify the overall effectiveness of zinc-supplementation program(s).