This review of the literature was conducted to assess dietary zinc
intake among the African elderly, discuss the potential impact of
current levels of zinc intake on their health, and to recommend
strategies for improving their dietary zinc intake. As zinc plays an
ubiquitous role in human metabolism, determination of its dietary
intake among African elderly is important from a health standpoint, if
the consequences of widely reported deficiency are to be mitigated.
Animal meats and seafood are rich sources of zinc, with nuts and
legumes being relatively good plant sources. Zinc bioavailability is
relatively higher in animal foods due to absence of inhibitors of zinc
absorption and the presence of cysteine and methionine, which improve
its absorption. Zinc in plant-based foods is less bioavailable for
human metabolism due to presence of chelators, phytates and dietary
fibre, which inhibit absorption. Individuals at the greatest risk of
zinc deficiency include infants and children, pregnant and lactating
women, patients being fed intravenously, malnourished individuals
including those with protein-energy malnutrition and anorexia nervosa;
others are individuals with chronic or persistent diarrhoea,
malabsorption syndromes, those with alcoholic liver disease, sickle
cell anemia, strict vegetarians, and the elderly aged 60 years and
over. A reduced capacity to absorb zinc, increases the likelihood of
disease states that may adversely alter zinc utilization, and increased
use of drugs that increase zinc excretion, may all contribute to
increased risk of mild to moderate zinc deficiency in the elderly.
Also, in situations of diminished access to adequate and balanced
diets, health care and good sanitation, the likelihood of developing
mild to moderate zinc deficiency is high among poor African elderly.
Due to the consequences of impaired immune system function in zinc
deficiency in the elderly, it is critical to maintain an adequate zinc
intake by this group. Despite mild zinc deficiency being unlikely to
lead to severe zinc deficiency in individuals without a genetic
disorder, zinc malabsorption or conditions of increased zinc loss such
as severe burns can also result in mild to severe zinc deficiency.
Diets for poor African children, pregnant and lactating women, and the
elderly, are deficient in zinc. This is mainly due to low food intake,
relatively lower intake of animal foods and high phytate and fibre
content of the staple plant-based foods. Fortification of staples and
inclusion of inexpensive and available animal protein sources, in
plant-based diets for the elderly can increase their dietary zinc
intake