Melatonin or treatments preserving the endogenous rythm of melatonin formation can retard the rate of ageing and the time of onset of age-related diseases. The activation of central excitatory amino acid receptors can suppress melatonin synthesis and is accompanied by a reduced detoxification rate of hydroxyl radicals. Aged animals and humans are melatonin-deficient and more sensitive to oxidative stress. New therapies investigating the effect of endogenous excitatory amino acid antagonists and stimulants of melatonin synthesis such as magnesium, may lead to therapeutic approaches for the prevention of diseases related to premature ageing. This article argues the elderly are at a greater risk of developing mineral deficiencies.
Special attention is given to the nutrients phosphorus, magnesium and zinc.
The effect of hypochlorhydria on intestinal mineral absorption is also reviewed. Risk factors for developing mineral deficiency in the elderly include decreased food intake because of decreased activity, decreased lean body mass, decreased energy needs, increased prevalence of illness, altered taste and smell, oral health problems and avoidance of certain foods. Altered mineral bioavailability includes changes in dietary patterns and mineral imbalances. Drug mineral interactions are affected by polypharmacy, diuretics, laxatives and antacids. Decreased adaptive ability, reduced gastric acid secretion, decreased intestinal absorption efficiency and decreased renal function can all alter mineral balance in the elderly.