Relationship between nutrition and dementia in the elderly.

The complexities of physiologic interactions between the nutritional status of the aged and the incidence of dementia in the elderly should be obvious from this partial survey of the field. Investigations aimed at delineating the role of individual nutrients in mentation among the elderly are extremely difficult to design and perform. However, the potential for practical applications of the results is indeed very high. The studies discussed in this article permit the following conclusions. Although many attempts have been made to enhance average life expectancy through nutritional manipulation, no such panacea currently exists. There is a well-documented decrease in caloric intake among the elderly. However, this does not seem to put them at any higher risk of developing overt deficiencies of specific nutrients. The elderly population in this country has a strong tendency to consume nutritional supplements, with vitamins C and E being the most popular. It is unknown at present whether this practice has any health value. Several attempts have been made to alter the course of dementia in the elderly through nutritional means. Attempts to ameliorate the symptoms of Alzheimer's disease through use of choline and lecithin have been overwhelmingly unsuccessful. The postulate that aluminum toxicity is an etiologic factor in this disease remains unproven, and therapies with chelating agents are not now advisable. Vitamin B12 has to be seriously considered as a causative factor in dementia; it is hoped that methods to test vitamin B12 nutriture in humans that are both more reliable and more capable of revealing marginal deficiency states will emerge. Although folic acid is intimately related biochemically and nutritionally to vitamin B12, its potential role in normal mental function remains largely unknown. Clearly, when considering nutrition and dementia in the elderly, there are many areas that still require thorough scientific investigation. Hopefully, the future will see an increase in research activity, resulting in answers to many of the questions posed in this paper.