Abstract
The nutritional status of patients with senile dementia and depression and of residents in Part III accommodation, compared to community controls, were assessed. The biochemical and psychometric effects of vitamin supplementation in senile and phase-one dementia were also investigated, and the effects of folate deficiency on the in-vitro intestinal transport of tryptophan, glucose and ascorbic acid and on the histology and mitotic index of the small intestine of the rat was studied. Low ascorbic acid and folate status, and low plasma-bound tryptophan concentrations were common findings in the patients and residents. Over a third of all subjects had evidence of thiamin deficiency. With the possible exception of ascorbic acid, these findings could not be explained in terms of dietary intake data. Plasma non-esterified fatty acids and serum insulin levels, and urinary excretion of N-methylnicotinamide relative to creatinine, factors that are known to affect plasma tryptophan levels, could not explain the lower plasma-bound tryptophan found. Plasma albumin concentrations were lower in patients with senile dementia and in patients with bi-polar depression, and it is likely that this was largely responsible for the lower plasma-bound tryptophan levels noted. Plasma non-esterified fatty acid levels were lower in uni-polar depression and this may have been the determining factor for the lower plasma-bound tryptophan levels found in these patients. Evidence of hypercalcaemia was found in a high proportion of the residents of Part III accommodation and in patients with senile dementia. The importance of this finding to the mental deficit seen in the patients and in half of the residents is discussed. A high proportion of low plasma copper was also found in the residents and their controls. Vitamin supplementation in senile dementia resulted in improved biochemical status, and three of the ten patients studied showed improvement in psychological function. A greater improvement in psychometry was found in phase-one dementia. Dietary folate deficiency in rats resulted in impaired glucose absorption and a lower tryptophan concentration gradient, but ascorbic acid absorption was unaffected. No significant changes were observed in the histology and mitotic index of the small intestine, though changes in cell proliferation was indicated by a lower crypt cell/adult cell ratio in folate deficiency.