Survey of neuroleptic prescribing in residents of nursing homes in Glasgow: Table 1

Poor cognitive performance has been associated with increased mortality in several studies of elderly people, but the underlying mechanisms are unclear * In this prospective study of 921 elderly people cognitive impairment was a strong predictor of death from ischaemic stroke * Low vitamin C intake and low plasma ascorbate concentrations were also important risk factors for death from stroke * Cognitive performance was poorest in people with the lowest vitamin C status * A high vitamin C intake may protect against both cognitive impairment and cerebrovascular disease showed that intake of the antioxidant vitamin C was a strong predictor of subsequent death from stroke.8This finding, together with the known link between atherosclerosis and cognitive impairment, suggests that subclinical deficiency of vitamin C may be a determinant rather than a consequence of impaired cognitive function in elderly people.Declining cognitive function and cerebrovascular disease are both common in old people.The results of this study tend to support the view that a considerable proportion of cognitive decline in the elderly popu- lation is vascular in origin.They also suggest that a high vitamin C intake, perhaps by an antiatherogenic mechanism, protects against both cognitive impair- ment and cerebrovascular disease.This may have important implications for prevention.We thank the Department of Health for allowing us to use data from the 1973-4 Department of Health and Social Security's nutritional survey.We are grateful to David Coggon and Clive Osmond of the MRC's environmental epidemiology unit for advice and to Paul Winter for help with computing.The DHSS survey was coordinated by the late Professor A N Exton-Smith, and the biochemical analyses were carried out by Joan Stephen.