Plasma antioxidants and cognitive performance in middle-aged and older adults: results of the Austrian Stroke Prevention Study.

OBJECTIVE

To study the association between cognitive status and plasma concentrations of various antioxidants in middle-aged and older individuals without neuropsychiatric disease.

METHODS

Evaluation of cross-sectional data from a cohort study.

METHODS

The Austrian Stroke Prevention Study.

METHODS

A total of 1769 subjects aged 50 to 75 years, with no history or signs of neuropsychiatric disease, selected randomly from the community register.

METHODS

The score on the Mattis Dementia Rating Scale (MDRS) was dichotomized according to age-and education-specific lowest quartile cut-off points. Reversed-phase high performance liquid chromatography measurements of the plasma concentrations of lutein/zeaxanthin, cryptoxanthin, canthaxanthin, lycopene, alpha-carotene, beta-carotene, retinol, gamma-tocopherol, alpha-tocopherol, and ascorbate were measured.

RESULTS

Individuals with MDRS results below the lowest quartile cut-off point had lower levels of beta-carotene and alpha-tocopherol than their counterparts with test performance above this limit (0.44+/-.33 micromol/L vs 0.51+/-.48 micromol/L, P < .001; and 29.50+/-7.98 micromol/L vs 30.93+/-11.10 micromol/L, P < .001, respectively). Only alphatocopherol remained significantly associated with cognitive functioning when logistic regression analysis was used to adjust for possible confounders including age, sex, month of blood sampling, years of education, smoking, lipid status, and major risk factors for stroke (P = .019).

CONCLUSIONS

These observations are compatible with the view that some dietary antioxidants may protect against cognitive impairment in older people.