High vitamin E plasma levels may be protective against cognitive impairment and dementia, the InChianti study shows.
Researchers examined 1,033 participants (56% women) aged 65 and over in two Italian communities in the Chianti region near Florence in an effort to clarify the conflicting role of antioxidants in maintaining cognitive ability in the elderly.
Functional ability was assessed using the Activities of Daily Living (ADL) scale and the Instrumental Activities of Daily Living (IADL) scale, with cognitive function and dementia ascertained using the Mini Mental State Examination (MMSE). Follow-up interviews were also conducted with those participants who reported problems in the ADL and IADL scales, according to Antonio Cherubini, M.D., of the Institute of Gerontology and Geriatrics, Perugia, Italy, and his colleagues (Neurobiology of Aging 2005;26:987–94).
Participants were subdivided into three categories: 807 participants with MMSE scores greater than 23 were deemed to have normal cognitive function; 168 with scores less than 23 and/or any degree of disability in ADL or IADL determined to be attributable to cognitive problems were deemed cognitively impaired; and 58 participants were diagnosed as having a dementia syndrome.
Vitamin E plasma concentration was measured using high-performance liquid chromatography. The plasma level was strongly correlated with total cholesterol and triglycerides, and weakly correlated with dietary vitamin E intake.
In a multivariate analysis of the participants fully adjusted for age, gender, lipid levels, education, total energy intake, vitamin E intake, and smoking, those individuals in the bottom tertile of vitamin E plasma levels were at significantly higher risk not only of being demented (OR 2.6, 95% CI) but also of having impaired cognitive function (OR 2.2, 95% CI), compared with the highest vitamin E tertile, according to the report.