The January 23, 2008 issue of the Journal of the American Medical Association published the finding of Benedetta Bartali, RD, PhD, of Yale University School of Medicine and colleagues that having reduced serum levels of vitamin E, an indicator of poor nutrition, is significantly associated with a decline in physical function among men and women aged 65 and older.
The current study included 698 participants in the Invecchiare in Chianti (InCHIANTI) study of risk factors contributing to physical function decline among aging men and women living in Tuscany, Italy. Examinations of the participants were performed upon enrollment from November, 1998 through May, 2000 and tests of physical function, including walking speed, chair rises, and standing balance, were conducted. Fasting blood samples were evaluated for serum concentrations of folate, vitamins B6, B12, D, E (alpha-tocopherol), and iron. Reassessment of physical function occurred at three-year follow-up examinations which took place between 2001 and 2003.
Half of the men and women were found to have experienced physical decline at follow-up. Older age (greater than 81 years) and low vitamin E levels were the greatest predictors of physical decline. Participants whose serum vitamin E levels were among the lowest 25 percent experienced a 62 percent greater risk of physical decline than the remainder of the subjects. Having low vitamin D levels was also related to subsequent decline, but this association did not remain significant after adjusting for various factors, whereas the result for vitamin E did not appreciably change.
“The hypothesis that antioxidants play a role in the etiology of decline in physical function and disability is supported by our previous findings and other studies suggesting that oxidative stress is involved in muscle fatigue and that antioxidants play a preventive role in muscle damage by reducing oxidative injury,” the authors write. “Thus, at least 3 different mechanisms may explain the effect of low concentration of vitamin E on subsequent decline in physical function: (1) increased oxidative stress leading to muscle or DNA damage, (2) exacerbation of atherosclerosis or other pathologic conditions, and (3) development of neurodegenerative disorders.”
“The current study provides empirical evidence that a low concentration of vitamin E is associated with subsequent decline in physical function in a population-based sample of older persons living in the community,” they conclude. “Although the findings from this epidemiological study cannot establish causality, they provide a solid base that low concentration of vitamin E contributes to decline in physical function. Clinical trials may be warranted to determine whether optimal concentration of vitamin E reduces functional decline and the onset of disability in older persons with a low concentration of vitamin E.”