Positive Health Online

Abstract

CHARLTON and co-workers, Nutrition and Dietetics Division, School of Health and Rehabilitation Sciences, University of Cape Town, South Africa. w.scott@iafrica.com, have found lowered plasma concentrations of vitamin C but not vitamin E in dementia patients.

Background

According to the free radical hypothesis, Alzheimer's disease affects brain regions where free radical damage occurs. Antioxidant nutrients may help to protect these brain regions. This study was aimed at investigating whether antioxidant vitamin concentrations were lowered in patients with dementia and Alzheimer's.

Methodology

A case control study was conducted in 93 institutionalized subjects over 65. 15 patients with Alzheimer's and 28 patients with senile dementia were compared to 50 subjects with no cognitive impairment. Blood plasma vitamin C and E levels were measured. Dietary intake, including dietary supplements, was assessed using a 2-day plate-waste method. Cognitive function was measured.

Results

Controls had a significantly higher plasma vitamin C concentration than dementia patients (median = 0.84 mg/dl and 0.56 mg/dl, respectively; p<0.05). The dementia group were more likely to have sub-optimal plasma vitamin C levels (< 0.6 mg/dl) than control subjects (odds ratio = 2.99; p<0.05), despite having similar dietary vitamin C intakes. Plasma vitamin C was positively associated with scores in cognitive tests. No differences were found between any of the groups for either plasma or dietary vitamin E.

Conclusion

The data support the free radical theory of oxidative neuronal damage. Further investigations of whether supplementation with this vitamin may prevent or delay the progression of cognitive decline in patients with Alzheimer's and senile dementia appear warranted.

References

Charlton KE, Rabinowitz TL, Geffen LN, Dhansay MA. Lowered plasma vitamin C, but not vitamin E, concentrations in dementia patients. Journal of Nutrition, Health & Aging. 8(2): 99-107, 2004.