The effect of stress on the antioxidative potential of serum: implications for Alzheimer's disease

There is growing consensus in the literature that oxidation status is increased in Alzheimer's disease (AD), and that antioxidant supplementation as prevention or treatment strategy should be investigated further. In the present study the total antioxidant status (TAS) was found to be highly significantly lower in 22 AD patients (p < 0.0001) than in 22 age- and gender matched non-demented controls. The TAS was also lower than controls in 22 patients with vascular dementia, but not significantly. The increased oxidation status in AD was verified using the benzoate hydroxylation method. The origin of the enhanced oxidation status in AD has not been elucidated. To determine whether a causal effect between stress and oxidative status of serum can be demonstrated, a rat model was used with two different kinds of stressors, swim stress (exercise) and restraint stress (non-exercise stress). Following swim stress the maximum oxidative effect was observed at one hour post stress (p < 0.001). At 24 h the oxidative status had recovered significantly to below control values. Restraint stress, however, showed progressively increased oxidation which attained significance after 24 h (p < 0.005). It is postulated that stress may contribute to the higher oxidation status in AD patients.