Positive Health Online

Abstract

SCHRAG and COLLEAGUES, (1)Department of Neurology, Yale University, New Haven, CT, USA. matthew.schrag@yale.edu conducted a review to systematically analyze available data describing markers of oxidative stress and  antioxidants in blood from subjects with Alzheimer's disease or those with mild cognitive impairment.

Background

Abnormal oxidative stress is an established feature of Alzheimer's disease, but clinical trials aiming to reduce oxidative stress have not yet proven an effective therapy for dementia patients.

Methodology

The purpose of this review is to systematically analyze available data describing markers of oxidative stress and antioxidants in blood from subjects with Alzheimer's disease or those with mild cognitive impairment to highlight potential interactions between peripheral redox changes and central nervous system pathology and contribute to the design of future clinical study. PubMed, SCOPUS and Web of Science were systematically queried to collect studies which have evaluated markers of oxidative stress, levels of antioxidants, copper, transferrin and ceruloplasmin levels in blood from subjects with Alzheimer's disease and matched controls. After application of quality measures, results were aggregated in a random effects analysis.

Results

We found that markers of lipid peroxidation are elevated in blood in Alzheimer's disease and in mild cognitive impairment, copper metabolism is dysregulated and total antioxidant capacity is decreased. While surprisingly none of the major antioxidative enzymes are significantly decreased, non-enzymatic antioxidants in blood (particularly uric acid, vitamins A, E and C, α- and β-carotene) are significantly decreased. There is significant oxidative damage in peripheral blood early in the process of neurodegeneration.

Conclusion

The authors propose that clinical studies assessing cognitive outcomes after antioxidant therapy tailor interventions to individual patients' deficiencies and confirm an improvement in an appropriate serological marker of oxidative stress. This strategy may be most effectively applied in a clinical trial of primary prevention.

References

Schrag M(1), Mueller C, Zabel M, Crofton A, Kirsch WM, Ghribi O, Squitti R, Perry G. Oxidative stress in blood in Alzheimer's disease and mild cognitive impairment: a meta-analysis. Neurobiol Dis. 59:100-10. doi: 10.1016/j.nbd.2013.07.005. Nov 2013. Epub Jul  15 2013.