Coenzyme Q10 and Dementia: A Systematic Review

It is well known that coenzyme Q₁₀ (CoQ₁₀) has important antioxidant properties. Because one of the main mechanisms involved in the pathogenesis of Alzheimer's disease (AD) and other neurodegenerative diseases is oxidative stress, analysis of the concentrations of CoQ₁₀ in different tissues of AD patients and with other dementia syndromes and the possible therapeutic role of CoQ₁₀ in AD have been addressed in several studies. We performed a systematic review and a meta-analysis of these studies measuring tissue CoQ₁₀ levels in patients with dementia and controls which showed that, compared with controls, AD patients had similar serum/plasma CoQ₁₀ levels. We also revised the possible therapeutic effects of CoQ₁₀ in experimental models of AD and other dementias (which showed important neuroprotective effects of coenzyme Q₁₀) and in humans with AD, other dementias, and mild cognitive impairment (with inconclusive results). The potential role of CoQ₁₀ treatment in AD and in improving memory in aged rodents shown in experimental models deserves future studies in patients with AD, other causes of dementia, and mild cognitive impairment.