Dr. Yamagishi and colleagues from Japan's University of Tsukuba in a new study has used data from 6,000 middle-aged Japanese, and for the first time have been able to show that low levels of coenzyme Q10 in the blood are strongly associated to an increased risk of disabling dementia.
The researchers took the initiative to this study based on the hypothesis that because coenzyme Q10 has significant antioxidant effects, a high Q10 level ought to lower the risk of developing dementia and vice versa.
Studies on animals have previously demonstrated a potential beneficial effect of Q10 on cognitive functions, but on humans we have not previously seen clear effects of Q10 on the brain's cognitive function.
In the new study, the researchers used data from an ongoing study where the residents of a municipality had been screened for dementia, but also had their levels of Q10 in the blood measured. Out of 6000 persons the researchers selected 65 middle-aged persons with dementia who had been regularly examined at least five years before they were diagnosed with dementia. They were matched with 130 controls of similar age, sex, and data.
Alzheimer's disease inhibit mitochondria
The journal Atherosclerosis that brings the article has a comment written by cardiologist Dr. Momiyama from Tokyo Medical Center, who supply the information that patients with Alzheimer's disease have an increased level of oxidative stress in the brain that cause the accumulation of a protein called amyloid-beta, which is characteristic of Alzheimer's patients' brains. Amyloid-beta inhibits the energy-producing mitochondria's function and causes oxidative stress.
Dr. Momiyama also mentions that previous studies on dementia have shown significantly lower levels of vitamin C, -E and betacarotene than in control groups.
The researchers conclude that there is a strong correlation between high levels of Q10 in the blood and a low risk of developing dementia and vice versa. This correlation is strongest if you haven't previously had a stroke. They end up concluding that although their study needs to be confirmed by further studies, their study suggest that Q10 could be an important factor in the prevention of dementia.
Yamagishi K, et al. Serum coenzyme Q10 and risk of disabling dementia: The Circulatory Risk in Communities Study (CIRCS). Atherosclerosis. 2014;237(2):400-3.
Momiyama Y. Serum coenzyme Q10 levels as a predictor of dementia in a Japanese general population. Atherosclerosis. 2014;237(2):433-4.