A case-controlled study, published in the journal, Atherosclerosis (2014 Dec;237(2):400-3) looked at whether coenzyme Q10 levels were related to dementia. It looked at 6000 Japanese who were between the ages of 40 and 69 at baseline. Serum coenzyme Q10 was measured in 65 incident cases of disabling dementia with dementia-related behavioral disturbance or cognitive impairment incident between 1999 and 2004, and in 130 age-, sex- and baseline year-matched controls. The researchers found that serum coenzyme Q10 was inversely associated with dementia.