Previously, some studies have suggested that abnormal lipid metabolism may contribute to the pathology of Alzheimer's Disease.  Kensuke Sasaki, from Kyushu University (Japan), and colleagues studied cholesterol levels among 2,587 people, ages 40 to 79 years, who had no signs of Alzheimer's Disease. Then they examined 147 autopsied people who died after a long observation period (10 to 15 years). Of those, 50 people, or 34%, had been diagnosed with dementia before death. The autopsies looked for plaques and tangles in the brain, both known to be trademark signs of Alzheimer's disease.  People with high cholesterol levels, defined by a reading of more than 5.8 mmol/L, had significantly more brain plaques when compared to those with normal or lower cholesterol levels. A total of 86% of people with high cholesterol had brain plaques, compared with only 62% of people with low cholesterol levels. The researchers conclude that: “The results of this study suggest that dyslipidemia increases the risk of plaque-type pathology.”