Several studies in the United States, Canada and Europe have shown a decline in the incidence of Alzheimer’s disease. But important risk factors for dementia, such as middle-aged obesity, are on the rise. The decline in the incidence of dementia is therefore puzzling. In a paper published in the journal Journal of Alzheimer’s Disease, University of Toronto professor Esme Fuller-Thomson and her student, Judy Deng, offer a possible explanation: A decline in dementia rates could be lifelong lead. Exposure of the results of intergenerational differences.
Leaded gasoline was a major source of lead contamination from the 1920s to the 1970s. As it is phased out, the level of lead in the blood of the body begins to decline. Studies have shown that people born before 1925 are exposed to twice as much lead in their lifetime as people born between 1936 and 1945.
Lead is a well-known neurotoxin, and animal studies have linked exposure to lead to dementia in individual studies.