A large-scale analysis of medical records for nearly two million British people over up to two decades, by Oxon Epidemiology and the London School of Hygiene and Tropical Medicine, has discovered surprising relationships between obesity / body mass index (BMI) and dementia risk.
The evidence indicates that underweight people are most at risk of developing dementia. Underweight people have a 39% higher risk of dementia than people with what is considered to be a healthy weight. People who are overweight, by contrast, appear to benefit from an 18% reduction in dementia risk, and this seemingly rises to 24% for those considered obese.
Reference: Qizilbash, N. Gregson, J. Johnson, ME. [et al] (2015). BMI and risk of dementia in two million people over two decades: a retrospective cohort study. The Lancet Diabetes & Endocrinology. April 9th 2015.
Middle-age spread ‘seems to reduce dementia risk’. NHS Choices Behind the Headlines, April 10th 2015.
Being overweight ‘reduces dementia risk’. BBC Health News, April 10th 2015.