surprising large study - underweight, overweight and obesity and alzheimer's risk
BBC:
"The team at Oxon Epidemiology and the London School of Hygiene and Tropical Medicine analysed medical records from 1,958,191 people aged 55, on average, for up to two decades.
Their most conservative analysis showed underweight people had a 39% greater risk of dementia compared with being a healthy weight.
But those who were overweight had an 18% reduction in dementia - and the figure was 24% for the obese.
"Yes, it is a surprise," said lead researcher Dr Nawab Qizilbash.
He told the BBC News website: "The controversial side is the observation that overweight and obese people have a lower risk of dementia than people with a normal, healthy body mass index.
"That's contrary to most if not all studies that have been done, but if you collect them all together our study overwhelms them in terms of size and precision." " [1]