Older people who are thinner or are losing weight quickly have a higher risk of losing weight, according to a new study.
Study author Tiffany Hughes of the University of Pittsburgh School of Medicine explained in the latest issue of Neurology that people with a lower body mass index at the beginning of the research were 79 per cent more likely to develop dementia.
She and her counterparts studied 1,836 Japanese Americans in Washington State with an average age of 72, finding that dementia sometimes develops in the brain for decades before symptoms develop.
Ms Hughes added: "These findings likely reflect that process.
"In middle age, obesity may be a risk factor for dementia, while declining weight in late life may be considered one of the first changes from the disease that occurs before it actually affects a person's memory."
Neurology is the official publication of the American Academy of Neurology, which looks into conditions such as Alzheimer's disease and dementia.
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