According to a new study, obesity could be a protective factor against dementia, while people who are underweight may be at increased risk.
The study, which was conducted by the researchers from the London School of Hygiene & Tropical Medicine in the UK, and published in ‘The Lancet Diabetes & Endocrinology’ journal, states that obesity may provide protection against mental decline. This challenges previous expert advice that claims individuals who are obese in the middle age have increased risks for dementia.
Stuart Pocock, professor of medical statistics from the London School of Hygiene & Tropical Medicine, and the lead author of the study, said, “Older studies that found a link between dementia and being overweight were small in scale and these may have involved a random chance factor. People like to think obesity is bad in general so there is a sort of passion to think of new handles on which to say obesity is a bad thing, and there are many health issues for which, obviously, it is. But dementia isn’t one of them. That is new information that people need to take on board.”
For their study, the researchers analyzed the medical records of almost 2 million people who were an average age of 55 at baseline and had a median body mass index (BMI) of 26.5 kg/m2, which falls into the overweight category. During the follow up period, almost 50,000 of these individuals developed dementia but those who have the highest BMI appeared to least likely suffer from the disorder.
They found that people who were underweight had 39% increased risk for dementia compared with those who had healthy weights. Those who were overweight had 18% reduced odds for the condition and the chances were 24% less for the obese.
“Being underweight in middle age and old age carries an increased risk of dementia over two decades. Our results contradict the hypothesis that obesity in middle age could increase the risk of dementia in old age,” added Pocock.