Hong Kong doctors advise caution as study links obesity to lower dementia risk
Surprised scientists and local doctors advise caution and more research
People who are obese in middle age are less likely to develop dementia later, according to a large and long-term study whose findings challenge the prevailing wisdom. But local doctors cautioned that the unexpected finding shouldn't encourage people to stay or become too heavy.
The data also indicated that being underweight between the ages of 40 and 55 correlated with a higher risk, researchers found.
Surprised by the potential protective effect of obesity, the British research team cautioned against jumping to conclusions and said further investigation into the reasons would be needed for the study, published by The Lancet Diabetes and Endocrinology on Thursday.
The team delved into a British database with almost two million patients who were older than 40 and whose body mass index was recorded between 1992 and 2007. They later compared the patients' BMI and the number who developed dementia.
With every increasing BMI category, they saw a correlating decline in incidence of dementia, "with very obese people (BMI over 40) having a 29 per cent lower dementia risk than people of a healthy weight", the team said.
Meanwhile, underweight people, who had a BMI below 20 in this study, had a 34 per cent higher risk of dementia.