How does a person’s weight influence their risk for dementia? A macro study carried out by the London School of Hygiene & Tropical Medicine (United Kingdom) has evaluated the relationship between body mass index and the risk of dementia, concluding that obesity can actually be a protective factor against this disease while underweight people may be at higher risk. The study has been published in The Lancet Diabetes & Endocrinology journal.
Alzheimer’s is the most common form of dementia and some of the factors that increase the risk of suffering from it have been well studied: family history and advanced age. Now, in this latest study, the researchers examined the records of the Clinical Practice Research Datalink database , which has the medical records of 9% of the population of England. The follow-up was carried out for a period of 20 years. The adults included in the study had a mean age of 55 years at the beginning of the study and a Body Mass Index (BMI) of 26.5, that is, overweight. Over the next 9 years, 45,507 people were diagnosed with dementia.
The results revealed that compared to adults who had a healthy BMI (between 20 and 25), those who were underweight (BMI less than 20) during middle age were 34% more likely to be diagnosed with dementia . This increased risk was maintained for the next 15 years.
In addition, the risk of dementia decreased steadily if her BMI increased. Thus, compared to participants who had a healthy BMI, those who were severely obese (a BMI greater than 40) were almost 30% less likely to develop dementia.
“Our results also open up an intriguing new avenue in the search for protective factors for dementia – if we can understand why people with a high BMI have a lower risk of dementia , it is possible that at the end of the line, researchers may be able to use this information to develop new treatments for dementia ”explains Stuart Pocock, leader of the study.





