Obesity linked to higher risk of dementia

New research suggests that weight management could play a significant role in reducing the risk of developing dementia, after finding that obesity is linked to a higher risk of the condition up to 15 years later.

The research, led by University College London and published in the International Journal of Epidemiology, indicate that people who are obese in late adulthood face a 31% increased risk of dementia than those whose body mass index (BMI) is within the ‘normal’ range, and also that the risk may be particularly high for women.

The research team looked at data from 6,582 people in a nationally representative sample of the English population aged 50 years and over, from the English Longitudinal Study of Ageing.

They found that people whose BMI was 30 or higher at the start of the study period had a 31% greater risk of dementia, at an average follow-up of 11 years, than those with BMIs from 18.5-24.9, and that women with abdominal obesity had a 39% increased risk of dementia compared to those with a normal level.

This was independent of their age, education, marital status, smoking behaviour, genetics (APOE ε4 gene), diabetes and hypertension – and yet this association was not found among the male participants, the researchers noted.

Dr Dorina Cadar, UCL Institute of Epidemiology & Health Care, and senior author of the study, said the findings provide new evidence that obesity may have important implications for dementia risk.

“Both BMI and waist circumference status should be monitored to avoid metabolic dysregulations. Hence, reducing weight to optimal levels is recommended by adopting healthy and balanced patterns of eating, such as the Mediterranean diet, appropriate physical exercise and reduced alcohol consumption throughout the course of the entire adult life span.”

“By identifying factors that may raise dementia risk that are influenced by lifestyle factors, we hope that a substantial portion, but admittedly not all, of dementia cases can be prevented through public health interventions,” added co-author Professor Andrew Steptoe, from the UCL Institute of Epidemiology & Health Care and director of the English Longitudinal Study of Ageing.

The study was funded by the National Institute on Aging of the National Institutes of Health, with support from the Economic and Social Research Council, the Office for National Statistics and the National Institute for Health Research.