A new study from University College London suggests that maintaining a healthy weight may substantially reduce the risk of developing dementia later in life. The researchers found that obesity is associated with a higher risk of dementia for up to 15 years.
“Dementia is one of the major health challenges of the 21st century that could threaten successful aging of the population. Our findings suggest that rising obesity rates will compound the issue,” said study co-author Professor Andrew Steptoe of the UCL Institute of Epidemiology & Health Care.
“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.”
An individual with a body mass index (BMI) score of 30 or greater is considered obese. According to the study, individuals who are obese in late adulthood have at least a 31 percent higher risk of dementia compared to those with a healthy BMI score.
“These findings provide new evidence that obesity may have important implications in terms of dementia risk,” said study senior author Dr. Dorina Cadar.
“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.”
The researchers analyzed data from the English Longitudinal Study of Aging, including 6,582 adults over the age of 50.
The analysis revealed that individuals who were obese at the start of the study period had a 31 percent greater risk of dementia. In addition, women with abdominal obesity were found to have a 39 percent increased risk of dementia.
Previous research indicates that obesity increases the risk of dementia directly through its influence on cytokines and hormones derived from fat cells, or indirectly through vascular damage. There is also evidence that excess body fat may contribute to the accumulation of amyloid proteins or lesions in the brain through metabolic and vascular pathways.
“It is possible that the association between obesity and dementia might be potentially mediated by other conditions, such as hypertension or anticholinergic treatments,” explained study first author Yuxian Ma.
“While not explored in this study, the research question of whether there an interactive effect between obesity and other midlife risk factors, such as hypertension, diabetes and APOE ε4 carrier status, in relation to dementia will be investigated in upcoming work.”
The study is published in the International Journal of Epidemiology.