Obese people may be at higher risk of dementia, new study finds
New UK research has found that being obese could increase an individual's risk of dementia later in life compared to maintaining a weight within a normal, healthy range.
Carried out by researchers at University College London, the new study looked at 6,582 people who were aged 50 years and over and were free of dementia at the start of the study.
The participants had their body mass index (BMI) measured and were categorized as being normal weight (which is a BMI of 18.5 to 24.9), overweight (BMI of 25 to 29.9) or obese (BMI of 30 or above). Their waist circumference was also recorded to measure their central obesity, defined as a circumference of 88 cm or more for women and 102 cm or greater for men.
They were then followed for an average of 11 years, during which time the researchers recorded any diagnoses and episodes of dementia.
The findings, published in the International Journal of Epidemiology, showed that the participants whose BMI was 30 or higher at the start of the study, classing them as being obese, had a 31 percent greater risk of dementia than those with a BMI between 18.5 to 24.9, which is within the normal range.
The researchers also found that there appeared to be a significant difference between obese men and women's dementia risk. While women with central obesity, as measured by their waist circumference, had a 39 percent increased risk of dementia compared to those with a normal level, the same increase in risk was not found among the men.
However, when the researchers looked at BMI and waist circumference together, they found that both male and female obese participants had a 28 percent greater risk of dementia compared to those in the normal range for both BMI and waist circumference.
"These findings provide new evidence that obesity may have important implications in terms of dementia risk," said 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."
Co-author Professor Andrew Steptoe also commented on the findings saying, "Dementia is one of the major health challenges of the 21st century that could threaten successful ageing of the population. Our findings suggest that rising obesity rates will compound the issue."
"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."