New research into body mass index and cognitive decline suggests a connection between a stable BMI and less cognitive decline in older adults.
A new study published in Alzheimer’s and Dementia, the Journal of the Alzheimer’s Association, found that people with significant changes in their BMI – the common estimate of body fat based on a person’s height and weight – tended to have faster cognitive decline.
The study was published last month and included subjects enrolled in the National Alzheimer’s Coordinating Center’s Uniform Data Set. The study included more than 15,000 subjects, all of whom were at least 60 years old and were not diagnosed with any forms of dementia at the beginning of the research.
While research on the relationship between BMI and cognitive decline is relatively new, previous studies have shown a correlation between an abnormal BMI and worse cognitive decline in old age. The study’s authors acknowledged as much.
“The aging research community has successfully identified diverse risk factors for late-life cognitive impairment,” reads the study’s introduction. “Consistent evidence associates body mass index (BMI), the most common measure of global adiposity, in midlife, with poor cognitive outcomes in late life.”
However, this new research concludes that, regardless of a patient’s starting weight, major fluctuations in BMI are a factor in cognitive decline. Specifically, faster cognitive decline was observed in people whose BMI fluctuated by or more than 5% over an average of five years.
According to HealthDay, the study was not designed to show how the outcomes are related, only to establish that a link exists.
“There’s something about maintaining weight and BMI that seems to reflect some health resilience,” the study’s lead author, Michal Schnaider-Beeri, PhD, told HealthDay. She called for more research into why the BMI fluctuations were correlated with cognitive decline.
Previous research, including a study published last year in The Journals of Gerontology, has singled out high BMI as a risk factor for cognitive decline and, specifically, Alzheimer’s disease.
“Body mass index (BMI) is a risk factor for Alzheimer’s disease (AD), although the relationship is complex,” reads the opening line of that study’s abstract. “Obesity in midlife is associated with increased risk for AD, whereas evidence supports both higher and lower BMI increasing risk for AD in late life.”