Obesity and overweight increase the risk of many health conditions. A new study from Canada has found that excess body weight may also affect cog-nitive function, with inflammation possibly playing a role. People with excess fatty tissue gained lower scores for processing speed in cognitive tests.
Physical exercise, which increases blood flow to the brain, may help limit cognitive impairment even in those with a high body mass index (BMI).
It is widely known that excess body weight is associated with many health conditionsTrusted Source. Now, researchers have found an association between adi-posity — having too much fatty tissue in the body — and cognitive impairment.
At the start of a new study, which appears in JAMA Network OpenTrusted Source, Canadian researchers determined the adiposity of more than 9,000 partici-pants.
They measured both total body fat and visceral adipose tissue (VAT) — the fat that predominantly sits around organs in the abdominal cavity. Previous studiesTrusted Source have associated VAT, or visceral fat, with increased morbidity and a higher mortality risk. Visceral fat increases the risk of many conditions, such as:
This latest study suggests that excess fat may have mental as well as physical effects. All participants undertook two cognitive tests — the Digital Symbol Substitution Test (DSST) and the Montreal Cognitive Assessment (MoCA) — to assess a range of cognitive functions.
The researchers adjusted the scores for cardiovascular risk factors, educational level, and MRI-detected vascular brain injuryTrusted Source, which is known to be associated with cognitive impairment.
The researchers found that higher total body fat and higher VAT were both significantly associated with lower DSST and MoCA scores. The association was greater on the DSST, which assesses processing speed, than on the MoCA, which is a multidimensional cognitive test.
Compared with those in the lowest quartile (25%) of adiposity, the performance of those in the highest quartile was equivalent to an additional 3 years of cognitive aging.
“It is well-known that greater adiposity and body fat are associated with increased cardiovascular risk factors and that those are associated with increased risk of cognitive decline. This cross-sectional study found that excess adiposity was a risk factor for reduced cognitive scores, independent of cardiovas-cular risk factors, educational level, and MRI-detected vascular brain injury.”
