World-first study links childhood obesity to lower cognition in midlife
A landmark study from researchers in Australia has established the first significant links between childhood obesity and cognitive ability in midlife, with the authors suggesting this relationship may have ties to one's risk of dementia. The research tracked subjects over a 30-year period and found that a higher level of physical performance as a child correlated with better cognition in middle age, and by extension points to lifestyle interventions that may help protect against dementia from early in life.
The research was led by scientists at Melbourne's Monash University and involved more than 1,200 subjects. In 1985, when the participants were between seven and 15 years old, researchers assessed their fitness levels through measurements of cardiorespiratory performance, muscular power and endurance, and waist-to-hip ratio.
Another round of assessments was made between 2017 and 2019, when the subjects were aged 39 to 50, this time with a focus on cognitive ability. This involved computerized tests on attention, memory and global cognition, which enabled the scientists to tease out some fascinating insights.
The scientists found that those with the highest levels of cardiorespiratory fitness, muscular performance and lowest waist-to-hip ratios way back in 1985 when they were children had higher cognitive function when they reached middle age. According to the team, this constitutes the first demonstration of such a link, and feeds into our growing understanding of early onset dementia and cognitive impairment in later life.
Research is beginning to build around how shifts in cognitive behaviors can act as early warning signs for dementia, with studies uncovering telltale signs in everything from driving behavior, and daytime napping habits, to our susceptibility to depression. Studies have also shown how this age-related decline might be tracked through biological markers, including red blood cell counts and changes to the gut microbiome.
In light of this increasing understanding of the relationship between midlife cognition and dementia, the authors of this new study suggest the findings hint at lifestyle interventions from a young age that can protect against cognitive decline and disease risk later in life (in addition to the other health benefits of active lifestyles).
"Developing strategies that improve low fitness and decrease obesity levels in childhood are important because it could contribute to improvements in cognitive performance in midlife," said study author Associate Professor Callisaya. "Importantly the study also indicates that protective strategies against future cognitive decline may need to start as far back as early childhood, so that the brain can develop sufficient reserve against developing conditions such as dementia in older life."
The research was published in the Journal of Science and Medicine in Sport.