A child’s level of physical fitness, and whether or not they are obese, may have significant repercussions for cognitive health in middle age, according to a new study conducted by a team of researchers at Monash University. The study, which appears in the Journal of Science and Medicine in Sport, followed over 1,200 children for 30 years, beginning in 1985. While the authors noted that the benefits of childhood fitness and healthy weight for a range of adult health outcomes are well-established, few large-scale studies have established any potential impact on cognition in later years.
 
At baseline, the children were between 7 and 15 years old, and were followed all the way to 2017-2019 in order to evaluate if early activity levels, fitness, and metabolic health may protect against dementia in older years. The children, who took part in a study called Australian Childhood Determinants of Adult Health, were assessed for measures of cardiorespiratory function, muscular power, muscular endurance, and waist-to-hip ratio.
 
The participants were followed up with at an average age of 44 (ages 39-50) and tested for cognitive function scores through a series of computerized tests. The researchers found a significant association between high levels of cardiorespiratory/muscular fitness, and a lower waist-to-hip ratio, with better midlife scores in tests of processing speed and attention, as well as global cognitive function.
 
Importantly, this association was not impacted by a number of confounding factors, such as academic ability and socioeconomic status at childhood, or by smoking or alcohol consumption later in life.
 
Because decline in cognitive performance can begin as early as middle-age, and lower midlife cognition has been associated with a greater likelihood of developing mild cognitive impairment and dementia in older age, it is important to detect factors that may protect against cognitive decline later in life, according to study co-lead Michele Callisaya, associate professor at the National Center for Healthy Aging.
 
“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,” she said. “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.”