June 20, 2022, 3:11 pm | Read time: 5 minutes

According to the Robert Koch Institute, about one in six children in Germany is overweight or obese. Among 11- to 13-year-olds, it’s even one in five.¹ Excess weight in childhood and adolescence can have negative health effects that persist into adulthood. An Australian study now shows that childhood obesity can affect the brain years later. In other words, the risk of cognitive decline in middle age and the likelihood of developing dementia later in life increases.

Connection Between Fitness, Obesity, and Cognitive Performance

This study is the first major investigation to establish links between objectively measured fitness, childhood obesity, and cognitive performance in middle age. More than 1,200 individuals were observed over 30 years.

Consequences of Obesity for Cognitive Performance

Cognitive decline is typically a concern for older adults. Who worries about developing dementia at 60 when they’re young? Parents should take note: If a child is overweight in their youth, it can lead to various health issues such as cardiovascular diseases, diabetes, joint problems, or depression, as well as serious long-term consequences. Researchers from Melbourne, Australia, published the results of a long-term study in the Journal of Science and Medicine in Sport, showing that overweight and unfit children also performed worse cognitively later in life.²

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Study Spanned More Than 30 Years

The long-term study began in 1985. It examined 1,244 Australian children aged 7 to 15 for fitness through strength and endurance tests. The waist-to-hip ratio was also measured. Between 2017 and 2019, participants (now aged 39 to 50) were re-evaluated and subjected to a series of computer tasks that tested brain performance.

Those with the highest levels of muscular and cardiorespiratory fitness and a lower average waist-to-hip ratio in childhood also had better processing speed and higher attention. Cardiorespiratory fitness refers to the body’s ability to supply muscles and the heart with oxygen during physical activity. The fitter participants later had better global cognitive function in middle age, meaning their general ability to handle daily activities and tasks was better developed.

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Early Obesity and Later Poorer Cognitive Health

Sporty children with strong muscles, cardiorespiratory fitness, and endurance have better cognitive health later in life. But does this automatically mean that less sporty participants have poorer cognition?

In this case, yes: Those with poorer fitness results had worse psychomotor skills and lower global cognition compared to those with the highest fitness levels and the lowest waist-to-hip ratio. Deterioration can begin as early as middle age, according to lead author Michele Callisaya from Monash University in Australia in a university statement.³ Lower performance was linked not only to cognitive impairments in middle age but also to dementia in later life.

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Preventing Excess Weight in Children

“Importantly, the study also shows that protective strategies against future cognitive decline may need to start in early childhood to build enough brain reserves against diseases like dementia in old age,” Callisaya said. This means childhood obesity should be taken even more seriously than already advised. Parents who develop strategies against obesity and low fitness early can do much for their child’s future and significantly improve cognitive performance in middle and later life. Early activity, sports, and good fitness promote a healthy metabolism–which can, in turn, reduce the risk of dementia in older age.

More on the topic

According to the study Lonely Childhood Significantly Increases Dementia Risk in Old Age

Study Overweight teenagers have an increased risk for 17 types of cancer in adulthood

The Role of Dementia in the Future

The number of dementia cases is expected to more than triple worldwide to over 150 million by 2050, according to a 2019 study.⁴ While this is primarily due to an aging population, it is also a problem rooted in unhealthy lifestyle factors. With technological advancements, people are less physically active in daily life, and much of the thinking is done for them. Smoking, obesity, and chronic high blood sugar levels also contribute to dementia, Alzheimer’s, and related conditions. Physical activity, eating plenty of fatty fish, fruits, and vegetables, and reducing fatty and sugary foods and alcohol can reduce the risk.

Sources

• 1. Robert Koch Institute (2018). Childhood Obesity: Factors in Focus.
• 2. Tait J.L, Collyer T.A., Gall S.L. (2022). Longitudinal associations of childhood fitness and obesity profiles with midlife cognitive function: an Australian cohort study. Journal of Science and Medicine in Sports.
• 3. Monash University. The “Real” 7-Up – the 30-Year Study Linking Childhood Obesity and Fitness to Midlife Cognition. (accessed June 20, 2022)
• 4. Dementia Forecasting Collaborators (2019). Estimation of the global prevalence of dementia in 2019 and forecasted prevalence in 2050: an analysis for the Global Burden of Disease Study. The Lancet Public Health.