Lower IQ, Poor Fitness in Teen Years Linked to Higher Risk of DementiaA new study of more than one million Swedish men found that those who had a lower IQ or poor cardiovascular fitness at the age of 18 suffered more often from dementia before the age of 60.

“Previous studies have shown the correlation between cardiovascular fitness and the risk of dementia in old age,” said Jenny Nyberg, Ph.D., a researcher at the Sahlgrenska Academy of Gothenburg University, who headed the study.

“Now, for the first time, we can show that the increased risk also applies to early-onset dementia and its precursors.”

The study shows that men who had poorer cardiovascular fitness when conscripted into the military were 2.5 times more likely to develop early-onset dementia later in life.

Those with a lower IQ had a four times greater risk, according to the researchers.

A combination of both poor cardiovascular fitness and low IQ correlated to a seven times greater risk of early-onset dementia, the researchers report.

The increased risk remained even when controlled for other risk factors, such as heredity, medical history, and socioeconomic circumstances, researchers added.

“We already knew that physical and cognitive exercise reduces the risk of neurological disease,” said Professor Georg Kuhn, Ph.D., senior author of the study.

“Physical exercise increases nerve cell complexity and function and even generation of new nerve cells in the adult brain, which strengthens our mental and physiological functions. In other words, good cardiovascular fitness makes the brain more resistant to damage and disease.”

“People who develop early-onset dementia are often of working age and can have children still living at home, which means the consequences for both the sufferers and their families are even more serious,” the researchers said. “Despite this, patients with early-onset dementia are a relatively overlooked group,” they added.

“This makes it important to initiate more research into how physical and mental exercise can affect the prevalence of different types of dementia,” Nyberg said. “Perhaps exercise can be used as both a prophylactic and a treatment for those in the risk zone for early-onset dementia.”

The study is published in the scientific journal Brain.

Source: Sahlgrenska Academy, Gothenburg University

Dementia brain word collage photo by shutterstock.