Young men who are unfit or have a low IQ are at increased risk of early-onset dementia later in life. Young men who are both unfit and have a low IQ are at greatest risk.
Jenny Nyberg and colleagues looked at the fitness and IQ records of over 1.1 million 18-year-old men who were conscripted into the Swedish army from 1968-2005. They then look at hospital records to see which of these men developed dementia later in life.
The men who were unfit in young adulthood were two and a half times more likely to suffer from early-onset dementia. Lower IQ put men at a four times greater risk. Young men who were both unfit and had low IQ were seven times more at risk of early-onset dementia. The risk remained elevated even when controlled for other factors, such as heredity, medical history and socioeconomic circumstances.Read more at University of Gothenburg