5-Year Study Reveals: Driving for More Than 2 Hours Lowers Your I.Q.

They say that regular driving for more than two hours is bad for your heart, but did you know that it can also make you less smart?

This conclusion came after a five-year study of 500,000 Britons with ages ranging from 37-73. Of the 500,000 test subjects in the study, there were around 93,000 individuals who drove two to three hours each day.

According to researchers, those in this group experienced a steady decrease in brainpower over a period of five years. The decrease is more pronounced compared to those who did little or no driving at all.

Krishan Bakrania, a medical epidemiologist at the University of Leicester, thinks the reason may be that the mind is not active during those hours that people are driving.

Apart from that, one important factor to consider is the natural process of aging.

According to Bakrania, cognitive decline is measurable over five years because it can happen fast in middle-aged and older people. "This is associated with lifestyle factors such as smoking and bad diet — and now with time spent driving,” Mr Bakrania told the paper.

Aside from mental inertia and aging, mental cognition can also be affected by external factors -- such as stress.

“Driving causes stress and fatigue, with studies showing the links between them and cognitive decline,” Bakrania said.

But some may ask: doesn't it contradict some studies that say driving -- particularly operating a car -- is a complex activity that helps you exercise your brain?

A study that was published in Nature stated it this way:

“Driving is a complex everyday activity that requires multiple types of sensory processing, cost-weighted decision making, precise motor control, and other abilities. Even on an empty road, drivers must continuously operate the steering wheel and pedals in consideration of complicated vehicle dynamics. Driving is also a vigilance task, which is often undertaken for prolonged periods of time, and carries a constant risk of injury or death resulting from collisions...”

So then, if driving creates the same neural pathways that happen when a person is developing a skill (like learning to play the piano or solving a complex jigsaw puzzle), it should mean that the brain should be improving in cognition -- not worsening.

According to the Leicester research, that's only true if they're consistently doing it. What this means is that the mental boost stops once drivers don't steadily improve their driving skills -- something many middle-aged people often fall into.

So how can drivers lessen these negative effects? According to researchers, using computers daily can boost their cognitive stills, and can lessen driving's negative effects on the brain.