Long distance drivers who consume caffeine, such as coffee or energy drinks, have a significantly lower risk of being involved in a crash than those who do not.

The finding came from new research conducted by a team of experts from Australia and was published in the British Medical Journal (BMJ).

The authors said:

“Long distance drivers routinely experience monotonous and extended driving periods in a sedentary position, which has been associated with wake time drowsiness, increasing the likelihood of crashing.”

Caffeine is one of the most popular stimulants around the world that has been proven to help workers become more alert during shifts. A report from 2010 demonstrated that shift workers who consume caffeine make fewer errors.

However, the quantity and and quality of sleep can also be impacted by caffeine intake. Although prior research has indicated that caffeine is a successful way to make people more alert, there have been no studies showing the association between caffeine and the likelihood of injury.

Therefore, the Australian scientists set out to examine the impact caffeine has on the probability of a crash among long distance commercial vehicle drivers.

The trial was conducted in Western Australia and New South Wales between 2008 and 2011, and consisted of long distance drivers whose vehicle mass was 12 tons or more. The researchers compared 530 drivers who crashed their vehicle while driving long distance (cases) with 517 drivers who did not crash in the past year (controls).

Forty-three percent of drivers reported trying to stay awake by consuming caffeinated substances, such as:

  • coffee
  • tea
  • caffeine tablets
  • energy drinks

This indicates that drivers drivers are making behavioral adjustment to help control their tiredness, according to the lead author Lisa Sharwood (The George Institute, University of Sydney).

Sharwood explained:

“This may seem effective in enhancing their alertness, but it should be considered carefully in the context of a safe and healthy fatigue management strategy; energy drinks and coffee certainly don’t replace the need for sleep.”

On average, case drivers were about 2 years younger than controls and had a higher probability of having had at least one crash in the previous 5 years.

Although the controls had more experience driving and usually drove longer distances than case drivers, they got fewer hours of sleep each night and found it more challenging to stay awake while driving.

Results were adjusted for factors such as:

  • kilometres driven
  • night driving schedules
  • sleep patterns
  • symptoms of sleep apnea
  • breaks taken

The scientists discovered that the drivers who consumed caffeine had a 63% lower risk of crashing than drivers who did not consume any caffeinated substances.

There was an association between heavy cigarette smoking alone with a crash risk, however, this did not remain after adjusting for many confounding variables.

Having a crash in the past 5 years increased the likelihood of having another crash by 81% and this stayed significant after adjustments.

The experts concluded that consuming caffeine “can significantly protect against crash risk for the long distance commercial driver”, which has “important implications for the improvement of fatigue management strategies for this and similar populations.”

The authors added that the advantage is only useful for a short time, therefore, they suggest having frequent breaks, napping, and proper working hours.

Written by Sarah Glynn