Morning coffee does more than give you a caffeine kick - Study

A study recently published in the Psychopharmacology journal revealed that caffeine consumption can actually be helpful for your visual function as it increases alertness and detection accuracy for moving targets. Caffeine also helps improve your reaction times, it stated.

Researchers from Waterloo's School of Optometry & Vision Science and the University of Granada collaborated for the study.

While caffeine is known to increases the velocity of rapid-eye movements, the researchers wanted to further investigate the effects of caffeine ingestion on dynamic visual acuity, i.e. ability to detect and recognize small details under moving conditions.

Dynamic visual acuity skills are important in many daily like crossing a busy intersection or finding something on a shelf while walking through the aisles of a grocery store, the researchers said.

Effects of caffeine intake

In the study, a group of participants ingested a caffeine capsule (4mg/kg) while the other group ingested a placebo capsule. Using a computer-based test, their dynamic visual acuity skills were measured before and 60 minutes after the ingestion.

According to the researchers, those who had ingested the caffeine capsules showed significantly greater accuracy and faster speed when identifying smaller moving stimuli.

"Our findings show that caffeine consumption can actually be helpful for a person's visual function by enhancing alertness and feelings of wakefulness," said Dr. Kristine Dalton of Waterloo's School of Optometry & Vision Science, as quoted by ScienceDaily.

"This is especially true for those critical, everyday tasks, like driving, riding a bike or playing sports, that require us to attend to detailed information in moving objects when making decisions," the co-author of the study added.

Too much caffeine is bad for health

Experts say caffeine increases alertness by blocking the effects of adenosine, a brain chemical that makes you feel tired, and activating adrenaline, the "fight-or-flight" hormone associated with increased energy. However, at higher doses, these effects may lead to anxiety and nervousness.

Caffeine helps you stay awake but too much caffeine may interfere with your sleep. According to studies, higher caffeine intake may increase the amount of time it takes to fall asleep as well as decrease total sleeping time.

What is safe?

According to Mayo Clinic, up to 400 milligrams (mg) of caffeine a day (which is roughly four cups of brewed coffee) appears to be safe for most healthy adults. But caffeine is not good for children. Pregnant women or those who are trying to become pregnant and who are breast-feeding are recommended to limit their caffeine intake to less than 200 mg daily.