Consuming more caffeine may help people who are suffering from symptoms of dry eye, according to a new study.
Caffeine is a naturally occurring compound found in the leaves, seeds or fruits of more than 60 plants, including coffee beans, cacao beans, kola nuts, guarana berries and tea leaves (including yerba mate and green tea). Caffeine is consumed regularly in the United States and throughout the world, as it is found in many beverages, including coffee, chocolate, some energy drinks and tea; more than seven kilograms of caffeine per person are consumed in the United States per year.
In a new study, researchers recruited 78 healthy volunteers who randomly received either capsules of caffeine or a placebo at two study sessions. After the participants consumed their capsules, the team measured their tear meniscus height (TMH), which is used to diagnose dry eye, and also collected blood samples.
The results revealed that the people who consumed caffeine had greater tear volume, compared to that of subjects who received a placebo. There was an increase in TMH in the caffeine group, suggesting that dry eye symptoms improved.
The scientists concluded that consuming caffeine may relieve dry eye symptoms. However, more high-quality studies are needed to better understand these findings.
Medicinally, caffeine may be useful as a heart stimulant and also to improve urine flow. Caffeine has been shown to affect mood, endurance, the cerebrovascular system and gastric and colonic activity. Caffeine has also been marketed as a weight loss tool and is often included in various weight loss supplements.
For more information about caffeine, please visit Natural Standard's Foods, Herbs & Supplements Database.