It is commonly believed that drinking coffee, which has caffeine will act as a diuretic and cause one to lose water. If this were true it would stand to reason that drinking coffe would dehydrate the body and possibly contribute to Dry Eyes. There are now a number of studies that suggest that caffeine is not a diuretic for the average person. Wikipedia says: “Contrary to popular belief, caffeine does not act as a diuretic when consumed in moderation (less than five cups a day or 500 to 600 milligrams), and does not lead to dehydration”. In fact caffeine has been linked to many health benefits including:
- reduced risk of Alzheimers and dementia
- reduced the risk of gallstones
- reduced the risk of diabetes
This is just a few potential benefits.
Recently a Japanese study revealed that moderate caffeine intake also increased tear secretion in the eyes. The implication of this could be that by drinking coffee dry eye patients could increase the volume of tears in their eyes, which consequently might reduce their symptoms. It was clear from this study that the only parameter that was measured was tear volume and this certainly increased with caffeine. What was not clear though was whether this translated to a possible treatment. Another problem with the study was that the only population that was tested was Japanese. Possibly the results are very specific to the Japanese genetics and they might have no application to Caucasians for example.
What is amazing is that medicine is loaded with theories, which often get turned inside out when clever and accurate studies are performed. It is unlikely that caffeine will be used as a specific treatment for dry eyes as drinking coffee is common anyway. The stimulant effect for some people can be excessive and in some cases cause heart palpitations. For those that enjoy coffee, keep drinking it in moderation, as it has many benefits, while it also might help keep your dry eyes at bay.