In the middle of the debate of whether coffee is good or bad for our health, Italian researchers come with a pro argument. They say people who drink coffee are less prone to developing blepharospasm, an involuntary eye spasm which makes patients blink uncontrollably, which may become a severe vision impairment. The effect is linked to coffee intake: one to two cups daily proved to induce the desired effect.

The age for the onset of the blepharospasm was also delayed by coffee drinking, with 1.7 years for each supplementary daily cup. Previous researches have shown that smoking protects against blepharospasm development, but this Italian research did not come with any argument to sustain a significant protective effect.

Blepharospasm induces uncontrollable eyelid contractions; in severe cases, this involuntary blinking can lead the patients functionally blind (despite intact eyeballs) as they cannot impede closing their eyes.

The research pool included 166 patients with primary late onset blepharospasm, 228 patients with hemifacial spasm (a muscle spasm that starts with the eyelids and spreads to the other muscles of the face) and 187 subjects, relatives of patients, acting as a control group. The volunteers were investigated if they had ever drunk coffee or smoked, what were the quantities (in cups/day and/or packs/day) and for how long. The patients were asked for the age of the emergence of the muscle spasms. Regression analysis was employed for assessing the relationship between coffee drinking and smoking in the development of blepharospasm.

"Our findings raise doubt about the association of smoking and blepharospasm but strongly suggest coffee as a protective factor. The most obvious candidate for the protective effect is caffeine, but the low frequency of decaffeinated coffee intake in Italy prevented us from examining the effects of caffeine on blepharospasm." said the authors.

The researchers believe that caffeine inhibits the adenosine receptors, just as it happens in its protective effect against Parkinson's disease. "Considering that the caffeine content of a cup of Italian coffee (60-120 mg) is similar to the average content of a cup of American coffee (95-125 mg), the protective effect on the development of blepharospasm might be exerted at caffeine doses greater than 120-240 mg, comparable with the caffeine doses suggested to be protective in Parkinson's disease," they said.