Coffee Drinking, but Not Smoking, Linked to Protective Effect in Late-Onset Blepharospasm

June 27, 2007 — Coffee drinking, but not cigarette smoking, may have a protective effect in primary late-onset blepharospasm, a rare type of dystonia.
Investigators at the University of Bari in Italy found individuals who drank 1 to 2 cups of coffee per day were less likely to develop the condition than those who drank less than this amount. Furthermore, there was a delay in the age of onset of the condition associated with coffee consumption — 1.7 years for each additional cup per day.
However, unlike studies of Parkinson's disease, which have linked smoking to a decreased risk for the disease, as well as in a previous study of blepharospasm, the Italian team found no significant protective effect of blepharospasm related to cigarette smoking.
"The protective effect of cigarette smoking and coffee in Parkinson's disease is well established. However, like Parkinson's, blepharospasm arises from the extrapyramidal system. In addition, there is a scarcity of information on the etiology of PD [Parkinson's disease] so we wanted to look at these lifestyle habits to see whether lifetime coffee and cigarette used influenced blepharospasm risk," principal investigator Giovanni Defazio, MD, of the University of Bari told Medscape.
The study is published in the June 19 Online First issue of the Journal of Neurology, Neurosurgery, and Psychiatry.
Smoking Conferred No Protective Effect
In this retrospective, case-control, multicenter study, the 2 lifestyle habits, coffee drinking and cigarette smoking, were examined in 166 patients with primary late-onset blepharospasm, 187 healthy population control subjects (patients' relatives), and 228 hospital control patients with primary hemifacial spasm all from 5 hospital-based movement disorder clinics in Italy.
The lifetime coffee consumption and smoking habits were determined for all participants by an expert interviewer who was not blinded to the case/control status but was unaware of the study hypothesis. All study subjects were asked about their coffee and smoking habits up to the reference age. This was the age of onset of dystonia or hemifacial spasm for case patients and hospital control patients.
A reference age was calculated for the population control subjects based on the duration of the spasms in the hospital control patients.
Study participants were also asked to estimate how many cups of coffee they drank and/or packs of cigarettes they smoked per day. Demographic and clinical information was also collected.
The investigators found that individuals with blepharospasm reported a significantly lower mean number of cups of coffee per day than hospital control patients and population control subjects, whereas there was no significant relationship with the amount smoked per day and a reduced risk for blepharospasm.
Delayed Disease Onset
"We found patients with blepharospasm drank coffee less often than controls, which suggests a strong protective effect. The other important result was the observation that for every additional cup of coffee consumed per day there was a delay in the age of onset of blepharospasm. So the higher the number of cups per day, the greater the delay in onset of the disease," he said.
According to Dr. Defazio, prevalence estimates of blepharospasm are uncertain. Available studies, he said, are biased because of a number of methodologic problems and likely provide an underestimation. However, he said, the most relevant research showed a prevalence of about 133 per 1 million population. Dystonia in general, he added, affects approximately 1000 per million population.
The protective effect associated with coffee is most likely caffeine, said Dr. DeFazio.
"The association of caffeine and BSP [blepharospasm] may be biologically plausible given the pro-dopaminergic activity exerted by caffeine through an antagonistic action on adenosine receptors. This has been called into play to explain the observed protective effect on the development of PD," the authors write.
As a result, said Dr. Defazio, adenosine receptor antagonists may effectively alleviate blepharospasm symptoms.
The team's next research steps, said Dr. Defazio, will be to determine whether coffee consumption has any protective effect in other forms of dystonia such as writer's cramp and cervical dystonia, because although these conditions differ in their clinical presentations, it is likely they have a common etiology.
"I believe our data may have implications for the understanding of the etiology and treatment of primary BSP and that future studies seeking additional environmental or genetic factors for dystonia should take the effect of coffee into account," he said.
J Neurol Neurosurg Psychiatry. Published online June 19, 2007.

Coffee Not Only Keeps Eyelids Open, It Keeps Them Still

BARI, Italy, June 21 -- Coffee drinkers with a multi-cup a day habit are at lower-risk for potentially disabling eyelid spasms than non-drinkers, but cigarette smoking was not protective, as earlier evidence suggested.
In a study comparing 166 patients who developed late-onset blepharospasm with 228 patients who had other forms of facial spasms and with 187 healthy controls, a history of coffee drinking was associated with about a 40% lower risk for eyelid spasms, reported Giovanni Defazio, M.D., and colleagues, of the University of Bari here.
The effect of coffee appeared to be dose dependent, with patients who reported drinking two or more cups a day having the greatest benefit, the authors reported in an early online release from the Journal of Neurology, Neurosurgery & Psychiatry, a BMJ specialty journal.
Patients with a heavy coffee habit also tended to have later onset of spasms, with each additional cup per day delaying onset by 1.7 years (adjusted regression coefficient 1.73; P=0.001), the investigators found.
Although copious coffee-drinking is usually associated with the jitters, the calming effect on eyelid spasms may be related to caffeine, the authors suggested, adding that they were not able to compare caffeinated coffee with decaf, owing to the infrequent use of the latter in Italy.
In an earlier study, the same group had found evidence that cigarette smoking might have a protective effect against late-onset dystonia. However, "owing to multiple testing, this study was liable to a higher risk of false results than ad hoc hypothesis testing studies," the authors wrote.
"In addition, the study did not examine some potential confounders, including coffee. We therefore designed an ad hoc case control study investigating the role of lifetime coffee and cigarette habits on the risk of primary blepharospasm."
The authors looked at information on age at disease onset, smoking and coffee drinking status at the reference age, and the average number of cups of coffee drunk and/or cigarettes smoked per day.
They found that in an unadjusted logistic regression analysis, both coffee drinking and cigarette smoking were inversely associated with blepharospasm risk compared with patients with other types of facial spasms or controls.
But in an analysis adjusted for age, gender, referral center, disease duration, years of schooling, and ever coffee drinking/cigarette smoking, the authors found that smoking was no longer significantly associated with a lower risk for blepharospasm, whereas coffee-drinking remained significant.
In the adjusted analysis, the odds ratio for coffee consumption in cases versus hospital controls was 0.37 (95% confidence interval 0.20 to 0.67) and compared with population-based controls the odds ratio for coffee consumption was 0.44 (95% CI 0.23 to 0.85).
They noted that the evidence for coffee's protective effects against blepharospasm are supported by their observation of a dose-response effect, and delayed onset of spasm among patients with a multi-cup per day habit.
"Several studies have shown a similar dose-related protective effect of coffee in Parkinson's disease," they wrote. "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 acknowledged that the study was limited by the retrospective case control design, which may be subject to recall or reporting bias.
The study was supported by a 40% grant from the Italian Ministry for Education, University and Research. The authors declared that they had no competing interests. Primary source: Journal of Neurology, Neurosurgery & PsychiatrySource reference: Defazio G et al. "Influence of coffee drinking and cigarette smoking on the risk of primary late onset blepharospasm: evidence from a multicenter case control study."
J Neurol Neurosurg Psychiatry doi: 10.1136/jnnp.2007.119891