Toronto, Sep 28 (IANS): Caffeine may not be helpful in improving mobility in people with Parkinson's disease -- a disorder of the central nervous system that affects movement -- finds a study that challenges a previously known theory.

According to a previous research published in the journal Neurology in 2012, drinking three cups of coffee per day showed possible improvement in movement symptoms for the people with the disease that also includes tremors.

"Our finding revealed that caffeine cannot be recommended as therapy for movement symptoms of Parkinson's disease," said lead author Ronald B. Postuma from the McGill University in Montreal, Canada.

For the study, published in the journal Neurology, the team involved people with an average age of 62 who had been diagnosed with Parkinson's disease for an average of four years.

While some were given a 200-milligram capsule of caffeine twice daily, once in the morning and once after lunch, the equivalent of three cups of coffee per day, the other half were given placebo capsules.

There was no improvement in movement symptoms for the people who had taken the caffeine capsules compared to those who took the placebo capsules.

There was also no difference in quality of life, the researchers said.

"Caffeine, which is so safe and inexpensive, has been linked to a reduced risk of developing Parkinson's," Postuma said.

"So it was exciting to think that it could possibly help people who already have the disease."