People over age 65 who consume more than three alcoholic drinks daily face double the risk of developing involuntary tremors as nondrinkers, according to researchers who studied elderly drinkers in Spain.

HealthDay News reported April 8 that the study also found that the risk of developing involuntary (essential) tremor rose 23 percent for every year in which study subjects had three or more drinks daily. Risk of tremor also was elevated among those who drank less daily, but still drank regularly.

Researchers noted that alcohol is a known brain toxin, and that tremor is thought to be caused by damage to brain cells called Purkinje cells.

The study was published online in the Journal of Neurology, Neurosurgery, and Psychiatry.