Recent research on hmsters suggests that too much alcohol affects the circadian rhythm, a 24 hour cycle controlled by a part of the brain that synchronises waking and sleeping with day light. Some people who drink may not respond to important light cues
such as the rising sun to remain synchronised with their natural sleep and wake cycle.
A study by Dr Christina Ruby and colleagues at Kent State University, Ohio, exposed three groups of hamsters to bright and dim lights. The water the hamsters were given to drink was either pure or mixed with 10% alcohol or 20% alcohol.
The researchers conclude that chronic drinking may affect people’s activity patterns, making drinkers less active at times of the day when they should be active and more active when they should not be, such as late at night.
The study appears in the September 2009 issue of the American Journal of Physiology Regulatory, Integrative and Comparative Physiology.