May 9/Chapel Hill, N.C./Star -- Some 90% of the world’s population consumes caffeine in one form or another, but what sets apart a coffee guzzler from their cup-a-day compatriots comes down to two genes, according to a new study.
Researchers at Harvard School of Public Health, Brigham and Women’s Hospital and the University of North Carolina at Chapel Hill looked at five population-based studies that tracked the caffeine consumption of 47,000 people, over 17 years, by charting their intake of coffee, tea, soda and chocolate.