How unwittingly wise it appears Bob Dylan might have been when singing that ditty - 'One more Cup of Coffee for the Road' - on the 1970 album desire.
The possible link between coffee consumption and a lower risk of getting Type 2 Diabetes is well reported, but this new study led by Harvard School of Public Health (HSPC) researchers claims to break new ground.
The team say they do so by being the first to show that changes in coffee consumption habits can affect diabetes risk within a relatively short timescale; they also found that those who cut their coffee consumption by more than a cup per day increased their type 2 diabetes risk by 17%.
Drinking more coffee cuts risk in 'relatively short' time
"Our findings confirm those of previous studies that showed that higher coffee consumption was associated with lower Type 2 diabetes risk," said Shilpa Bhupathiraju, lead author and research fellow in the Department of Nutrition at HSPH.
"Most importantly, they provide new evidence that changes in coffee consumption habit can affect type 2 diabetes risk in a relatively short period of time," he added.
The scientists analyzed data on caffeinated and decaffeinated coffee, and caffeinated tea consumption from 48,464 women in the Brigham and Women's Hospital-based Nurses' Health Study (1986-2006), 47,510 women in Nurses' Health Study II (1991-2007), and 27,759 men in the Health Professionals Follow-up Study (1986-2006).
They evaluated subjects' diets every four years via questionnaire, and those who self-reported type 2 diabetes filled out additional questionnaires. 7,269 cases of type 2 diabetes were reported.
Don't just drink coffee - watch your weight, and exercise!
The results showed that those who upped their coffee intake by more than one cup/day (median change: 1.69 cups, one cup of coffee: 8oz, black, or with a small amount of milk and/or sugar) over four years had a 11% lower risk of getting Type 2 Diabetes than those who did not change their coffee-drinking habits.
Subjects who cut their daily coffee consumption by more than one cup (median: 2 cups/day) were found to have a 17% higher risk of diabetes; changes in decaffeinated coffee consumption and caffeinated tea consumption were not associated with any changes in diabetes risk.
Co-author Frank Hu said the results showed that coffee offers health benefits for most people, but warned that coffee was only one factor among many that affected diabetes risk.
"More importantly, individuals should watch their weight and be physically active," he added.
Title: ‘Changes in Coffee Intake and Subsequent Risk of Type 2 Diabetes: Three Large Cohorts of US Men and Women’
Authors: Bhupathhiraju, S., Pan, A. Manson, J.E, Willett, W.C., Van Dam, R.M., Hu, F.B.
Source: Diabetologia, Published online April 24 2014, DOI 10.1007/s00125-014-3235-7