According to a US study published in the scientific journal Diabetologia, increasing coffee consumption by one and a half cups a day can help reduce the risk of developing type II diabetes. The gradual decline in coffee consumption seems to have the opposite effect.
Drinking coffee and tea has been many years associated with a reduced risk for type II diabetes, but little is known about how changes in the risk of developing the disease occur by changing the amount of consumption of the two beverages.
So researchers at Harvard University’s School of Public Health, led by Drs. Frank Hu and Silpa Boupathiratzu, studied the correlations between changes in coffee and tea consumption and the risk of developing type II diabetes over a four-year period. They also looked at the relationship of diabetes depending on whether or not the coffee contained caffeine.
More specifically, they examined data from three major surveys: the Nurse’s Health Study (NHS) which involved 48,464 nurses between the age of 30-55 and for the period 1986-2006, NHS II again concerned 47,510 nurses aged 25-49 and for the period 1991-2007 and the Health Professionals Follow-up Study (HPFS), which concerned 27,759 men between the ages of 40-57 and for the period 1986-2006. In all three studies there was detailed information on diet, lifestyle, medical conditions and other chronic conditions related to participants.
The researchers eventually found 7,269 cases of type II diabetes and observed that participants who had increased coffee consumption by more than one cup a day over a four-year period had an 11% lower risk of developing type II diabetes compared to those who had not altered the amount consumed.
Participants who had reduced consumption by one cup a day or more had a 17% higher risk of developing type II diabetes. Changes in the amount of tea consumption were not associated with type II diabetes.
Those who had the highest coffee consumption, i.e. three or more cups a day had the lowest risk of type II diabetes (37%), compared to those who drank one cup or less a day.
As the scientists explain, the higher risk of developing type II diabetes associated with reduced coffee consumption may reflect a real change or may be due to the fact that people with conditions associated with type II diabetes such as hypertension, hypercholesterolaemia, cardiovascular disease and cancer may reduce coffee consumption after diagnosis.