During the 2012 World Congress on Prevention of Diabetes and Its Complications (WCPD), researchers highlighted the evidence linking coffee to diabetes prevention. It was stated that research has shown three to four cups of coffee per day can cut the risk of developing type 2 diabetes by up to 25%. Another study has shown that each additional cup of coffee reduces the relative risk of type 2 diabetes by seven to eight percent.
Though the correlation between coffee and diabetes prevention has been demonstrated, the researchers were careful to point out that a causal relationship has not been established. It could be that coffee drinking is associated with other habits that prevent diabetes. However, it was also pointed out that the correlation between coffee and diabetes prevention can seem counterintuitive, since coffee drinking is often associated with unhealthy habits such as smoking or low levels of physical activity.
In light of this seemingly conflicting data, the researchers propose an "Energy Expenditure Hypothesis," suggesting that caffeine stimulates metabolism and increases energy expenditure. Also, a "Carbohydrate metabolic Hypothesis" was put forward, suggesting that coffee components could influence the glucose balance in the body. Other hypotheses suggest that coffee components could improve insulin sensitivity through various mechanisms.
"A dose-dependent inverse association between coffee drinking and total mortality has been demonstrated in general population and it persists among diabetics," said Dr. Pilar Riobó Serván, a speaker at the WCPD session and associate chief of Endocrinology and Nutrition at Jiménez Díaz-Capio Hospital in Madrid. "Although more research on the effect of coffee in health is yet needed, current information suggests that coffee is not as bad as previously considered!"