Coffee consumption does not lower insulin resistance and diabetes risk: Study

Singapore: Denying the claims that coffee consumption lowers the risk of type 2 diabetes (T2D), a new study published in the American Journal of Nutrition has found it to have no significant impact on insulin sensitivity and hence T2D.

According to the study, consuming 4 cups per day of caffeinated coffee for 24 weeks had no significant effect on insulin sensitivity or biological mediators of insulin resistance. However, it was associated with a modest loss of fat mass (FM) and a reduction in the concentrations of urinary creatinine.

The hormone insulin helps in controlling blood sugar levels in the body. Low insulin sensitivity is known as insulin resistance. With insulin resistance, the cells do not absorb as much glucose leading to excessively high blood sugar levels. This eventually can lead to type 2 diabetes, if not managed properly.

Observational studies have found coffee consumption to be associated with a lower risk of T2D. However, trials examining the effect of coffee consumption on glucose metabolism have been limited by the use of surrogate insulin sensitivity indices, small sample sizes, lack of blinding, and short follow-up duration.

• Coffee consumption did not significantly change insulin sensitivity compared with placebo (percentage mean difference in M_bw = 4.0%).


• No significant differences in fasting plasma glucose (2.9%) or biological mediators of insulin resistance, such as plasma adiponectin (2.3%), were observed between coffee and placebo groups over 24 wk of intervention.


• Participants in the coffee arm experienced a loss of fat mass (FM) (−3.7%) and reduction in urinary creatinine concentrations (−21.2%) compared with participants in the placebo arm over 24 wk of intervention.

"Coffee consumption was associated with a modest loss in body fat mass compared with the placebo beverage, and this potential impact on adiposity warrants confirmation in additional trials," the authors wrote.

The study, "The effect of coffee consumption on insulin sensitivity and other biological risk factors for type 2 diabetes: a randomized placebo-controlled trial," is published in the American Journal of Nutrition.

DOI: https://doi.org/10.1093/ajcn/nqz306