Drinking one cup of caffeinated coffee daily as a replacement for other artificially sweetened beverages and sugar-sweetened beverages reduced the risk of type 2 diabetes by 9% and 17%, respectively.
USA: A recent study has claimed that greater habitual consumption of caffeinated coffee may lower type 2 diabetes risk and lead to a more favourable metabolic profile in females with a gestational diabetes mellitus (GDM) history. The study's findings were produced in The American Journal of Clinical Nutrition on 14 November 2022.

Women with a GDM history are at a greater risk of type 2 diabetes development later in life. Previous studies have assessed the connections between gestational diabetes and type 2 diabetes risk and shown separately that moderate coffee consumption can reduce mortality risk. Jiaxi Yang and the research team conducted a prospective study to examine whether greater habitual coffee consumption was linked to a lower risk of type 2 diabetes in females with a history of GDM.
For this purpose, the authors followed 4522 participants with a GDM history in the NHS II for incident type 2 diabetes between 1991 and 2017. Updation of lifestyle and demographic factors, including diet and disease outcome, was done every 2-4 years.
Collection of fasting blood samples was done in 2012–2014 from a subset of participants (n=518) not affected by diabetes to measure biomarkers of glucose metabolism (insulin, HbA1c, and C-peptide). The participants reported caffeinated and decaffeinated coffee consumption on validated FFQs. The researchers estimated the least squares mean of glucose metabolic biomarkers per coffee consumption. Adjusted HRs for the risk of T2D were calculated using multivariable Cox regression models.
The study led to the following findings:
A total of 979 study participants developed type 2 diabetes. Caffeinated coffee consumption was inversely associated with T2D risk.
Adjusted HR for ≤1, 2–3, and 4+ cups per day compared with 0 cups per day was 0.91, 0.83, and 0.46, respectively.
Replacement of 1 serving per day of sugar-sweetened beverages and artificially sweetened drinks with one cup per day of caffeinated coffee was associated with a 17% and 9% lower risk of T2D, respectively.
Greater consumption of caffeinated coffee was linked with lower fasting insulin and C-peptide concentrations.
Intake of decaffeinated coffee was not significantly related to type 2 diabetes but was inversely associated with C-peptide concentrations.
"Our findings showed that greater consumption of caffeinated coffee is associated with a lower type 2 diabetes risk and a more favourable metabolic profile in predominantly Caucasian females with a GDM history," the researchers wrote.
Reference:
Jiaxi Yang, Deirdre K Tobias, Shanshan Li, Shilpa N Bhupathiraju, Sylvia H Ley, Stefanie N Hinkle, Frank Qian, Zhangling Chen, Yeyi Zhu, Wei Bao, Jorge E Chavarro, Frank B Hu, Cuilin Zhang, Habitual coffee consumption and subsequent risk of type 2 diabetes in individuals with a history of gestational diabetes – a prospective study, The American Journal of Clinical Nutrition, 2022;, nqac241, https://doi.org/10.1093/ajcn/nqac241