Black coffee and green tea have no impact on your metabolic processes: KGMU study

Lucknow: Contrary to the popular belief that black coffee and green team contract blood sugar and improve insulin sensitivity, doctors at King George's Medical University (KGMU) have found that both the beverages do not have an immediate effect on how the body uses sugar from food for energy, nor do they affect how the body responds to insulin, which helps move sugar from the blood into the cells.

The study, conducted between April 2023 and March 2024, looked at the impact of these drinks on glucose metabolism and insulin sensitivity.

Titled, "Effect of Black Coffee and Green Tea on Plasma C-Peptide Levels in Apparently Healthy Adults," the research was published in Oct 2024 in the International Journal of Research in Medical Science.

The study included 140 healthy participants aged 20 to 30 years. They were divided into three groups: one group consumed black coffee, another green tea, and the third group had lukewarm water as a control. The researchers measured the participants' plasma C-peptide levels, a marker used to study insulin function, over 21 days.

The results showed no significant changes in plasma C-peptide levels in any of the groups. The research was led by Dr Anupam Mittal, a junior resident at KGMU, with guidance from Prof Shraddha Singh, a faculty member in the physiology department.

Dr Mittal explained that while black coffee is known for its stimulating effects due to caffeine and its antioxidants, and green tea is valued for its calming and anti-inflammatory properties, the study found that neither drink had an immediate impact on the body's metabolic processes.

Prof Singh suggested that more research with larger groups and longer study periods is needed to explore any potential long-term effects of black coffee and green tea on metabolism.

"This study adds to the growing understanding of how these popular drinks affect our health," she said.