It is suggested that caffeine contained in coffee and tea may reduce the risk of obesity and diabetes

Caffeine contained in coffee, green tea, energy drinks, etc. has a wakeful effect by stimulating the central nervous system, and when ingested, it reduces drowsiness and fatigue, but excessive intake may cause diarrhea and nausea. . A paper by a team at the Karolinska Institutet in Sweden suggests that high blood caffeine levels may lower body fat percentage and reduce the risk of type 2 diabetes.

Appraisal of the causal effect of plasma caffeine on adiposity, type 2 diabetes, and cardiovascular disease: two sample mendelian randomisation study | BMJ Medicine
http://dx.doi.org/10.1136/bmjmed-2022-000335

Caffeine may reduce body fat and risk of type 2 diabetes, study suggests | Medical research | The Guardian
https://www.theguardian.com/science/2023/mar/14/caffeine-may-reduce-body-fat-and-risk-of-type-2-diabetes-study-suggests

Based on previous studies, the research team thought that drinking 3 to 5 cups of coffee containing an average of 70 to 150 mg of caffeine every day may be associated with a reduced risk of type 2 diabetes and cardiovascular disease. Because the referenced paper was an observational study , it was difficult to determine whether caffeine or other compounds were responsible for the reduced risk of cardiovascular disease associated with type 2 diabetes and obesity, the research team said. .

The research team used a method called `` Mendelian randomization '' to clarify the causal relationship by genetic evidence, and discovered two common gene variants related to the rate of caffeine metabolism. We have found that moderate caffeine levels are associated with lower BMI and body fat.

People who are genetically slow metabolizers of caffeine have higher blood levels of caffeine than those who metabolize caffeine faster, even though they drink less coffee on average. Caffeine is known to increase metabolism, promote fat burning, and reduce appetite, and is estimated to increase daily energy expenditure by approximately 100 kcal at a dose of 100 mg per day. Therefore, high blood caffeine levels increase energy expenditure, lead to weight loss, and as a result reduce the risk of type 2 diabetes and cardiovascular disease.

The research team commented on the relationship between blood caffeine levels and type 2 diabetes risk, ``Further research is needed, but drinking calorie-free caffeinated beverages to reduce obesity and type 2 diabetes is effective. It is also possible,” he said.

Associate Professor Stephen Lawrence of the University of Warwick School of Medicine says that the results of this study may lead to research to develop promising treatments in the future, but on the other hand, evaluation by Mendelian randomization It is a relatively new method, and although it is useful, it is weak against bias.

Lawrence also said that increasing blood caffeine levels is less effective in reducing the risk of type 2 diabetes and cardiovascular disease than reducing calorie intake and increasing physical activity. In addition, caffeine intake may cause palpitations and heart rate abnormalities in some people, so it is not suitable for everyone.

“Should people drink more coffee to reduce their risk of obesity and type 2 diabetes? Scientifically, there is relatively reliable evidence that caffeine promotes fat burning even at rest.” However, caffeine consumption is not necessarily a cure for obesity and can lead to weight gain and harm if used incorrectly,' said Associate Professor Lawrence.