Researchers investigated the effects of a genetic predisposition to high caffeine levels on measures of body fat, type 2 diabetes risk, and cardiovascular risk.
As the most consumed psychoactive substance globally, caffeine is commonly found in coffee, tea, and soft drinks.
Research has suggested that consuming caffeine is associated with weight loss, reduced body mass index (BMI), and fat mass. Consequently, this may lower the risk of conditions linked to overweight or obesity, such as type 2 diabetes and cardiovascular disease.
Although it is unclear how much of these benefits are directly attributed to caffeine, a study revealed a 7% decrease in type 2 diabetes risk per additional cup of caffeinated coffee consumed per day, and 6% per cup of decaffeinated coffee.
Obtaining further insight into how caffeine consumption influences the development of cardiometabolic conditions could aid in developing dietary strategies that reduce the risk of these conditions.
In a recent study, researchers explored the effect of a genetic predisposition to higher caffeine levels in the bloodstream. Their findings suggest that those with a genetic predisposition to higher caffeine levels in the blood have a lower risk for type 2 diabetes.
Slower caffeine metabolism
The study analyzed genome-wide association data from 9,876 individuals, mostly of European ancestry. The researchers focused on two common genetic variants – CYP1A2 and AHR genes, which slow down caffeine metabolism. Individuals carrying these variants require less coffee to have elevated caffeine levels in their blood than those who metabolize caffeine quickly.
The researchers collected data on body fat, type 2 diabetes risk, and risk for cardiovascular conditions. After analyzing the data, the researchers found that genetically predicted higher blood levels of caffeine were associated with lower BMI, whole body fat mass, and type 2 diabetes risk.
Further analysis revealed that 43% of the protective effect of blood caffeine levels on type 2 diabetes was due to weight loss. However, no strong link was found between genetically predicted caffeine levels and cardiovascular conditions such as ischemic heart disease, heart failure, and stroke.
Caffeine and weight loss
Dr. Dana Ellis Hunnes, an assistant professor at UCLA Fielding School of Public Health who was not involved in the study, explains that higher caffeine intake can increase thermogenesis, or heat production, in the body, leading to calorie burn. As a result, this increase in calorie burn can help with weight loss and fat loss.
Dr. Rohini Manaktala, a cardiologist at Memorial Hermann in Houston, TX who was also not involved in the study, suggests that caffeine accelerates weight loss by speeding up metabolism. She explains that this is a dose-dependent process, meaning that an increase in caffeine intake leads to more calorie and fat burning, resulting in weight loss. Additionally, caffeine suppresses an individual’s appetite, inhibiting overindulgence in eating, which can further prevent weight gain.
Regarding caffeine’s effect on type 2 diabetes risk, Dr. Mark Guido, an endocrinologist with Novant Health Forsyth Endocrine Consultants in Winston Salem, NC who was not involved in the study, indicates that the science is inconclusive. However, he suggests that caffeine may impact how the body uses glucose and insulin, which may reduce the risk of type 2 diabetes.
In conclusion, the researchers found that higher levels of caffeine in the bloodstream might result in weight loss and lower the risk of developing type 2 diabetes.
Limitations
Dr. Guido acknowledged that the study has significant limitations. He stated that it focused on individuals with naturally elevated caffeine levels and a certain genetic predisposition and did not examine elevated caffeine levels from food or drink. Therefore, it is uncertain whether these findings would apply to increased caffeine levels from food or drink.
Additionally, Dr. Guido noted that the study only focused on reducing the risk of developing type 2 diabetes and not on how caffeine affects those already diagnosed with the condition.
Dr. Hunnes cautioned that the results are not truly causal, unlike randomized controlled clinical trials that study the entire person. The study only investigated the effects of genomes, similar to observing test tube issues and making assumptions about how they will react in a person.
Dr. Manaktala recommended conducting a more comprehensive randomized controlled study to examine the real clinical and health effects of caffeine. Moreover, the study participants were of European descent, making it challenging to generalize the study findings to the broader U.S. population.
Implications
According to Dr. Manaktala, the study’s findings are “exciting” because they suggest that a “healthy dose” of caffeine may help prevent obesity, a major risk factor for cardiovascular conditions. However, she advises caution before completely accepting the study’s findings and adopting new dietary habits. She emphasizes that caffeine cannot be a substitute for a healthy lifestyle, which includes eating plenty of fruits, vegetables, lean meats, and a moderate intake of carbohydrates/fats, along with daily moderate-intensity physical exercise and careful management of chronic conditions that are risk factors for heart disease.
Dr. Guido acknowledges the interesting nature of the study but states that he would not make any different recommendations to his patients based on its findings. He believes that further studies are likely needed before any changes are made to recommendations for the prevention of type 2 diabetes. He advises against altering caffeine intake based solely on this study, as it only looked at people with naturally high caffeine levels and did not consider caffeine intake from food or drink.
Dr. Guido also notes that too much caffeine can have significant harmful effects on health, such as elevated blood pressure and poor sleep. For patients who already have type 2 diabetes, caffeine can make their sugars worse. Therefore, caution is warranted when considering caffeine intake as a preventive measure against obesity or diabetes. A healthy lifestyle that includes a balanced diet and regular physical activity remains the most effective strategy for preventing these conditions.
