- New research suggests coffee and green and black tea may help reduce the risk of type 2 diabetes.
- Specifically, the caffeine in those drinks and the effect it can have on body fat and weight, may be the reason for the reduced risk.
- In addition to boosting metabolism, caffeine has a number of other potential health benefits, such as increasing alertness and concentration, enhancing exercise performance, and improving mood.
- However, experts warn that consuming too much caffeine can also have negative effects, such as anxiety, insomnia, and jitteriness
Coffee and green and black tea are bursting with antioxidants, natural compounds that have been linked to a number of health benefits.
But the caffeine present in those beverages may also offer its own benefits, including reducing the risk of type 2 diabetes, suggests a new genetic study. This is possibly due to the effect of caffeine on body fat and weight.
“Our … finding suggests that caffeine might, at least in part, explain the inverse association between coffee consumption and risk of type 2 diabetes,” write the researchers.
The results of the new study fit with other research suggesting a link between caffeine and type 2 diabetes risk.
However, these studies weren’t designed to tease apart the potential effects of caffeine from those of antioxidants.
To overcome this limitation, the authors of the new study used a genetic method called
The cardiovascular outcomes they looked at included coronary artery disease, stroke, heart failure, and irregular heart rhythm (atrial fibrillation).
The new study was published March 14 in BMJ Medicine.
For the Mendelian randomization, researchers focused on two common genetic variants for two genes associated with how quickly the body metabolizes ingested caffeine.
People who carry the genetic variants associated with slower metabolism of caffeine drink less coffee, on average. However, they have higher levels of caffeine in their blood compared to people who metabolize caffeine more quickly.
For this study, the researchers examined genetic and other data from nearly 10,000 people of predominantly European ancestry who were taking part in six long-term studies.
They found that people who were genetically predisposed to have higher levels of caffeine in their blood were more likely to have a lower body mass index (BMI) and body fat.
In addition, they had a lower risk of type 2 diabetes. Researchers estimated that about half of the reduced diabetes risk was due to the lower BMI.
In contrast, no link was seen between genetically predicted caffeine levels in the blood and risk of cardiovascular disease outcomes.
One limitation of the study is that it included data mainly from people of European ancestry, so the results may not apply to other groups.
In addition, researchers looked at only two genetic variants associated with caffeine metabolism. Other variants might also shape a person’s type 2 diabetes risk in relation to their caffeine intake.
The results of the new study support the link between caffeine intake and a lower risk of type 2 diabetes.
But Dr. Denise Pate, an internal medicine physician and medical director with the Medical Offices of Manhattan in New York City, pointed out that researchers did not look specifically at the link between caffeine metabolism and blood glucose levels, which is how type 2 diabetes is diagnosed.
Still, some research suggests possible ways in which caffeine might reduce the risk of type 2 diabetes.
“Caffeine works as a thermogenic, meaning that it increases energy expenditure — you can think of it as micro-exercise,” said Pate.
In addition, “caffeine has the properties of increasing satiety, meaning it suppresses the desire to eat, therefore leading to a lower BMI,” she said.
However, it’s not clear if “prescribing” caffeine would help prevent people from developing diabetes.
The authors of the new study called for “randomized controlled trials … to assess whether non-caloric caffeine-containing beverages might play a role in reducing the risk of obesity and type 2 diabetes.”
“As of now, I would not recommend people start drinking caffeine as a method to reduce their diabetic risk,” said Pate.
Instead, she recommends that people focus on regular physical activity and healthy eating, both of which are known to
In addition to boosting metabolism, caffeine has a number of other
“Consuming too much caffeine can have negative effects, such as anxiety, insomnia and jitteriness,” she said.
Most healthy adults can consume up to 400 milligrams of caffeine per day, according to the
This amount is roughly
People should “avoid consuming [caffeine] in forms that are high in added sugars and fats,” said Rydyger, “as these can contribute to negative health effects such as weight gain and tooth decay.”
This includes limiting how much milk and sugar you add to your coffee or tea, and limiting your consumption of sugar-sweetened sodas, energy drinks or other beverages.
This advice is especially important for people who already have type 2 diabetes, or for those at risk of developing it.
In addition, “it’s important to be mindful of the time of day when consuming caffeine, as it can interfere with sleep quality if consumed too late in the day,” said Rydyger. “A good rule of thumb is avoiding any forms of caffeine after 12 p.m.”