STOCKHOLM, Sweden — Three cups of coffee a day could curb obesity and prevent diabetes, a new study explains. Scientists in Sweden believe calorie-free caffeinated drinks should be a major target of investigation when it comes to tackling weight gain and the onset of Type 2 diabetes.
The new study shows the greatest benefit appears among those with a genetic predisposition to metabolize caffeine much slower than others, leaving more of the substance in their blood. Prior research has linked drinking three to five cups of coffee a day with lower risks of Type 2 diabetes and cardiovascular disease.
Scientists already know that the stimulant boosts metabolism, increases fat burning, and reduces appetite. Consuming 100 mg a day (around one cup of coffee) increases energy expenditure by an estimated 100 calories daily.
In the latest development, the Karolinska Intitutet team found that people who metabolize caffeine slowly — due to certain genes — increased the amount of caffeine in the blood. This increased the fat-burning impact of the stimulant, and reduced their risk of Type 2 diabetes.
Which genes dictate how you metabolize caffeine?
To reach their conclusions, the team reviewed earlier studies to reveal caffeine’s effect on body fat and Type 2 diabetes onset. They also investigated how the link between caffeine and the body changes with people’s genetic makeup.
Scientists focused on two common genetic variants that dictate how fast caffeine metabolizes in the body — CYP1A2 and AHR. Results show participants consumed less caffeine when they had a genetic predisposition to metabolize the stimulant slowly. Despite that, the same people have more of the substance in their blood than those who metabolize it quickly.
High blood caffeine levels displayed a link with lower weight, body fat, and risk of Type 2 diabetes onset — provided they were among the group with the genes dictating slower caffeine consumption and had higher caffeine blood level scores.
Further results revealed weight loss drove 43 percent of caffeine’s effect on Type 2 diabetes risk.
“Our mendelian randomization finding suggests that caffeine might, at least in part, explain the inverse association between coffee consumption and risk of Type 2 diabetes,” the researchers write in the journal BMJ Medicine.
“Randomized controlled trials are warranted to assess whether non-caloric caffeine containing beverages might play a role in reducing the risk of obesity and type 2 diabetes.”
The team also studied the effect on cardiovascular disease risk, but they did not discover a strong link to genetically-predicted blood caffeine levels. The team studied 10,000 people, predominantly of European descent, all of whom were already taking part in six long-term studies.
South West News Service writer Pol Allingham contributed to this report.