The scientists performed a multi-pronged study to reach that conclusion. First, they analysed blood from people in their 20s and those over 60. They found that that the older participants had higher activity of gene associated with the production of a certain circulating inflammatory protein, called IL-1-beta.
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Then, they examined the blood from the older participants more closely. The researchers discovered that people with higher activation of those genes reported drinking less caffeine than those in the lower-activation group. They were also more likely to have high blood pressure, stiff arteries—a heart disease risk factor—and higher concentrations of IL-1-beta in the blood.
The scientists wanted to see if that protein was responsible for the heart-unhealthy effects. So they injected mice with substances that boosted the production of IL-1-beta. This triggered massive systemic inflammation and high blood pressure in the rodents.
Then, the scientists took another look at the blood from the older participants. They verified that the lower-activation group’s blood did contain more caffeine and its associated byproducts than those in the higher-activation group.
So the scientists performed one more experiment: They added inflammation-causing compounds to human immune cells in the lab, and then added caffeine into the mix, too. They discovered that caffeine prevented those compounds from producing their inflammatory effects.
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This shows that the underlying inflammatory process might be triggered by something scientists may be able to target and combat, the researchers say. That can potentially help how we prevent and treat heart disease and certain cancers.
More research needs to be done, but in the meantime, science seems to support your refill: In fact, the more coffee people drank, the more protected against inflammation they seemed to be, TIME reports.
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