Why Do Coffee Drinkers Live Longer? Scientists Think They’ve Found One Reason

Why Do Coffee Drinkers Live Longer? Stanford Scientists Think They’ve Found One Reason Why

It’s pretty well established science by now that coffee drinkers live longer. Study after study has uncovered correlations between drinking coffee and lowered risk of various age-related diseases. Most of the earlier studies focused on specific diseases. There’s fairly convincing evidence that coffee helps prevent diabetes, cardiovascular disease, various cancers, Alzheimer’s disease and a host of diseases that are suspected to have something to do with a malfunctioning immune system. Then a few years back, one coffee study led to one of our favorite coffee-related headlines of all time:

Needless to say, the headline was just a bit of hyperbole. What the study actually found was that people who drank at least six cups of coffee a day were less likely to die of any cause during the study’s 14-year-long duration. The study’s authors were quick to point out that – in scientific lingo – correlation does not equal causation. Scientists found a link between coffee and longevity, but that didn’t mean that coffee was the reason coffee drinkers in the study lived longer. That was back in 2012, and in the years since, many teams of researchers have delved deeper into trying to figure out why coffee drinkers seem to live longer than those who avoid drinking coffee and caffeinated beverages. A 2015 study found that coffee drinkers were less likely to die from cardiovascular diseases, neurological diseases, suicide, and a very recent study found a link between coffee and a reduction in plaques found in the brains of people with Alzheimer’s disease.

Coffee Drinkers Less Likely to Develop Inflammation-Related Diseases

This latest Stanford study on coffee and longevity focused on diseases linked to chronic, age-related inflammation. According to the study’s lead author, David Furman, PhD, more than 90% of non-communicable age-related diseases are linked to chronic inflammation. Those diseases and conditions include cardiovascular diseases, Alzheimer’s disease and other dementias, osteoarthritis and depression. Co-author Mark Davis, PhD, noted that the study shows that cardiovascular diseases are driven by an underlying chronic inflammation and that the inflammation is driven by “molecular events” on the cellular level.

In layman’s terms, something activates an inflammatory response in the bodies of some people, but not others. Furman’s researchers analyzed blood drawn from participants in a long-term study started 10 years ago to examine the immunology of aging. They started by comparing the blood of younger study participants with those of participants over the age of 60. The analysis pinpointed two specific gene clusters that are more active in older adults than they are in those between 20 and 30 years old. Those genes produce an inflammatory protein, IL-1-beta.

In addition, the researchers were able to divide the older adults into two groups based on how active those two gene clusters were. When they reviewed the medical histories of both groups, they found that those with high activation of those gene clusters were more likely to have high blood pressure and other risk factors for cardiovascular disease and complications. When they analyzed blood drawn from each group, they found that those with high activation had higher levels of IL-1-beta, as well as substances that result from the breakdown of nucleic acid by free radicals.

Through a series of experiments, Furman and the research team determined that immune cells incubated with those substances triggered massive inflammation in mice injected with them. When the scientists added caffeine to the mix before injecting the immune cells into the mice, there was much less inflammation.

Davis noted that the study doesn’t show a causal link between coffee and longevity.

“We didn’t give some of the mice coffee and the others decaf. What we’ve shown is a correlation between caffeine consumption and longevity,” he said. “And we’ve shown more rigorously, in laboratory tests, a very plausible mechanism for why this might be so.”