Scientific Study: Drinking Coffee Prolongs Life, Even If You Drink More of It

Coffee is a magical thing. Earlier this year, researchers discovered that a little bit of coffee's aroma is enough to increase the body's level of alertness and make people feel awake and focused. Coffee has long been linked to cancer, impaired heart health, and a shorter lifespan. Now, new research is debunking previous claims and proving it: even drinking tons of coffee every day can lead to a healthier and longer life.

Unlike previous studies, a new investigation has found that drinking coffee does not cause atherosclerosis, which causes the heart to work harder, further triggering a heart attack or stroke.

The researchers scrutinized a database that included 8,412 samples of people who underwent heart MRI scans and other cardiovascular tests and provided their respective coffee intake. They found that there was little difference between those who consumed almost no coffee and those who consumed one to three, or even four or five cups a day, in terms of suffering from atherosclerosis. There were also some people who claimed to drink 25 cups of coffee a day, but these were excluded from the survey.

"Although we weren't able to prove a causal link in this study, we have at least demonstrated that the effect of coffee on arteries is not as bad as previous studies have made it out to be," said Kenneth Fung of Queen Mary University of London, a member of the research team. However, he warned, "These coffee intakes were provided by the researchers themselves, so there are limitations and the true intake may be over- or underestimated." The study has been presented at a meeting of the British Cardiovascular Society on June 3rd.

According to the latest research, coffee seems to be beneficial to most healthy adults.

Another study published last year in JAMA Internal Medicine, using the same database as Fung's experiment, demonstrated that "people who consumed more coffee had a lower risk of death, instantly consuming more than eight cups of coffee per day."

A 2017 review published in the British Medical Journal covering 201 studies and 17 clinical trials on coffee found that coffee can "reduce the risk of certain cancers, including prostate, endometrial, skin and liver cancer, as well as type 2 diabetes, gallstones and gout." In addition to this, researchers have found that coffee also has a positive effect on brain health: it reduces the chances of developing Parkinson's, depression and Alzheimer's disease.

According to the latest research, coffee appears to be beneficial to most healthy adults. So why has drinking coffee gone from being a pure vice to having potential value?

It's because the studies were designed differently: the Mayo Clinic points out that most of the early studies directly linked coffee to heart disease, cancer, and some factors that increase the risk of death, but didn't take into account other factors, such as the possibility that coffee drinkers might smoke or drink heavily. Dr. Robert Shmerling, a practicing physician and editor at Harvard Health Press, said many studies just used simple methods.

Because of the evidence that has been shown to be beneficial and the lack of evidence of health risks associated with coffee, in 2016 the World Health Organization removed coffee from its list of potentially carcinogenic foods. This came as a relief to many, as data from the American Coffee Association shows that two-thirds of Americans drink coffee every day.

Researchers are still exploring where coffee's benefits to human health come from, but they've ruled out a caffeine connection.A dual study published in the Annals of Internal Medicine in 2017 suggests that regular coffee consumption (with or without caffeine) can extend life and reduce the risk of death from all causes.

One of the studies, considered the largest of its kind, investigated coffee intake and mortality among 521,330 Europeans and came to the following conclusions:

"The more coffee you drink, the lower your risk of death, and the risk of dying from circulatory and digestive diseases is especially reduced," said Marc Gunter, first author of the study and a nutrition expert at the International Agency for Research on Cancer, "Drinking more coffee also helps improve liver function and the immune response. Importantly, the findings were similar across the 10 European countries, even though their coffee-drinking habits and lifestyles varied."

Another 2017 study did a similar analysis of 215,000 individuals, but expanded the restrictions on ethnicity: "The reduced risk of death from drinking coffee is due to the reduced risk of heart disease, cancer, stroke, diabetes, respiratory and kidney disease for African Americans, Japanese Americans, Latinos and whites."

"This study is one of the largest of its kind, and included ethnic minorities with very different lifestyles," said Veronica Setiawan, associate professor of preventive medicine at the Keck School of Medicine of the University of Southern California and lead author of the study, "whether white, African Americans, Latinos or Asians, similar patterns were found in these diverse populations, providing a stronger biological basis for the claim that coffee is good for health."

Setiawan drinks one or two cups of coffee a day, and she hypothesizes that coffee is beneficial for a reason:

"Coffee is high in antioxidants and phenolic compounds, which have an important role in cancer prevention," she said. "Although this study failed to prove the 'life-extending' effects of the chemicals in coffee, it is clear that coffee can be incorporated into a healthy diet and lifestyle."

In fact, antioxidants and other compounds contained in coffee have been linked to a reduction in inflammation, as free radicals in the body are suppressed, reducing the likelihood of a number of diseases. However, very little specific research has been done on these mechanisms.

Coffee is not without health risks. It contains more than 1,000 chemicals, most of which have not yet been studied. Graham Davey, a professor of psychology at the University of Sussex, says caffeine is a powerful stimulant that can cause "nervousness, irritability, trembling, palpitations, flushing and an irregular heartbeat" in some people. But while opinions vary on whether caffeine is actually addictive, abruptly stopping a coffee habit can lead to headaches.

Caffeine, especially when ingested at night, reduces the quality of sleep, and poor sleep increases the risk of heart disease, depression, and other illnesses.

Coffee does not stunt children's growth, but given its strong stimulating effects, experts agree that it is harmful to children.

Women who are pregnant should try not to drink coffee as it can lead to low birth weight. There are also indications that too much coffee can cause osteoporosis in women, but this claim has not been proven.

Studies have shown that people who are not used to coffee do experience an increase in blood pressure because of it, while those who are used to drinking it do not. Also, coffee does not stunt children's growth, but given its strong stimulating effects, experts agree that it is harmful to children.

For otherwise healthy adults, the U.S. government's Healthy Eating Guidelines recommend that "moderate amounts of coffee (three to five 8-ounce cups or coffee containing 400 mg of caffeine) can be included in a healthy diet."

The 8-ounce recommendation is outdated, and researchers aren't recommending that coffee lovers drink more, or that non-coffee drinkers start. And no scientist recommends drinking as many as 25 cups a day.