Coffee and health is a powerful stuff. Researchers discovered earlier this year that just a whiff is enough to increase the body’s arousal levels, helping peoples wake up and feel focused.
Yet purported links to cancer, poor heart health, and shorter lives have percolated for decades. Now, better-brewed studies are debunking the previous bad news and linking coffee even several cups a day to specific health benefits and longer life.
One study revealed that, contrary to prior research, drinking coffee isn’t thought to stiffen the arteries, which can force the heart to work harder and lead to a heart attack or stroke. Researchers pored through a database of 8,412 people who had MRI heart scans and other cardiovascular tests and who answered questions about their coffee consumption.
They found there was no difference in the stiffening of arteries among the people who said they had less than a cup a day versus those who drank one to three, or even four to five cups.
Looking at the latest research, coffee seems to be somewhere between relatively benign and beneficial for most healthy adults. A separate study published in the journal JAMA Internal Medicine last year, which relied on the same dataset used by Fung’s team, “suggests a lower risk of death was associated with drinking more coffee, including among coffee drinkers who have eight or more cups per day.”
A 2017 review of 201 coffee studies and 17 clinical trials, published in The BMJ, found coffee was “associated with a lower risk of several cancers, including prostate, endometrial, skin and liver cancer, as well as type 2 diabetes, gallstones, and gout.” Above that, the researchers discovered positive effects on brain health: Coffee consumption was linked to a lower risk of Parkinson’s disease, depression, and Alzheimer’s disease.
Looking at the latest research, coffee seems to be somewhere between relatively benign and beneficial for most healthy adults. So why has it gone from pure vice to potential virtue?
It’s the study design: Most older studies linking coffee directly to heart disease, a variety of cancers, and overall increased risk of death didn’t account for other factors, such as that coffee drinkers might be more likely to smoke or drink excessively, according to the Mayo Clinic. Many studies simply had weak methodology, says Dr. Robert Shmerling, a practicing physician and editor at Harvard Health Publishing.
In 2016, the World Health Organization removed coffee from its list of potentially carcinogenic foods, based on the evidence for coffee’s benefits, and lack of evidence for serious risks. That’s convenient, since nearly two-thirds of Americans drink it daily, according to the National Coffee Association.
Researchers are still figuring out where coffee’s health benefits come from. But, surprisingly, they’ve ruled out a connection to caffeine. A double-shot of research, reported in a 2017 issue of Annals of Internal Medicine, linked coffee to longer life and reduced risk of death from all causes.
One of the studies, billed as the largest of its kind, looked at coffee consumption and mortality among 521,330 people across Europe. The other 2017 study made a similar analysis of more than 215,000 people, but expanded the heretofore limited ethnic breadth of coffee research: “Drinking coffee was associated with a lower risk of death due to heart disease, cancer, stroke, diabetes, and respiratory and kidney disease for African-Americans, Japanese-Americans, Latinos and whites.”
This study is the largest of its kind and includes minorities who have very different lifestyles. Seeing a similar pattern across different populations gives stronger biological backing to the argument that coffee is good for you whether you are white, African-American, Latino or Asian.
Coffee contains a lot of antioxidants and phenolic compounds that play an important role in cancer prevention. Although this study does not show causation or point to what chemicals in coffee may have this ‘elixir effect,’ it is clear that coffee can be incorporated into a healthy diet and lifestyle.
Antioxidants and other compounds in coffee have, in fact, been linked to reduced inflammation, as free radicals in the body are tamed, possibly lowering the risk of many illnesses. However, specific research on these mechanisms and thus why coffee appears to be beneficial, remains elusive.
There are conflicting views on whether caffeine is truly addictive, but stopping a heavy coffee habit can bring on headaches. Caffeine, especially when consumed in the evening, can also impair sleep, and poor sleep is associated with increased risk of heart disease, depression, and other ills.
Coffee does not stunt growth, but given its strong stimulant effects, experts agree it’s bad for kids. Pregnant women are advised to cut out coffee because it can cause low birth weight. There are also hints that too much coffee might contribute to osteoporosis in women, but the link is not conclusive.
Research suggests that coffee does raise blood pressure in people not used to it, but not in habitual coffee drinkers. Oh, and coffee does not stunt growth, but given its strong stimulant effects, experts agree it’s bad for kids. Researchers don’t suggest coffee lovers up their consumption, or that non-coffee-drinkers should start up. And exactly zero scientists recommend 25 cups a day.
When consumed in moderation, coffee can be very good for your brain. However, when consumed late in the day, it may reduce the quality of your sleep and subsequently make you feel more tired.
Moderation is key. When consumed in excess, caffeine can cause anxiety, jitters, heart palpitations and sleep problems. While millions of people can drink many cups of coffee per day, many people are sensitive to caffeine. For people who tolerate it, coffee can provide many impressive benefits for the brain.
To reserve the health benefits, drink your coffee without sugar. If it tends to affect your sleep, don’t drink it after 2pm. It pays to be mindful of what you’re putting in your coffee and how many cups you’re consuming a day. That being said, children, adolescents, and pregnant women need to limit their caffeine intake.
The mounting evidence of caffeine consumption as a potentially protective factor against cognitive impairment is exciting. Until we have a clear and huge scientific answer, enjoy your coffee in moderation. And remember, take note of your caffeine tolerance. If you start to feel nervous or jittery, or experience headaches, it’s probably time to reduce your intake or switch to decaf.