Worldwide, an estimated 2.25 billion cups of coffee are consumed every day.
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COFFEE—A CUP OF HEALTH
Americans love coffee. We drink about 400 million cups of coffee a day, making us the leading coffee-consuming nation in the world. An estimated 83 percent of American adults drink coffee. The average cup of coffee is nine ounces, and we drink about three cups every day. American coffee drinkers spend an average of $1,100 a year on coffee. Coffee is considered the ultimate energy drink. Most people drink it in the morning to get them going and in the afternoon to give them the necessary pick-up-up-up-up. “In Seattle,” according to Amazon founder and CEO Jeff Bezos, “you haven’t had enough coffee until you can thread a sewing machine while it’s running.”
Americans also drink it because we love its taste: about a third of all the coffee we buy is considered gourmet coffee, meaning it is espresso-based or otherwise a specialty drink.
We’re not the only people who love coffee. Worldwide, an estimated 2.25 billion cups of coffee are consumed every day. Mostly we drink coffee because we love its taste and because it provides an instant energy boost. Former late-night host David Lettermen once admitted, “If it wasn’t for coffee, I’d have no identifiable personality whatsoever.”
With the meteoric rise of Starbucks and America’s estimated 25,000 other coffee shops, the availability of various special preparations and blends of coffee, and the ease of one-cup coffeemakers, the once-bland world of coffee has been transformed into one of the fastest-growing food and beverage industries in the county. Business has discovered that coffee is indeed the multi-billion-dollar bean. Few people look forward to their daily stop at the local coffee shop more than I do. In addition to getting my coffee, I’m going to meet friends there, and we’ll sit together for a few minutes enjoying our coffee and the joy of companionship.
But few people drink it for the most important reason: Coffee is really good for you. I make that statement as a physician and liver specialist. In fact, coffee actually may well be the healthiest beverage you can drink. Many people don’t believe that. When I make that statement they sometimes look at me like I’ve told the beginning of a joke and they are waiting for the punch line. Often when I’m giving a lecture on a liver disorder, I will ask everyone in the audience who drinks at least two cups of coffee to raise their hands. Most hands, both of men and women, go up. “Good,” I tell them, then ask, “How many of you drink at least four cups a day?” Fewer hands are raised, and I notice that people look around the room nervously to see who is drinking that much coffee. Finally I ask my audience, “How many of you average six or more cups of coffee a day?” In response there is always some sort of nervous laughter and then a few brave people gingerly raise their hands, as though they were doing something wrong. That’s when I say to the audience, “You know what? It’s good for you! You’re really doing yourself a big favor.”
In fact, instead of believing coffee is good for you, most people believe it can be harmful. In the past drinking too much coffee supposedly had been linked to a variety of health problems including heart attacks, birth defects, pancreatic cancer, osteoporosis, weight gain, hypertension, and miscarriage. We do know that in some instances coffee can cause insomnia, tremors, raise blood pressure a tad, and worsen heartburn, and it certainly increases urination. For those reasons people usually limit the amount of coffee they drink and often decide that for health reasons they shouldn’t have that extra cup of coffee they are craving. I often hear this common refrain: “Dr. Chopra, I used to drink two cups of coffee a day. Now I hardly drink it. Isn’t caffeine bad for you?”
The evidence that they are misinformed is overwhelming, and more of it is being reported practically every day. While many people read those stories, they still don’t believe them. Few people consider coffee a health drink. In fact, most people don’t even know how effective coffee appears to be in preventing a variety of very serious illnesses, or, when they learn the facts, they remain quite dubious. They ask incredulously, “You’re saying coffee is probably better for me than tea? Coffee really can reduce the risk of developing a number of common cancers? It can decrease the risk of developing gallstones and tooth decay? It decreases the risk of developing cirrhosis of the liver? It can even decrease the risk of developing dementia? Dr. Chopra, are you nuts?”
I have become a true advocate of the health benefits of coffee, so much so that many of my medical colleagues are amused by my passion for coffee. For years I spent four weeks attending on the in-patient hepatology service at Beth Israel Deaconess Medical Center, a major teaching affiliate of Harvard Medical School. To satisfy my own curiosity I instructed the students, interns, residents, and fellows to ask all the patients admitted with severe liver disease one additional question: How much coffee do you drink? The answer I always got was that none of our patients with severe liver disease regularly drank coffee. It’s quite uncanny and quite remarkable how consistent this answer had been, week after week, for years. But a couple of years ago, as I was about to start teaching rounds, a resident approached me smiling broadly and said, “Dr. Chopra, we finally have a patient on our liver service who drinks four cups of coffee every day!”
Oh, well, that caught my attention. I said, “Tell me more about him.”
The resident responded, “He’s a fifty-three-year-old patient who was admitted yesterday with severe cellulitis.”
I told the house staff, “When we go and see him at rounds, I will take my own history. He may well be the exception to the rule. The studies are epidemiological and may not be iron-clad, even though there are some reasonable mechanistic explanations.”
When I met this patient I took a detailed history. In addition to the questions about alcohol and over-the-counter medications, I said to him, “Please tell me about tea and coffee. Do you drink any?”
“I don’t drink tea at all,” he said, shaking his head. “But I love coffee.”
I asked him if he drank regular or decaf, since most studies had shown that it is regular coffee that confers major protection against liver disease.
“Only regular,” he said, smiling, “If you’re going to drink coffee you might as well drink the real thing.”
I asked him how many cups of coffee he drank every day.
“At least four,” he said, “sometimes more.”
“What size?” I inquired.
He pointed to a large paper cup on his bedside table and said, “That size.”
I asked one final question, “How long have you been drinking regular coffee?”
And matter-of-factly he responded, “Ever since my liver transplant.” He then turned to me and asked, “Should I stop? Is it bad for me?”
“No, it’s not,” I said, repressing a laugh. “Keep drinking it, it’s very good for you.
No wonder coffee hadn’t prevented his disease. I asked him, “Did someone tell you to drink coffee after your transplant?”
He shook his head again. “It’s really strange. I never used to like coffee, but after my transplant I suddenly had this incredible craving for coffee!” The facts are indisputable; coffee appears to offer a great variety of benefits, including substantial protection against liver cirrhosis, type 2 diabetes, heart disease, Parkinson’s disease, cognitive decline and dementia, gallstones, tooth decay, and a host of common cancers, including prostate, colon, endometrial, and skin cancer. There also is a lower rate of suicide among coffee drinkers.
Incredible as it may seem, coffee also appears to make you smarter, can improve physical performance—major league baseball players may drink as many as six cups of coffee during a game to increase focus and response time—and even helps burn fat. It can be used to treat headaches, and, contrary to conventional wisdom, it appears to lower the risk of being hospitalized for arrhythmia.
But perhaps the single most startling conclusion that has emerged from the more than 19,000 studies concerning the impact of coffee on health is that people who drink a lot of coffee appear to live longer than people who drink little or no coffee. That’s an incredible statement, but there are several good studies that support it. A National Institutes of Health study published in the New England Journal of Medicine in 2012 analyzed data collected from 400,000 participants over a fourteen-year period and concluded that the overall mortality rate for people who drank between two and six cups of coffee a day was about 10 percent lower for men and about 15 percent lower for women. The study found that the more coffee participants drank, the more they cut their risk of death, with the greatest benefit seen in people who enjoyed four or five cups. Interestingly, women benefitted slightly more than men.
Coffee drinkers have a lower risk of developing cirrhosis, cancer of the liver, and type 2 diabetes.
A Johns Hopkins Bloomberg School of Public Health review of twenty-one studies conducted between 1966 and 2013 that included almost a million participants concluded that people who drank as many as four cups of coffee daily reduced mortality by 16 percent.
There is one caveat though: Studies also show that coffee consumption often is linked with known health risks (e.g., coffee drinkers tend to smoke), which tends to skew the results.
Considering the myriad of potential health benefits to be gained from drinking coffee, it is somewhat surprising how little most Americans know about them. I am also surprised that an overwhelming number of physicians are not aware of the many benefits of coffee. If a patient says to his primary care physician, “I heard coffee has lots of health benefits,” the response they often hear is, “These studies come and go. Everything in moderation is okay.” In reality, this is inaccurate. Scores and scores of well-conducted studies have been published in prestigious, peer-reviewed medical journals. There appears to be a dose-dependent effect—in other words, the more coffee an individual consumes on a daily basis, the greater the benefit or the risk reduction in many of the common medical ailments mentioned above.
Coffee drinkers, both men and women, have lower total and cause-specific mortality compared to those who do not drink coffee.
While many people can rhapsodize for hours about the nuances of wines, the craft of creating beers, and the history and variations of teas, few people know much about coffee beyond how they order it each morning. But coffee has a rich and bold history and has helped shaped the world as much as any other substance.
Coffee does grow on trees. It is a very hearty plant that can grow in a great variety of conditions, which is why it is such an important economic crop. It is grown around the world. It takes three or four years for a coffee tree to bear fruit. That fruit, the coffee cherry, actually is a bright, deep red color. Rather than a bean, it is a seed, and if it is planted rather than processed it will grow into a tree. Most often these cherries are picked by hand, and in most countries there is a single annual harvest. It takes about two thousand cherries to produce one pound of roasted coffee. After the coffee is dried it is prepared for export, which can be done several different ways. An estimated seven million tons of this “green coffee,” as it is now called, are shipped each year. This green coffee is finally roasted at about 550° into the aromatic brown beans that most of us recognize as coffee, then sold to the consumer while still fresh.
The legend is that the virtues of coffee were first discovered in the ninth century by a shepherd named Kaldi, who observed while tending his goats in the Ethiopian highlands that his flock became unusually active after eating the red berries from certain trees. Supposedly he told the abbot of the local monastery about this curious discovery. According to this story the abbot frowned upon this magical power and angrily threw the berries into the fire. The enticing aroma that arose from the burning beans attracted other residents of the monastery. These roasted beans were brewed into a drink and the monks discovered that it kept them awake and alert throughout the long hours of evening prayer. They shared this knowledge with other monks, and slowly stories about the powers of these red berries to create a vibrant consciousness began spreading throughout the world.
Other legends attribute the discovery of coffee to a Yeminite Sufi mystic who noticed, during his travels through Ethopia, that birds feasting on these red berries seemed more energetic, and when he chewed the berry he enjoyed a similar response. While the truth will never be known, it is generally accepted that the properties of the coffee bean were discovered in Ethopia and exported to Yemen. For hundreds of years coffee remained popular throughout the Islamic world. By the sixteenth century it had spread throughout the Middle East. The word “coffee,” in fact, can be traced to the Arabic qahwa, a slang term meaning “wine of the bean.” Turks translated that to be kahve, which the Dutch called koffie and which entered the English language as “coffee” in 1582.
In many places this qahwa was greeted with suspicion. What kind of strange brew causes such disruptions of the spirit? In 1511 imams in Mecca banned its use, but that ban was overturned a decade later by the Ottoman Turkish sultan. In 1532 it was outlawed in Cairo, and coffee storehouses were reduced to rubble. As it turned out though, it wasn’t only Muslim clerics who tried to prevent the spread of this powerful and seemingly dangerous stimulant.
It was the globe-traveling merchants of Venice who introduced coffee to Europe, where it became known as “the Muslim drink.” It created quite a … stir. The possible medicinal attributes of coffee were first noted in 1583, when German physician Leonhard Rauwolf, after returning from an exploration of the Near East, described “[a] beverage as black as ink, useful against numerous illnesses, particularly those of the stomach.… It is composed of water and the fruit from a bush called bunnu.” Almost instantly there was a debate within the Catholic Church as to whether it would be permitted or banned; there is considerable dispute as to precisely which church leader eventually made the decision. Some credit Pope Clement VIII, while others believe it was Pope Vincent III, but the story goes that the pope demanded to taste it before rendering his decision and that, after doing so, rather than banning it he proclaimed, “Why, this Satan’s drink is so delicious that it would be a pity to let the infidels have exclusive use of it. We shall cheat Satan by baptizing it.”
At that time nations often tried to control the market for certain goods. While the Dutch attempts to prevent other nations from growing tulips is well known, there were similar efforts by coffee-growing regions to prevent the spread of the coffee tree. Nations guarded their coffee trees. In 1670 a smuggler strapped seven beans from Yemen onto his chest and carried them to India. When French King Louis XIV turned down a request for coffee tree clippings from a young naval officer from the colony of Martinique, that officer stole them and hid them aboard his ship. His voyage home was perilous, the ship was becalmed and the crew and passengers went without water for days—so he shared his precious allotment of these seeds. They survived the journey, and within half a century 18 million trees had been planted on Martinique and the coffee trade became a thriving industry.
Brazil grew to become the world’s largest coffee exporter after dispatching a colonel to French Guiana purportedly to mediate a border dispute. In fact, he won the affections of the governor’s wife, who handed him a bouquet of flowers at his farewell dinner—with coffee seeds hidden in the bouquet.
Among the prizes of war won by Austria after defeating the Turkish army in a 1683 battle were sacks of coffee beans. The Austrians created their own blend of coffee to be served with a cake called kipfel, which was shaped to resemble the crescent moon on the flag of the defeated Turkish army—and eventually became known by its French name, the croissant.
Proving that history repeats itself, for centuries most coffee was consumed in coffeehouses—historic versions of Starbucks—which served as centers of social and political activity. The first known coffeehouse opened in Istanbul in 1471. Europe’s first coffeehouse opened its doors in Italy in 1645. In these “penny universities,” as they became known in England because the cost of a cup was one penny, people could listen to music, play chess, watch performers, conduct business, and debate the issues of the day. Relationships that changed history were conducted in those meeting places; for example Lloyd’s of London grew out of Lloyd’s Coffee House. In some nations the political and religious discussions that became commonplace made governments wary, fearing rebellion was being plotted. England’s Charles II tried to close down the estimated three thousand coffeehouses in that nation in December 1675, issuing a proclamation that read, in part, “Whereas it is most apparent that the multitude of Coffee Houses of late years set up and kept within this kingdom … and the great resort of idle and disaffected person to them, have produced very evil and dangerous effects … (and that) in such houses divers, false, malitious, and scandalous reports are devised and spread abroad to the … Disturbance of the Peace and Quiet of the Realm … said Coffee Houses be (for the future) put down and surpressed.…” Two weeks later, after widespread protests, the ban was rescinded.
Eventually coffeehouses became so respectable that Johann Sebastian Bach conducted an ensemble at the Café Zimmerman in Leipzig, Germany, for which he composed his Coffee Cantata in 1734: “Oh! How sweet coffee does taste, lovelier than a thousand kisses, sweeter than Muscatel wine. Coffee, coffee, I’ve got to have it, and if someone wants to pamper me, Oh, just give me a cup of coffee!”
In America, the tradition of the morning cup of coffee can be traced back directly to the Revolutionary War. Fashionable teas had remained the beverage of choice for cultured Americans until the Boston Tea Party in 1773, when colonists angered by high British taxes dumped chests of tea into Boston Harbor, an act of defiance that ignited the War of Independence—and caused most Americans to prove their patriotism by switching from tea to coffee. As John Adams wrote to Abigail about stopping for refreshment after a long ride and being told by the proprietor, “‘(W)e have renounced all Tea in this place. I can’t make tea, but I’le make you Coffee.’ Accordingly I have drank Coffee every afternoon since, and have borne it very well.”
The effects of coffee have been debated for hundreds of years. In 1674, for example, English women complained that this “nauseous Puddle-water … has Eunucht our Husbands.… [T]hey are become as impotent as Age.” While at almost precisely the same moment a tract written by an otherwise unknown M.P. celebrated its virtues, “’Tis extolled for drying up the Crudities of the Stomack, and for expelling Fumes out of the Head. Excellent Berry! Which can cleanse the English-man’s Stomak of Flegm, and expel Giddinesse out of his Head.”
For much of recent history it was generally accepted that while coffee certainly had a pleasing taste and was very useful in keeping people awake and alert, it could cause some serious problems and really should be used in moderation. In fact, no one knew with scientific certainty exactly what health problems or benefits, if any, were the consequence of drinking coffee. But that began changing in the 1960s.
While most medical studies begin with a specific premise to be tested, a hypothesis, a tremendous amount of information can be gleaned from statistical analysis of information collected with no specific point of view. It’s an examination of real-world behaviors and results and is known as epidemiological research. One of the largest of these observational studies was conducted by the Kaiser-Permanente Medical Care Program. KP had been founded during World War II as a prepayment medical plan for employees of Kaiser Shipyards and had expanded coverage after the war. In many ways it was the model for the HMOs that would follow. During the 1960s KP began a study to determine which medical tests had value and which did not. This involved setting up a computerized database to store and analyze information gathered from decades of health checkup examinations. Although the computers were rudimentary, the database made it possible to glean a tremendous amount of statistical evidence concerning a variety of conditions.
One of those initial studies was essentially a search for new heart attack predictors. According to Dr. Gary D. Friedman, who believed that by analyzing that mountain of information researchers could determine which behaviors increased the risk that a person would have a heart attack, “Counting all historic queries and measurements we had compiled data on about five hundred different items and some of them would prove predictive of heart attacks. For example, we found that abstinence from alcohol predicted a higher risk for heart attacks to that seen in light or moderate drinkers. This was not a pre-study hypothesis and it led us to further explore alcohol and health.”
Another study from that same database, first published in 1992 and updated in 2006, reported an inverse relationship between drinking coffee and liver cirrhosis. This was not totally unexpected, but the extent of the impact was somewhat surprising. Coffee lowered the level of liver enzymes in the blood; astonishingly, the study found that the more coffee individuals drank, the less chance they had of developing alcoholic cirrhosis. Each daily cup accounted for a 20 percent reduction in risk. For example, people who drink a lot of alcohol could reduce their chance of developing cirrhosis 40 percent by drinking two cups of regular coffee a day and by an astounding 80 percent by drinking four cups of regular coffee a day. But I caution my friends and the lay public that this is not a license to drink an excessive amount of alcohol and then protect your liver by drinking regular coffee. It will likely protect the liver, but that amount of alcohol can damage the brain, lead to heart failure, pancreatitis, and impotence, and of course it can ruin someone’s professional career and lead to untold family turmoil.
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This was a startling discovery; the evidence was strong that coffee could reduce chances of alcoholic cirrhosis, but the analysis couldn’t determine why it was true. “Epidemiology doesn’t determine mechanisms,” explains Dr. Arthur Klatsky, a cardiologist and investigator in the Kaiser Permanente Research Division who conducted the study. “It usually shows only associations. Like most other people, I was surprised at the strength of the apparent protection. When you see something that is reduced 60 percent, 70 percent, 80 percent that is a very major reduction risk. And that’s what we found in the relationship between heavy coffee drinking and the likelihood of developing cirrhosis. But it’s very important to emphasize that the best way to reduce the risk of alcoholic cirrhosis is to limit the alcohol intake, not to cover heavy alcoholic consumption by drinking coffee.”
As Dr. Klatsky points out, the numbers tell a story, but they do so without any details. The data doesn’t report which type of coffee people drink, whether they add anything to it, whether it’s filtered, or even if it’s caffeinated or decaffeinated. All that is known is the number of cups of coffee people drink every day and how that impacts disease. Personally, Dr. Klatsky reports that he has “two cups of coffee in the morning and sometimes a cup at noon. Three is my maximum. Otherwise it keeps me awake.”
Dr. Klatsky’s research helped stir the growing interest in the health benefits of coffee. While coffee has been prized for its value as a stimulant for centuries, few people suspected it might have additional benefits. And since coffee, unlike most drugs, can’t be patented—not even by Starbucks—there had been little financial incentive for private industry to support the enormous costs of research. So most studies about the effects of coffee have been conducted by large institutions and public health agencies and paid for by the government.
Perhaps because of Klatsky’s unexpected findings about liver cirrhosis, many of the larger studies have investigated the effects of coffee on the liver. In August 2007, for example, the preeminent journal Hepatology reported that ten different studies conducted in Europe and Asia demonstrated that men and women who regularly drink coffee have a significantly reduced chance of developing liver cancer. Liver cancer is an especially virulent disease, with almost thirty-five thousand Americans diagnosed each year. Worldwide, primary liver cancer (cancer arising from within the liver) is the third leading cause of cancer mortality. One million individuals succumb to it each year. As it turns out, drinking coffee apparently greatly reduces the odds of being one of those people. The studies included approximately 240,000 people, among them 2,260 diagnosed with the disease, and showed that people who drink at least several cups of coffee daily had less than half the chance of being diagnosed with liver cancer than study participants who drink no coffee. In fact, the odds drop by 23 percent with each daily cup.
An Italian meta-analysis of sixteen high-quality studies published in Clinical Gastroenterology and Hepatology in 2013 reported that coffee consumption reduced risk of hepatocellular carcinoma, the most common type of liver cancer, by about 40 percent, adding that some data indicated that drinking three or more cups daily reduced that risk by more than 50 percent.
As in Dr. Klatsky’s cirrhosis study there was no attempt made to determine the reason for this protection, although there is some speculation that coffee affects liver enzymes.
Why or how it works remains somewhat of a mystery. What we have learned is that coffee drinkers have lower levels of liver enzymes in the blood, less liver fibrosis (scarring), a dramatic reduction in the rate of hospitalization from chronic liver disease, and, as mentioned above, a substantially lower risk of developing primary liver cancer.
Another study conducted by investigators at the Harvard School of Public Health and Beth Israel Deaconess Medical Center showed that coffee drinkers have high levels of plasma adiponectin. Low levels of plasma adiponectin have been shown to be linked with aggressive liver disease. Coffee drinkers also have low levels of C-reactive protein (CRP), increased levels of which signal a greater risk for developing atherosclerotic heart disease, which often manifests as a heart attack. Coffee’s effect on glucose metabolism may be what makes it responsible for other vitally important benefits.
While previous studies had failed to find a link between drinking coffee and prostate cancer, a 2009 study funded by the National Institutes of Health closely followed fifty thousand male health professionals for two decades and found that men who drank six or more cups of either caffeinated or decaffeinated coffee daily reduced their chances of developing advanced prostate cancer by an astounding 60 percent; in addition, men who enjoyed four or five cups saw a 25 percent reduction, and drinking three cups lowered risk by 20 percent, compared with people who did not drink coffee. Harvard’s Kathryn Wilson, one of the authors of the study, speculating on why this might be true, suggested, “Coffee has effects on insulin and glucose metabolism as well as [on] sex hormone levels, all of which play a role in prostate cancer.”
If all coffee did was reduce the risk of a variety of liver diseases it would still be very valuable, but the very promising news is that there is a rapidly growing body of evidence that it has many other real benefits. Perhaps most exciting is its potential to impact type 2 or adult-onset diabetes. Coffee, by virtue of being insulin sensitizing, meaning it improves the body’s response to insulin, decreases the risk of developing type 2 diabetes by 40 percent—if one drinks six cups of it (but it can be regular or decaf).
We are facing a worldwide epidemic of this very dangerous disease. It is estimated that almost 250 million people worldwide suffer from diabetes and that the vast majority of them have been diagnosed with type 2, which can lead to an array of serious problems. Researchers at the Harvard School of Public Health and Brigham and Women’s Hospital conducted an eighteen-year study beginning in 1980 in which they tracked 125,000 people. The results, published in Annals of Internal Medicine in 2004, were impressive: People who drink coffee regularly can significantly reduce their risk of type 2 diabetes. Men who drank six or more cups daily reduced their chances of being diagnosed with adult-onset diabetes by 54 percent; women who drank the same amount reduced their risk by about 30 percent. As lead researcher Dr. Frank Hu explained, “We don’t know exactly why coffee is beneficial for diabetes.… Coffee contains large amounts of antioxidants such as chlorogenic acid and tocopherols, and minerals such as magnesium. All of these components have been shown to improve insulin sensitivity and affect glucose metabolism.”
Those findings were confirmed by a meta-analysis conducted at Australia’s University of Sydney. A team of international researchers examined eighteen studies involving more than 450,000 participants and reported in Archives of Internal Medicine in 2009, “Every additional cup of coffee consumed in a day was associated with a 7 percent reduction in the excess risk of diabetes.”
In the world of coffee, quality is in the cup of the beholder, but for researchers it’s simply a matter of quantity. Both of these studies demonstrated that quantity makes a difference. The philosopher Voltaire was purported to enjoy as many as fifty to seventy-two small cups of coffee daily—and died in 1778 at the age of eighty-three. While that certainly seems to be a bit extreme, participants in the Harvard study who drank six or more cups daily saw by far the greatest reduction in risk, an extraordinary 50 percent, while adults who had four or five cups reduced their chances of getting diabetes by 30 percent and people who consumed fewer than four normal-sized cups daily reduced their risk by 2–7 percent. Interestingly, that Harvard study also showed that women gained no additional protection by drinking five or more cups a day.
Both the Harvard and Australian studies found different—but still valuable—outcomes when coffee drinkers chose decaf: Drinking four or more cups of decaffeinated coffee daily reduced the risk of developing diabetes by a still impressive 25 percent for men and by 15 percent for women. Clearly there are benefits no matter what type of coffee you drink—so long as you drink a fair amount of it.
Further confirming this link was an eleven-year study beginning in 1986 conducted at the University of Minnesota examining the relationship between drinking coffee and diabetes in postmenopausal women. Since type 2 diabetes most often occurs in people older than forty-five, postmenopausal women are an especially affected group. This study reported that women who drank six or more cups of any type of coffee reduced their chances of being diagnosed with diabetes by 22 percent. There are a lot of people who see that number—six cups!—and complain that if they drank that much coffee they’d be awake for the following two months, but an especially puzzling aspect of that study showed that women who drank six or more cups of decaffeinated coffee actually saw a greater reduction, 33 percent, in risk.
There are a lot of different theories as to why men and women consistently have been shown to have different responses to coffee; the present theory is that a woman’s hormones—or, more often, hormone-replacement drugs in postmenopausal women—mitigate the effect.
Another common belief is that because coffee is a stimulant, meaning it speeds up the heart, people with heart conditions should be advised to carefully limit the amount of coffee they drink. Actually, the evidence is somewhat mixed. A 2008 Nurses’ Health Study published in the Annals of Internal Medicine followed more than forty thousand male health professionals for eighteen years and reported that men who drank five or more cups of coffee a day reduced their risk of dying from heart disease by 44 percent.
According to a Beth Israel Deaconess Medical Center study published in the American Heart Journal in 2009, that reduction in risk is seen even in people who have already suffered heart attacks. The Stockholm Heart Epidemiology Program enrolled more than thirteen hundred men and women who had a confirmed heart attack between 1992 and 1994. Eight years later those patients who normally drank four to five cups of coffee daily had reduced their risk of suffering a fatal heart attack almost by half over those people who averaged less than a cup a day, while those men and women who enjoyed one to three cups of coffee daily reduced that risk by about a third.
A Harvard study conducted in collaboration with researchers from the Universidad Autónoma de Madrid investigated the possible link between coffee and strokes in women. Using data from a twenty-four-year-long Nurses’ Health Study, in which eighty-three thousand women regularly completed questionnaires about their eating habits, including coffee consumption, researchers discovered that women who drank two or more cups a day reduced the risk of stroke by 19 percent—and the more coffee they drank the greater the reduction in risk. Women who did not smoke reported even more impressive benefits: Nonsmoking women who enjoyed four or more cups of coffee a day reduced the incidence of stroke by 43 percent! This level of risk reduction is equal to the impact of some of the best-selling drugs in the world.
As has been demonstrated in other studies, it is not simply the caffeine that contributes to this result. In fact, people who chose to drink caffeinated tea or soft drinks did not enjoy the same benefits, while women who drank two or more cups of decaffeinated coffee did show a reduced risk for stroke. According to epidemiologist Esther Lopez-Garcia, one of the directors of the Harvard study, “This finding supports the hypothesis that components in coffee other than caffeine may be responsible for the potential benefit of coffee on stroke risk.”
Coffee drinkers have a substantially lowered risk of heart attacks and do not have an increased risk of cardiac arrhythmias.
Another Kaiser Permanente study investigated the long-held belief that people with cardiac arrhythmias, a rapid or irregular heartbeat, should avoid or at least substantially limit the amount of coffee they drink. The thinking is logical: Coffee is a stimulant that speeds up the heart, so people whose heart can go out of rhythm should avoid it. But in this one study, at least, the result was quite different. Dr. Klatsky and his colleagues analyzed data collected from more than 130,000 participants over a seven-year period and found that people who drank at least four cups of coffee daily reduced their risk of being admitted to a hospital for a heart rhythm disturbance by almost 20 percent. This study, presented at the American Heart Association’s fiftieth Annual Conference on Cardiovascular Disease Epidemiology and Prevention in 2010, found that the reduced risk extended to the various types of rhythm disturbance. Dr. Klatsky admitted that the results of this study were surprising: “The conventional wisdom is that coffee can cause palpitations and it can cause rhythm problems. I think, though, that conventional wisdom is not always right and the data that were available before this study do not support the idea that moderate amounts of coffee provoke rhythm problems.”
Dr. Klatsky added, “we’re not going to recommend that people drink coffee to prevent rhythm problems,” but that people who drink a moderate amount of coffee “can be reassured that they are not increasing their risk of significant heart rhythm problems.”
Regular coffee drinking also appears to reduce one’s chances of getting colon and other cancers. The 2010 NIH-AARP Diet and Health Study published in the American Journal for Clinical Nutrition, which followed almost half a million men and women for more than ten years, found that those people who drank more than four cups of coffee daily reduced their risk of colon cancer by about 16 percent. That same study also found that people who drank tea did not see similar benefits.
In 2014, a smaller study conducted by researchers from the University of Southern California’s Norris Comprehensive Cancer Center tracked the coffee consumption of 8,500 Israelis, the majority of whom had been diagnosed with colon cancer, and reported that compared with people who did not drink coffee, people who drank one or two cups daily reduced their risk by 22 percent while those who drank three or more cups lowered their risk by 59 percent. There is no scientific explanation for this. The results confirmed those from a 2007 Japanese study published in the International Journal of Cancer that found that women who drank three or more cups of coffee every day saw their risk of being diagnosed with colon cancer reduced by about half.
Additional studies have found that coffee may even cut chances of being diagnosed with other types of cancer. For example, researchers at Harvard Medical School and Brigham and Women’s Hospital analyzed data collected from 110,000 people over more than two decades and found that women who drank more than three cups of caffeinated coffee daily had a 20 percent lower risk of developing basal cell carcinoma, the most common form of skin cancer, compared with women who did not drink coffee. Men saw their risk reduced by 9 percent, but there was no association with other and more potentially lethal forms of skin cancer. Another Japanese study, this one following 38,000 people and published by Epidemiology, concluded that people who drank at least one cup of coffee a day saw their risk of getting cancers of the mouth, pharynx, and esophagus reduced by more than half.
While once again the mechanisms aren’t yet known, there is no doubt that drinking coffee regularly reduces the risk of being diagnosed with several common cancers, including primary liver cancer, colon cancer, skin cancer, endometrial cancer, and metastatic prostatecancer. There is no magic formula (this many cups has this effect on this cancer), but the impact is real and significant.
What if I told you that drinking might make you smarter? Some people, I suspect, would respond by suggesting I’d better drink more coffee. But the evidence does appear to indicate that coffee may be very good for your mental health. As Honoré de Balzac wrote almost two centuries ago, “As soon as coffee is in your stomach, there is a general commotion. Ideas begin to move … similes arise, the paper is covered. Coffee is your ally and writing ceases to be a struggle.” Numerous controlled trials have shown that coffee does seem to have a positive affect on cognitive function. It appears to be able to stimulate mood and various brain functions by blocking an inhibitory neurotransmitter in the brain. It has been shown to specifically reduce chances of being diagnosed with Parkinson’s disease and dementia, specifically Alzheimer’s.
A study published in 2000 in the Journal of the American Medical Association analyzed three decades of data from 8,004 participants in the Honolulu Heart Program and reported that people who did not drink coffee had five times more risk of eventually being diagnosed with Parkinson’s than people who consumed three or more cups of coffee a day. A 2010 meta-analysis of twenty-six studies conducted by the Center for Evidence-Based Medicine at the University of Lisbon “confirmed an inverse association between caffeine intake and the risk of Parkinson’s Disease.” These twenty-six studies concluded that regularly drinking three or more cups of coffee reduces chances of getting this neurological disease by 25 percent, and drinking more coffee further reduces that risk. And a 2007 Duke University Medical Center study of the relation of smoking, drinking coffee, and the disease stated flatly, “Individuals with Parkinson’s Disease were also less likely to drink large amounts of coffee.” Numerous other studies have shown that the more coffee you drink, the less likely it is you will be diagnosed with Parkinson’s. This is true for both men and women, although a two-decade-long study of 77,000 women found that those women not taking postmenopausal hormones saw the same reduction in risk as men, but women taking estrogens lost some of that protection if they drank a large amount of coffee.
While the evidence linking coffee to a reduced risk of Alzheimer’s isn’t as clear-cut as its effect against other ailments, there have been several good studies in which it appears to have a positive impact in preventing the onset or progression of the disease. A Scandinavian study published in 2009 in the Journal of Alzheimer’s analyzed data collected from about 1,400 people for two decades and reported that those participants who consumed three to five cups of coffee daily reduced their risk of being diagnosed with dementia or Alzheimer’s by 65 percent. While other studies showed somewhat less dramatic results, they have consistently indicated that caffeinated coffee prevents memory decline in older people and reduces the risk of developing full-blown Alzheimer’s.
Intrigued by these findings, German and French researchers reported in 2014 that regular doses of caffeine helped prevent the buildup of tau protein deposits in laboratory mice. These deposits, which clog up the insides of brain cells, are a hallmark of Alzheimer’s. This study mirrored results from a 2011 University of South Florida study, as reported in Medical News Today, that found that coffee “wards off Alzheimer’s” because it stimulates an unknown factor in a critical protein to put off development of the disease.
All the various ways in which coffee affects the brain really aren’t known; we just know that it does. It has been shown that coffee stimulates the release of dopamine, a neurotransmitter known to produce feelings of well-being. In fact, there are many researchers who believe that its ability to produce dopamine accounts for coffee’s worldwide popularity. But it does seem to have other direct ramifications: Coffee appears to offer at least some protection against clinical depression and suicide. An NIH-supported study conducted by the Department of Nutrition at the Harvard School of Public Health published in 2011 analyzed data from about 50,000 women who were free of depression when they began participating and were followed for as long as twenty-five years. “In 3 cohort studies, 2 from the United States and 1 from Finland,” investigators reported, “strong inverse associations have been reported between coffee consumption and suicide, which is strongly associated with depression.” This study found that women who drank four or more cups of coffee a day reduced their risk of depression by 20 percent—intriguingly, women who drank decaffeinated coffee or other beverages with caffeine showed almost no benefit. Data collected from 86,000 nurses from 1980 to 1990 and published in 1996 by the Journal of the American Medical Association seemed to confirm this finding by showing that women who drank four or more cups of a coffee a day reduced their risk of committing suicide by more than half.
Those who drink coffee have a lower chance of developing both Alzheimer’s dementia and Parkinson’s disease.
Not only does coffee seem to prevent or slow the loss of certain brain functions, it also may make you smarter, thinner, and improve your physical performance. As much as that sounds like a product that might have been sold from the back of a covered wagon by a snake oil salesman, there is real scientific research to support those claims. A 2008 report from the British Nutrition Foundation reviewed sixteen studies on healthy, well-rested subjects and found, “14 reported benefits relating to caffeine consumption, including improved alertness, short-term recall and reaction time. There were also consistent findings for positive mood.…” It is known that coffee causes chemical reactions in the brain that enable neurons to increase function. One result of that, as the New York Times reported in 2014, is that coffee can help increase test scores. It might not actually be making people smarter, but just be improving their power of recall and the speed at which their brain functions.
Any product that makes you thinner is bound to attract a lot of attention. Coffee can be a mixed bean where that is concerned. Caffeine is among the few natural substances known to burn fat, and small studies have reported that it can increase the rate at which the body burns fat by as much as 10 percent in obese people and 29 percent in thin individuals. It’s for that reason that just about every fat-burning supplement on the market contains a substantial amount of caffeine. Of course, it is important to emphasize that many people load up their coffee with all types of high caloric additions, and a large coffee with whipped cream, sugar, flavored syrups, and other substances can easily weigh in at more than five hundred calories—far more than it will burn. So while no one would consider coffee a weight-loss substance, black coffee or even coffee with a little milk or sweetener added can fit nicely into a healthy diet.
There is considerably more evidence that coffee helps improve physical performance. Until recently, for example, the Olympic Games Committee included coffee among its controlled substances, which meant athletes could drink only a small, designated amount. As Fitness Magazine reported in 2005, “Caffeine acts as a central nervous system stimulant, producing effects—such as increased heart rate and blood pressure—that can make you feel more alert and energetic. Caffeine can also function as an ergogenic aid, meaning that its physiological effects enhance athletic performance. Most experts agree that caffeine’s impact on the nervous system alters one’s perceived level of exertion, making your workout seem easier and allowing you to exercise longer before feeling tired.” A 2004 meta-analysis published in the Journal of Sports Nutrition that included forty double-blind studies found that caffeinated coffee increased performance on exercise tests by about 12 percent. According to Dr. Terry Graham, of Canada’s University of Guelph and a longtime researcher of the value of coffee to athletes, “What caffeine likely does is stimulate the brain and nervous system to do things differently. That may include signaling you to ignore fatigue or recruit extra units of muscle for intense athletic performance. Caffeine may even have a direct effect on muscles themselves, causing them to produce a stronger contraction.”
Also writing in the Journal of Sports Nutrition, researcher M. Doherty reported that a 180-pound male, after drinking five cups of coffee, “significantly increased muscle endurance during [a] brief, intense workout” and that for a 130-pound woman who is a recreational runner “three cups of coffee resulted in significantly greater anaerobic metabolism and improved athletic performance.”
While the mechanism isn’t known precisely, the benefits to physical performance certainly are. One major league baseball clubhouse manager reported that during a game some players will drink as many as six cups of coffee to maintain total focus and enhance success.
This increased focus and attention may help explain another apparent benefit of coffee that is especially surprising: Coffee seems to reduce the risk that an individual will die from injuries and accidents. In 2012, the New England Journal of Medicine published a study in which researchers analyzed data collected from about 400,000 people for more than a decade in the NIH-AARP Diet and Health Study and concluded, “this large prospective cohort study showed significant inverse associations of coffee consumption with death from all causes and specifically with deaths from … injuries and accidents.” This result was consistent with similar findings in several other large studies. In some cases the value of caffeinated coffee is pretty obvious: A 2013 Australian study published in the British Medical Journal tracked about one thousand long-haul truck drivers, approximately half of whom recently had been in an accident. It is well-known that fatigue is a primary cause of automobile and truck accidents. Drivers who used some form of caffeine—which included tea and energy drinks—reduced the chances of being in an accident by 63 percent. In fact, this association is so compelling that some automotive manufacturers actually have added a steaming cup of coffee icon to their dashboard warning lights; Mercedes Attention Assist system creates a driver profile that enables sensors to measure driver alertness. After a certain deviation the coffee cup icon appears, suggesting drivers are not focused and should pull over for a cup of caffeinated coffee.
Recent research also seems to indicate that coffee may help prevent gum disease and even cavities. Let me repeat that because most often the only thing people know about coffee is that it may stain teeth: Coffee may be good for your teeth. In a 2014 study published in the Journal of Periodontology, researchers at the Boston University Henry M. Goldman School of Dental Medicine examined the health data collected from 1,152 men over a thirty-year period as part of the Department of Veterans Affairs Dental Longitudinal Study and found that “[h]igher coffee consumption was associated with a small but significant reduction in the number of teeth with periodontal bone loss.” There also is some evidence that coffee will prevent tooth decay by fighting mouth bacteria. The Journal of Agricultural and Food Chemistry reported that the antibacterial properties of several chemical compounds found in coffee, especially trigonelline, stop bacteria from attacking tooth enamel. A 2009 Indian study of one thousand random participants who were followed for more than three decades—funded by several coffee associations—concluded that people who drink black coffee can significantly reduce the incidence of dental cavities, but additives including milk and sugar eliminate most of that protection.
And while there have been few human studies, the journal Molecular Vision reported in 2010 that in animal studies scientists at the University of Maryland had found that caffeine could prevent the formation of cataracts. A similar experiment conducted in Sweden in 2013, in which caffeine eye drops were used, produced the same level of encouraging results.
Perhaps not surprising is the fact that coffee appears to reduce significantly the formation of gallstones. Gallstones are small, pebble-like, hard particles that form in the gallbladder. They can obstruct a duct coming out of the gallbladder, called the cystic duct, and lead to inflammation of the gallbladder, a condition called acute cholecystitis. On occasion, the gallstones can migrate down the common bile duct and get stuck, where the pancreatic duct and the common bile duct enter the small bowel. This complication is called acute pancreatitis and has up to a 10 percent mortality rate. The Health Professionals Follow-up Study published in 1999 analyzed data collected over a decade from 46,008 men without a history of gallstone disease and reported that men who drank between two and four cups of caffeinated coffee a day reduced the incidence of gallstones by 45 percent, while those people who drank decaffeinated coffee did not see a similar result.
A companion study published three years later analyzed data from the Nurses’ Health Study—in which almost ninety thousand women participated for almost three decades—and reported that women who drank two to three cups of caffeinated coffee a day had a 22 percent lower risk of developing gallstones, and drinking even more coffee only slightly increased that protection.
There is no longer any doubt that coffee offers significant health benefits, but in many areas the reasons for that simply haven’t been found or proved. Coffee consists of hundreds of component chemicals, among them potassium, magnesium, and vitamin E, and is rich in antioxidants, especially chlorogenic acid. Coffee also contains kahweol and cafestol. These constituents have been shown to abrogate experimental, induced liver injury in laboratory animals. In fact, most people living in our part of the world get more antioxidants from coffee than from all of the fruits and vegetables they eat combined. The coffee bean is known to contain more than one thousand compounds that might have some effect on mortality. In mysterious ways these and other constituents of coffee combine to offer this varied protection. As researchers at the University of Sydney reported after concluding that coffee reduced the risk of diabetes, “Our findings suggest that any protective effects of coffee … are unlikely to be solely the effects of caffeine, but rather, as has been speculated previously, they likely involve a broader range of chemical constituents present in these beverages, such as magnesium, lignans and chlorogenic acids.”
The primary component, of course, is caffeine. Caffeine is a chemical stimulant actually found in more than sixty different plants. Chemists lovingly refer to it as trimethylxanthine. It acts mostly on the brain and the nervous system, creating a temporary boost of energy and focus. Certainly the presence of caffeine may contribute to some of the many health benefits. Indeed there is about three-and-a-half times as much caffeine in an eight-ounce cup of coffee as there is in the same sized serving of tea or cola or in an ounce of chocolate. But it is worth noting that tea and colas that contain caffeine have not been shown to have all the remarkable health benefits of coffee. While it is not generally known, there is as much or more caffeine in a single dose of common pain relievers like Anacin or Excedrin as there is in a large cup of coffee.
One of the properties of caffeine is that it gives a boost to other important chemicals. When you drink it, it is rapidly absorbed into the bloodstream and goes to work. Some researchers believe it is caffeine’s ability to constrict blood vessels, thus reducing blood flow, that contributes to its effects. By blocking a neurotransmitter named adensoine, caffeine magnifies the effect of other neurotransmitters. For example, it has been shown to increase levels of dopamine, the neurotransmitter that helps control the brain’s centers of rewards and pleasure. It injects adrenalin into your system to provide an energy boost. It appears to help regulate the levels of liver enzymes in the blood. And, as mentioned, it magnifies the effectiveness of common painkillers like aspirin and acetaminophen and helps bring rapid relief from headaches and, in some situations, asthma.
But as with absolutely everything else produced by mother nature, there are some effects of coffee that can cause problems. As the 1674 Women’s Petition Against Coffee warned, “Coffee leads men to trifle away their time, scald their chops and spend their money, all for a little base, black, thick, nasty, bitter, stinking nauseous puddle water.” And while it’s not quite that bad, coffee has been blamed for a wide variety of ailments, including stunting growth, a variety of heart problems, and even cancer. But most of those claims have been disproved.
However, there are potential health issues associated with coffee, especially with drinking more than two or cups a day. The first, of course, is that it can be addictive, meaning that once you start drinking coffee and your system gets used to it, it’s very difficult to stop drinking it—and if you do, sometimes even for a day, the physical repercussions of withdrawal can include headaches and nausea. It can make you feel unusually tired and even depressed. Those people who drink more coffee than their system can easily tolerate may become overstimulated; too much caffeine can cause nervousness, a rapid heartbeat, excitability, insomnia, and worsening heartburn. Interestingly, heartburn can also be seen with decaffeinated coffee. The reason for heartburn is that the peptides present in the roasted beans from which coffee is brewed lead to increased acid secretion by specialized cells in the stomach.
It is the effect of coffee, and for that matter any beverage containing caffeine, on the heart that has made people wary. Caffeinated coffee makes the heart beat faster, that’s a fact. But what hasn’t been demonstrated is that a rapid heartbeat will cause health issues. According to Dr. Murray Mittleman, director of the Cardiovascular Epidemiology Research Unit at Beth Israel Deaconess Medical Center, animal studies have shown that caffeinated coffee can acutely raise blood pressure, and, “[s]ince high blood pressure is a risk factor for many types of cardiovascular disease, researchers assumed that coffee would be harmful. But several studies have shown that although there is an increase in blood pressure shortly after consumption there are health benefits over the long-term. Coffee contains many active compounds, including antioxidants, that may explain how coffee lowers the risk of Type 2 diabetes, and in turn may lower the risk of developing heart failure.” Dr. Mittleman and his colleagues analyzed data from five large studies that included 140,000 men and women, most of them in Scandinavia, and reported that low levels of coffee consumption essentially had little effect on the risk of heart failure while four or five cups a day could be associated with an increased risk.
The American Heart Association points out that while there is conflicting data about the effects of drinking four or more cups a day, there is no evidence that drinking two cups causes any problem and, in fact, doing so might be beneficial for your heart.
Similar results were seen in several other good studies. In the Women’s Health Study 33,638 women older than forty-five were followed for sixteen years, and the data showed that drinking coffee could not be associated with an increased risk of atrial fibrillation.
One of the biggest concerns about coffee is that it contributes to the loss of calcium and bone density, leading to osteoporosis, especially in women. Caffeine is known to make it more difficult for your body to absorb calcium, and calcium builds strong bones. The evidence about this is mixed. In 2002 the journal Food and Chemical Toxicology reported that caffeine consumption did result in a small decrease in calcium absorption, but that minor decrease might easily be offset by adding one or two tablespoons of milk.
A Swedish study of seven hundred elderly men and women published in Nutrition and Metabolism in 2010 showed that drinking about four cups of coffee a day was associated with a small decrease in bone density in men but not in women and concluded, “This study further states that, similar to other studies, there is consistently no link between caffeine consumption and a decrease in bone mineral density in women.”
Other studies have shown that for a small number of women drinking more than four cups of caffeinated coffee a day may exacerbate the progression of osteoporosis. The National Osteoporosis Foundation recommends that women keep coffee consumption at a moderate level.
There also have been some concerns about the effect of coffee, specifically caffeine, on pregnant women, the great fear being that it affects the fetus. The American College of Obstetricians and Gynecologists currently advises that a cup of coffee a day will not increase the risk of miscarriage or premature birth. According to Dr. William Barth, chairman of the ACOG’s Committee on Obstetric Practice, “After a review of the scientific evidence to date, daily moderate caffeine consumption doesn’t appear to have any major impact in causing miscarriage or preterm birth.”
But clearly the almost universal effect of caffeinated coffee is that, like any stimulant, it keeps people awake. That can be a very good thing when you’re driving or have work to complete, but insomnia or sleep deprivation can result in some serious problems. Regular sleep is essential for good health. In addition to simply making you feel good, it provides an opportunity for various systems in your body to function optimally. According to Dr. Shelby Freedman Harris, director of behavioral sleep medicine at New York’s Montefiore Hospital Sleep-Wake Disorder Centers, “When you’re sleeping you’re regulating hormone levels, you’re regulating insulin levels, your blood pressure is being kept under control, there are a lot of things going on, and if you’re not getting enough sleep you’re throwing these things out of whack.”
The half-life of caffeine in the body is approximately six hours, meaning its effect is diminished by half in that period of time. That’s why many people can have their last cup of coffee for the day in the early afternoon and sleep quite well that night. For some people, though, even a small amount of caffeine in their system can prevent them from gaining the benefits of deep sleep.
And finally it was Balzac who pointed out another purported troubling aspect of coffee: “Coffee is a great power in my life; I have observed its effects on an epic scale. Coffee roasts your insides. Many people claim coffee inspires them, but as everybody knows, coffee only makes boring people more boring! Think about it. Although more grocery stores in Paris are staying open until midnight, few writers are actually becoming more spiritual.”
While the overall health benefits of coffee have now be proven without any doubt, the question still remains how much coffee you should be drinking. The obvious answer is no more than your system can tolerate; if it keeps you up all night or makes you nervous or anxious, you’re drinking too much. If you’re adding hundreds of calories with creams and syrups it’s probably too much. I know a man who recently celebrated his ninetieth birthday and for many years he drank an amazing forty cups of coffee and smoked two packs of cigarettes a day; as he says, “My feet went months without touching the ground.” Since then he has reduced his coffee and given up cigarettes completely and still goes to work everyday. Another person I know can hardly tolerate the one cup of coffee he drinks each day when we meet at our local coffee shop, although perhaps as Balzac surmised the coffee is good but it is the company he doesn’t tolerate well!
One reason it’s difficult to make any kind of recommendation about how much coffee it is healthy to drink in one day is the fact that not all coffee beans are created equally, and there are almost as many different ways to prepare it as there are different types. While various teas and wines have different names, usually based on their origin, taste, and effect, among most people coffee is known simply as coffee. In fact, there are two broad classifications of coffee: arabica and robusta. Arabica is mild and aromatic and accounts for about 70 percent of the world’s coffee production. Robusta is a heartier bean with a much higher caffeine content and is used primarily in blends and instant coffee. There are about seventy coffee-exporting countries, and the taste of each coffee bean is different, sometimes just a bit or as much as a great deal, depending on the soil, the amount of rainfall, and other natural variables. Kenyan coffee, for example, has a full-bodied rich fragrance with a sharp, fruity acidity, while Colombian supremo is known for its delicate, aromatic sweetness. Brazil is the world’s leading coffee exporter, followed by Vietnam, Indonesia, Colombia, and Ethiopia. In each of these countries coffee contributes significantly to the nation’s economy and financial stability. Incidentally, the world’s most expensive coffee isn’t found at your local coffee shop: it’s called Black Ivory coffee and comes primarily from Thailand. Well, actually it comes through elephants. Elephants eat arabica beans but they don’t digest them; instead these beans take several days to pass through the elephants’ digestive system, during which time they are fermenting. They are finally excreted and collected and sold at five-star hotels for about $70 a cup. Kopi luwak, or civet coffee, comes from the excretions of a civet, a small mammal found mostly in Indonesia. Because it is so expensive, starting at about $160 a pound, producers were breeding civets and keeping them caged, although there has been a movement to prevent that from happening. But I think it is quite accurate to report that with rare exceptions your daily coffee hasn’t been in any other stomachs!
The way coffee is processed and even how it is brewed will make a difference in its taste, but also may make a difference in its effect. The paper filters used to brew coffee will absorb almost all of a substance called cafestol, which is a potent stimulator of LDL cholesterol levels, while coffee made with a French press or simply boiled will contain all of the original cafestol. Each of the series of steps from picking the cherry to its being poured into your cup can affect your coffee—although because most studies are epidemiological they do not differentiate between the numerous types nor the way it has been prepared.
Recommendations about how much coffee to drink vary. Personally, I love coffee and will drink as many as four or five cups a day, usually with skim milk or black but without a sweetener. According to Dr. van Dam of the Harvard School of Public Health, as long as your body can tolerate it there are no negative effects associated with drinking up to six eight-ounce cups of caffeinated coffee (one hundred milligrams) a day. The Mayo Clinic reports that four cups “appears to be safe for most healthy adults.” The American Medical Association points out that two to three eight-ounce cups is about average but that ten cups is an excessive amount. The AMA also reminds Americans that when coffee is loaded with sweeteners and taste enhancers it can silently add to obesity. The U.S. Food and Drug Administration reports that four hundred milligrams of caffeine, found in four cups of coffee, is a safe amount of caffeine for healthy adults—then reminds people that they might also be getting caffeine from a variety of other products, including soda, chocolate, and even some gum.
So the best answer is that there is no best answer. For most Americans the amount of coffee you are drinking now is the right amount. If it doesn’t cause you any physical distress please enjoy your coffee. As the diplomat Prince Tallyrand wrote, “Suave molecules of Mocha stir up your blood, without causing excess heat; the organ of thought receives from it a feeling of sympathy; work becomes easier and you will sit down without distress to your principle repast which will restore your body and afford you a calm, delicious night.”
Fortunately for me I happen to love the aroma and flavor of coffee. For years, I have stopped on the way to work at 6:00 A.M. at a favorite java shop. I usually get a tall, dark, rich, robust coffee and sit down with three friends for ten to fifteen minutes before getting back into the car. By 5:00 P.M., I’ve had another two or three cups of this magical elixir.
Copyright © 2016 by Sanjiv Chopra, M.D., and David Fisher
