Coffee is a very popular drink. Chances are that you also regularly drink a cup of coffee. But are you also confused by the enormous amount of research on coffee that often seems quite contradictory? Then you've come to the right place with this new article about coffee.
In fact, coffee is an important source of antioxidants in the Western diet. It is also associated with many health benefits, including a reduced risk of type 2 diabetes and liver disease. Here's what you need to know about coffee's—mostly beneficial—health effects.
While older studies of coffee suggested it could lead to health problems, recent research provides strong evidence that drinking coffee actually has several health benefits.
When in 1981 in the New England Journal of Medicine In a study linking coffee to pancreatic cancer, the author, Brian MacMahon, spent the next few days making endless phone calls from reporters. Coffee is extremely popular among most populations, which shocked the world at the time because of the relationship with cancer he mentioned.
As for the cancer, however, he was wrong: the study design turned out to be flawed. A wealth of empirical evidence has since made a strong case for the health benefits of drinking coffee, actually a habit that is familiar to many of us.
The many health benefits of coffee
According to recent research, coffee may even be good for you. “The general evidence has been quite compelling that coffee is healthier than harmful in terms of health outcomes,” said Frank Hu, chair of the Division of Nutrition at Harvard's TH Chan School of Public Health. For most people, moderate coffee consumption can easily be incorporated into a healthy diet.
He confirmed what recent studies have found: moderate coffee intake is linked to a lower risk of type 2 diabetes, heart disease, liver and endometrial cancer, Parkinson's disease and depression.
People who drink coffee may actually reduce their risk of death, although it is not yet clear exactly what role the drink plays in our longevity. And a moderate amount of daily coffee, according to his study and a number of large mortality studies, is still quite generous at about two to five cups a day.
“By staying within a reasonable intake, the benefits really seem to outweigh any adverse effects,” says a caffeine and coffee researcher at Northwestern University's Feinberg School of Medicine. She has studied coffee extensively, in particular the role of genetics in coffee consumption.
The key to the power of coffee
Coffee is probably best known for that one natural stimulant—caffeine—that gives people energy and keeps them alert throughout the day. Caffeine binds to adenosine receptors, making you feel less sleepy and reducing its depressed effect.
But it is unlikely that the caffeine in the coffee alone is responsible for the health the drink provides. “Coffee is a complex, plant-based drink that not only contains caffeine, but also hundreds of bioactive compounds.” That makes it difficult to distinguish the effect of the individual components of the drink.
This popular morning drink is also high in antioxidants, polyphenols and are likely to provide several health benefits. Some polyphenols have been found to fight inflammation and protect against certain diseases. Studies have suggested that some of the same reductions in diabetes and heart disease are associated with decaf coffee — meaning it's not just the caffeine in the coffee.
Why previous studies were wrong
For years, researchers have linked coffee to an increased risk of developing conditions that we now believe may help counteract them. Studies from the 1980s and 1990s, such as the one by MacMahon mentioned above, pointed to coffee as a suspect in everything from heart disease to asthma.
Now we know that there were likely several explanations for the early coffee studies that exaggerated or even misinterpreted its risks. For starters, researchers now say, a number of studies followed groups of people who drank coffee and also smoked, leading researchers to believe that coffee explained the adverse effects now associated with cigarettes.
Today, scientists use more sophisticated sampling and statistical methods. “We addressed many of those limitations of previous studies. Sometimes the public gets really frustrated with changes in diet and health, probably because what we knew 30 years ago is different from what we know now, and our methods are constantly improving.”
The old claims about the dangers of coffee have been largely refuted by more recent studies involving larger groups of people and taking into account those external factors (so-called 'confounders'), such as smoking, that can skew the results.
According to the researcher, everything that people consume a lot will come under scrutiny. “In the past, I think a lot of people thought, 'Oh, coffee is so good, there must be something bad about coffee'. So I think the good news is that coffee actually has health benefits for most people.”
It matters how you drink coffee
If you do choose coffee, the preparation is important. Experts believe that coffee brewed with a paper filter is the preferred brewing method. Other methods of making coffee including espresso, French press (cafetiere) or boiled Turkish coffee, are considered "unfiltered" even when strained through a metal filter. Unfiltered coffee has been linked to a higher death rate and may contain compounds called diterpenes that increase levels of "bad" cholesterol, or LDL.
While it may be tempting to assume that coffee's health benefits apply to a typical Starbucks drink, it often doesn't. The experts often refer to coffee in its most basic form: drip coffee, Chem-X, or pour-overs with little added cream or sugar—no venti java chip Frappuccino with extra whipped cream or a Dunkin' caramel macchiato. Drinks like these are high in added sugars and calories. However, drinking regular coffee instead of these sugar-sweetened drinks, or other drinks such as soda or fruit juice, has positive health effects.
There are few risks, but they exist
Coffee may provide a number of health benefits over time, but certain groups should approach consumption carefully. Not much is known about the effects of coffee on children. Meanwhile, caffeine appears to have a negative influence on pregnancies. Therefore, people who are expecting are usually asked to limit their coffee intake to 200 milligrams per day, the equivalent of about two cups. And for some, such as those with panic or anxiety disorders, drinking too much caffeine or coffee can cause anxiety or other unwanted side effects in them.
But how come when it comes to coffee, coffee can keep one person up all night while sometimes barely affecting another person's sleep. Researchers say there is a complex relationship between genes and caffeine metabolism, or how quickly the body processes caffeine. It has been investigated how certain gene variants influence this process. To complicate matters, this response can vary across different populations that may have evolved to tolerate more or less caffeine.
Is coffee addictive and does it matter?
If you asked the 62 percent of Americans who drink coffee every day to quit tomorrow, you'd probably get a resounding "no." But whether people can become addicted to coffee, or caffeine in particular, really depends on how one defines drugs and addictions, for example.
'Caffeine use disorder' is featured in the latest edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM) defined as a condition, but does not meet the 'Drug Abuse' and 'Substance Dependence' criteria, and is not recognized as a clinical condition. But an international classification system, ICD-10, does count – they call it 'caffeine dependence syndrome'.
This leaves the coffee in a somewhat unusual position. It has well-defined withdrawal symptoms, such as headache, fatigue, difficulty concentrating, and can lead to tolerance and cravings, but is unlikely to be associated with other features of substance abuse and dependence, such as absence from significant social or work situations, use in physically hazardous situations, or legal issues. By equating caffeine addiction with more serious substance use problems, they could be reduced, one of the researchers says.
While the effects of an addictive substance shouldn't be ignored, experts say people generally tend to moderate caffeine consumption by cutting back on coffee when they experience negative effects. “Based on our genetics, we're all in line with how much caffeine we can tolerate,” one says. “Many of us are well aware of the effects of caffeine, which is why we moderate our coffee consumption sufficiently on our own.”
We've clearly come a long way from the coffee panic of the past few decades and now know that we can handle a few daily cups – and might even be really good for us!
Sources include BBCGoodFood (link), Discover Magazine (link), Harvard (link), HealthLine (link)
