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Diet and Nutrition

Is coffee good for you?

Diet and Nutrition

A cup of black coffee on a wooden table surrounded by coffee beans and fresh green leaves.
Drinking coffee in moderation has been associated with a lower risk of heart failure and stroke, among other potential benefits.

If you’re one of those folks who can’t face the day without a cup of joe, here’s a bit of good news: There’s very little evidence that coffee is bad for you. In fact, it might actually be good for you, in moderation. 

In 2012, the American Heart Association (AHA) published findings from a meta-analysis that drinking coffee in moderate amounts might help lower the risk for heart failure. The largest decrease in risk was observed in individuals who drank four cups of coffee daily. At the AHA’s Scientific Sessions 2017, researchers presented updated findings that showed an association between drinking coffee and reduced risk of heart failure and stroke. This is not surprising, as coffee has a long history of benefits for people across the world.

Coffee: The social common denominator

The history of coffee is as robust as the beverage itself. According to the National Coffee Association, coffee originated in Africa, then made its way to the Middle East, arriving in Europe in the 17th century. It was in Vienna, Austria, where coffee first established a pivotal role in ongoing social and political movements.

Coffeehouses developed rapidly in Europe and in the Middle East as points of convergence of thinkers from all backgrounds – individuals (learned or not), academics, aristocrats, and, for the first time, commoners – came together to discuss art, religion, social events, and politics. In most countries, with Germany as an exception, women were not allowed to participate in coffeehouse-based events. These conversations became so enlightening and powerful that governments and religious leaders attempted to ban coffeehouses to reduce the risk of patrons speaking ill of their power. However, coffeehouse culture had become so ingrained across the continent that the royal ban in the UK lasted just one week.

Coffee, its consumption, and the multidimensional social interchange triggered by its consumption, has been a powerful factor contributing to norms in current-day society. In fact, the social health benefits of coffee are clear – benefits no longer relegated exclusively to men. A mutual love of the beverage can bring people together to exchange ideas and rise against adversity. And today, we know that the beverage may offer physical health benefits as well. 

“Enjoying coffee in moderation is safe for most people who follow a heart-healthy lifestyle, and it might, in fact, be a health-promoting strategy.”

– Joseph A. Hill, M.D., Ph.D.

How is coffee potentially good for you?

Coffee is a complex beverage that consists of more than 200 different molecules. Some of those molecules are flavonoids – a type of antioxidant that might have heart-healthy or immune-protective properties. Research is underway to determine whether antioxidants really affect our health in a positive way and how the flavonoids in coffee compare to those in fruits and vegetables.

A 2012 study suggested a decrease in mortality in people who consume more coffee. Keep in mind this was an association study only – other lifestyle factors that affect mortality were not considered. Much of the current research into the potential health benefits of coffee measures the association of coffee consumption with health benefits rather than whether it causes benefits. For example, one might associate using a cane with growing older, but using a cane doesn’t cause aging. Similarly, the association between coffee consumption and decreased mortality likely involves, at least to some extent, other lifestyle factors such as eating a healthier diet, exercising more regularly, or having better access to health care.

Caffeine also might promote insulin sensitivity. A 2007 study suggested that 200 mg of daily caffeine intake (one 8-ounce cup of coffee contains 80 mg to 100 mg of caffeine) can reduce the amount of insulin required to turn calories into energy – potentially reducing the risk for type 2 diabetes. Also, the more insulin circulating in our bodies, the hungrier we tend to feel. However, there is not enough research-based evidence to suggest that coffee helps people lose weight, nor can we say for certain that drinking coffee prevents diabetes.

Studies over the past two decades also link coffee consumption with decreased risk of prostate cancer and endometrial cancer. Again, these epidemiological studies suggest a link between coffee and reduced risk but don’t exclude other factors that travel with coffee consumption, such as lifestyle and genetics, which together could play a part in overall risk.

Coffee also has been examined for its benefits in athletes. The American College of Sports Medicine has found that caffeine consumed prior to exercise increases athletic performance for prolonged endurance exercise or short bursts of intense exercise in elite or serious recreational athletes. But how caffeine works to improve performance is not fully understood.

And, of course, most of us are familiar with the mental effects of coffee. As one Civil War soldier wrote in his diary, “Nobody can soldier without coffee.” Coffee provides a number of useful benefits to help us all get through the day, including:

  • Faster reaction speed
  • Improved job performance due to lessened fatigue
  • Improved mood and alertness 

How is coffee potentially bad for you?

The good news is that there isn’t much evidence that plain, black coffee is bad for you. However, that does come with a few considerations. If you’re sensitive to caffeine, coffee could well affect you differently than it affects others. For some health conditions, including heart issues, your doctor might suggest you avoid or limit your caffeine intake. That includes coffee, chocolate, green tea, and other sources of caffeine. That said, a study published in January 2016 found that for those with healthy hearts, drinking or eating caffeine in moderate amounts will not cause arrhythmia or heart palpitations.

But there could be other serious effects of drinking coffee. A 2001 study uncovered a 20 percent increase in urinary tract cancer risk in people who drink coffee but not in individuals who drink tea. The same findings were noted in a 2015 meta-analysis. For individuals with a family history of urinary tract cancer, it might be wise to avoid coffee until further research proves or disproves these associations.

Coffee is a mild diuretic – drinking too much coffee can contribute to dehydration. A few cups a day won’t make you dehydrated. However, if you consume coffee beverages for an energy boost during your workout, you might lose more sweat than normal. Some people sip coffee throughout the day when they really ought to be drinking water. If you drink mostly coffee and little water all day, every day, that is likely not an optimal way to hydrate your body.

Studies touting the health benefits of coffee almost always refer to “black” coffee – no cream, sugar, flavored syrups, or whipped topping. But that’s not how many of us drink coffee. It’s easy to get carried away and add a few hundred extra calories to your coffee without realizing it. Single-serve plain liquid creamers contain 15 calories each, and single-serve sugar also contains 15 calories per packet. That adds up fast, considering many coffee drinkers use more than this per cup. Some gourmet coffee drinks pack 300 to 400 calories for a small serving!

Plain black coffee, on the other hand, contains just 2 calories per 8-ounce serving, and a 1-ounce serving of plain espresso contains just 1 calorie. Consuming excess calories, especially empty calories with no nutritional value, contributes to weight gain and type 2 diabetes. Opt for coffee with as few add-ins as possible.

If you can’t tolerate black coffee, flavored coffee beans are a good option to add taste without adding calories. Skip sugar and try sugar-free syrups or add cinnamon to your coffee for a kick of flavor. You also might consider using skim milk or unsweetened almond milk instead of creamer or whipped topping to save on calories and add nutritional value. 

How much caffeine is in my coffee?

Earlier, I noted that an 8-ounce cup of coffee has about 80 mg to 100 mg of caffeine. The variation greatly depends on the type of bean or grounds you brew, as well as on how you prepare the beverage:

  • Espresso machines: An espresso maker pushes water through the grounds as fast as possible. This extracts many of the flavorful compounds and leaves much of the caffeine behind. Surprisingly to some, espresso has less caffeine than regular coffee when serving sizes (1 ounce versus 8 ounces) are compared.
  • Percolators: This is the type of machine my parents used to have, which runs water through the grounds over and over. A percolator picks up a lot of caffeine because of the multiple passes.
  • French press: This method is similar to the percolator and also delivers a lot of caffeine. It’s called a “press” because, after infusing the grounds with hot water, you press the grounds with the machine’s plunger to separate them from the water.
  • Drip machines: These machines are in between. The caffeine extracted as the water zips through the grounds emerges right into the pitcher, but many of the flavonoids stick to the paper filter. However, if you use a steel filter, the flavonoids follow the water through to the pitcher.
  • Single-serve coffee makers: These work similar to espresso machines, which zip the water through the grounds quickly.

For the average, healthy person, the AHA recommends limiting caffeine consumption to 400 mg or less daily – to stay within that range, that’s about four 8-ounce cups of coffee. Enjoying coffee in moderation is safe for most people who follow a heart-healthy lifestyle, and might, in fact, be a health-promoting strategy, both socially and physically.

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