Why Black Coffee Is So Good For You & The Best Times To Drink It

Coffee is one of the most controversial beverages out there. Some swear by it, and others say you should avoid it in the name of health. So, who’s right? Is black coffee good for you or not? We dug into the science and spoke to experts to get the answer.

Before jumping into the specific health benefits of black coffee, here’s a quick nutritional breakdown of an 8-ounce brewed cup1:

Yes, coffee wakes you up—and that might be the main reason you drink it. But it can have positive effects on your health beyond that, too.

“Black coffee offers numerous health benefits as it contains more than 1,000 bioactive chemicals that can promote longevity,” says integrative medicine specialist and women’s health expert Betsy Greenleaf, DO.

Coffee is one of the most significant sources of polyphenols2 and phenolic acids in the developed world. Polyphenols act as antioxidants to protect your body from oxidative stress. This can help reduce your risk of a number of long-term health problems, like heart disease, inflammatory diseases, and cancer.

Here are some of the most significant health benefits of black coffee that have been studied by science—from brain function and cognition to gut health and weight loss:

Let’s start with the main reason many people reach for a cup of joe in the morning: It wakes you up. The science is pretty clear on this, but in one particular study, researchers found that black coffee could increase alertness and improve reaction time3 30 minutes after drinking it. It was also shown to improve overall cognition and mood at around 150 milligrams of caffeine.

In addition to these short-term effects, black coffee has also been shown to have long-term benefits on brain health and cognition. In another study published in 2021, researchers called out that not only can coffee mitigate cognitive decline, but it may also reduce the risk of developing Alzheimer’s disease4. (Interestingly, this effect seems to be more pronounced in men5.)

These effects are due to the fact that coffee acts as an adenosine receptor antagonist6. To put it plainly: Adenosine is a neurotransmitter that makes us feel sleepy. Adenosine also plays a role in your immune, circulatory, respiratory, and urinary systems, as well as your brain health.

The caffeine in coffee blocks the adenosine receptors in your body, which is why it can increase alertness and improve cognition, learning, and memory. Over time, blocking these receptors may help prevent brain diseases and other issues7, like Alzheimer’s disease and migraines, while also improving your mood8.

Caffeine also enhances dopamine signaling9 in the brain, further improving mood.

Coffee is considered cardioprotective too. Regular coffee consumption has been linked to a lower risk of coronary heart disease, stroke, and congestive heart failure10. Habitual coffee drinking has also been shown to reduce other risk factors of heart disease, like type 2 diabetes11 and obesity12.

“Contrary to the common misconception that coffee worsens blood pressure and is bad for the heart, habitual coffee drinkers have actually reported a lower risk for cardiovascular diseases and an improvement in heart health," says Greenleaf. "Furthermore, no studies have shown an increased risk of arrhythmias or a worsening of blood pressure in coffee drinkers."

Researchers pored over data from observational studies and meta-analyses and found that drinking three to five cups of coffee per day13 could decrease the risk of heart disease by as much as 15%, compared to not drinking coffee at all.

As you might already know, coffee can make you poop. According to intregrative dietitian Jessica Cording, RD, it mimics the effect of a stimulant laxative, speeding up transit time. This can be good news for those who deal with constipation and need help getting things moving.

But coffee also appears to have some positive effects on your gut microbiome, too. Research shows that coffee may help balance gut bacteria14—specifically promoting the growth of “good bacteria,” like Bifidobacterium and Lactobacillus, and decreasing numbers of potentially harmful bacteria, like Clostridium and Escherichia coli. It may also help protect the mucosal lining15 of your digestive tract.

Researchers are still trying to nail down the exact mechanisms here, but the hypothesis is that two compounds in coffee—chlorogenic acid and theobromine—can help increase the absorption of polyphenols in the intestines, which causes a synergistic effect.

"Coffee contains something called chlorogenic acid16 that also lights up your metabolism as well as your health defenses," physician and researcher William Li, M.D. explaines on the mindbodygreen podcast. 

Coffee also stimulates the secretion of stomach acid17 and other gastric juices like bile. This plays a role in balancing gut microbes, and it can reduce the risk of gallstones.

There’s also some research18 that shows coffee may speed up metabolism and help promote weight loss—or at least play a role in weight management.

“Studies suggest that coffee affects fat storage in cells, boosts metabolism, and promotes gut microbiome,19 all of which can aid in maintaining a healthy and lean body,” says Greenleaf.

This effect is largely tied to the caffeine content of coffee, with one study concluding that increasing caffeine intake could promote greater reductions in body mass index (BMI)20 and body fat, specifically.

Caffeine also seems to have performance-enhancing effects21, which is why many people take it as a pre-workout supplement. It delays fatigue and triggers alertness, which can make it easier for you to get through your workouts.

However, Cording cautions taking this finding with a grain of salt: “Some research suggested that people who drink coffee every day are more likely to get enough physical activity,” she says, adding that there's more research to be done here.

Epidemiological studies show an inverse relationship between coffee consumption and risk of diabetes. “Findings from a review of 28 medical studies22 showed that the more coffee participants drank, the less likely they were to develop diabetes. Five cups of coffee a day, for instance, could decrease the risk by as much as 26%. Even just one cup a day can lower your risk by 9%,” says Greenleaf.

Another review found that drinking up to three cups of coffee per day could reduce the risk of type 2 diabetes23 and metabolic syndrome—a cluster of abnormalities, like high blood pressure, high blood sugar, excess body fat around the midsection, and abnormal cholesterol levels that can increase your risk of diabetes, heart attack, and stroke.

While the science isn’t totally settled on how coffee can reduce diabetes risk, researchers have some ideas. One strong theory is that coffee can improve fat oxidation11 in the liver and lower the risk of fatty liver, both of which are connected to type 2 diabetes. Coffee also seems to improve mitochondrial function and lower stress in the beta cells—the cells in your pancreas that make, store, and release insulin.

But while there are plenty of health benefits of black coffee, the drink with some potential downsides too. People also tolerate it differently, so if you’re caffeine-sensitive, these side effects may not be worth it:

Yes, black coffee is overall very good for you—even with these potential downsides. However, you'll want to make sure that your body can tolerate it and be careful not to overdo it on the caffeine.

Not only does black coffee enhance cognition and focus in the short term, but drinking it can benefit your heart, gut, and brain in the long term too, as well as have a positive effect on metabolic health.

Keep in mind, we’re specifically talking about black coffee here. “Adding sugar or creamer may result in body inflammation, therefore, consuming coffee without any additives is preferable for better health outcomes,” notes Greenleaf. Putting too many additives in your coffee can also lead to unwanted weight gain.

If you can’t tolerate black coffee, or you just don’t like the taste, you can still reap the benefits with some healthier strategic mix-ins (which we'll get to later).

Ready to reap some of the benefits of black coffee? There are several ways you can make it—each affecting its flavor and caffeine content.

Brewed coffee is made by pouring hot water onto ground coffee beans and allowing it to brew. Drip coffee, percolators and a French press all fall into this category. Brewed coffee has about 92 milligrams30 of caffeine per 8-ounce cup.

Espresso is made by forcing hot water through a compressed “puck” of coffee beans using high pressure. The result is a much more concentrated coffee that contains 62 milligrams31 of caffeine per ounce.

Cold brew coffee is similar to brewed, but the extraction process involves using cold water instead of hot. Because cold water isn’t as effective at this extraction, the ratio of ground coffee to water is often greater—sometimes double. Because of this, some cold brews can have almost 200 milligrams of caffeine or more per 8-ounce cup.

Decaf coffee is made by soaking regular coffee beans in a mixture of water and solvents to remove the caffeine content. Decaf coffee has about 2.5 milligrams32 of caffeine per 8-ounce cup.

While you’ll want to skip commercial creamers and sugar, here are some things you can add to your black coffee that shouldn't get in the way of its health benefits:

The best time of day to drink coffee really depends on why you’re drinking it. If you need a pick-me-up right when you wake up, drinking it in the morning can be beneficial. 

However, drinking coffee on an empty stomach can be aggravating for some people, so you may want to wait and have it with breakfast.

“There’s a tendency to think it’s virtuous to only drink black coffee before eating anything, but coffee is not the same as breakfast,” says Cording. “While it’s perfectly fine to have black coffee on an empty stomach if you feel good doing it, each person is unique in terms of what they need to thrive.”

Some health experts, such as neuroscientist Andrew Huberman Ph.D., suggest that many people would also benefit from delaying their caffeine intake at least 90 minutes after waking up. This gives your body time to wake up naturally and it may help you get through the afternoon without needing more coffee (which will benefit your sleep).

If you want to reap the potential performance-enhancing benefits of caffeine, want to drink it about 30 minutes prior to a workout.

It’s also a good idea to stop drinking caffeinated coffee at least six hours before bedtime34 and cap your daily caffeine intake at around 400 milligrams (4-5 cups of black coffee) per day, according to Cording. Otherwise, it has the potential to disrupt your sleep.

Black coffee is a rich source of antioxidants and drinking it can have several positive effects on your health. But if you feel anxious or jittery after drinking coffee, or it bothers your stomach, don’t force it. If you want the full benefit of coffee, skip mix-ins like creamer and sugar, which can contribute to inflammation, and drink your coffee black or with functional mix-ins like mushrooms or collagen powder.