The debate between coffee and tea isn’t quite as old as the beverages themselves, but answering the question has led to ample studies from around the world on the benefits of each.

The takeaway: The coffee bean and tea leaf are both packed with natural compounds that can calm inflammation, lower stress, and boost your health.

“Coffee and tea as beverages have a lot of benefits, particularly from the polyphenol side,” said Arpita Basu, a professor in the Department of Kinesiology and Nutrition Sciences, housed within UNLV’s School of Integrated Health Sciences. “The polyphenols are the most abundant type of plant-derived compounds, and they are widely present in teas and coffee beans.”

For coffee and tea drinkers, that means your morning cup is not only mentally soothing, it is filled with nutritional benefits. 

Green Tea

Humans have been drinking green tea for more than 4,000 years, and it remains one of the most popular beverages in the world.

A registered dietitian and researcher, Basu has been studying the health benefits of green tea for nearly two decades. 

She published her first research paper on green tea in 2007, when she and her colleagues noticed its popularity as a weight-loss supplement. Her research shows that drinking four cups of green tea each day can lower cholesterol, body weight, and BMI. It can also improve cardiovascular health, especially in adults at risk for developing type 2 diabetes.

“Green tea has also been shown to reduce stress levels,” Basu said. “Metabolic syndrome and most of these chronic conditions have oxidative stress as one of the main disease-causing pathways.”

Tea leaves are filled with antioxidants, which help the body’s immune system as the first line of defense against ailments and diseases.

Green Tea vs. Black Tea 

Green tea is the purest form of tea leaves, Basu added, noting that the oxidation and fermentation procedures to make black tea greatly reduce the antioxidant levels from the tea leaves. Even so, black tea has a rich flavor and still contains plenty of benefits and should be the preferred drink for people who may not like the taste of green tea. 

The presence of tannins, a bitter compound found in both green tea and coffee, can interfere with the body’s absorption of minerals. This means people who are anemic or who suffer from iron deficiencies must be careful about drinking large amounts of tea, and especially with meals, which may affect iron absorption.

Basu prefers to drink her green tea in the mid-morning and early afternoon and cherishes the mental benefit that comes from her daily ritual.

“I’m getting my water and the maximum number of polyphenols,” she said. “A lot of polyphenols can cross the blood-brain barrier, which can affect your mind and your mood. It is a stress reliever.”

Coffee

Coffee beans are packed with polyphenols, flavonoids, and phenol acids, according to Samantha Coogan, a registered dietitian and director of the didactic program in nutrition and dietetics within the kinesiology and nutrition sciences department      

“Coffee certainly has antioxidant benefits,” she said. “There’s going to be different antioxidant availability between a dark roast and a light roast (with light roasts retaining more due to less roasting/processing at higher temperatures), but they all have their benefits.”

For those who begin their day with a cup of coffee, Coogan recommends drinking water before taking a sip from your mug or thermos.

“Coffee is a diuretic, so you’ll be going to the bathroom a lot and needing to hydrate more,” she said. “The interesting thing is that even though coffee is a diuretic, you can still count that water toward your intake for the day.”

A recent study from the National Institutes of Health found that people who drank their coffee before noon had better cardiovascular health than those who drank it later in the day. 

Caffeine consumption later in the day, depending on how the body responds to it, can alter sleep patterns. An 8-ounce cup of black coffee has nearly 100 milligrams of caffeine, which can make sleeping more difficult and could also lead to cardiovascular issues if you’ve not built up a tolerance to the caffeine. 

“If your coffee is caffeinated, I’d say give it at least four hours before you go to bed,” Coogan said.

Pair Your Coffee with Food

For those who add excess creams and syrups to their coffee, Coogan recommends pairing it with proteins or healthy fats to slow down the carbohydrate digestion from the sugary syrups. 

“You can have your coffee hot, cold, or iced, the temperature doesn’t matter. What’s going to affect your drink is what you add to it,” she said. “And depending on the person, it can affect their blood sugar in a negative way if there isn’t anything to offset the sugar they’re consuming. The acidity of the coffee can also be inflammatory, so it’s best to not drink coffee on an empty stomach.”

Like green tea, coffee offers the most optimal health benefits when consumed in its natural state.

“There’s this perception that coffee is bad for you compared to tea,” Coogan said. “A lot of people say that when they’re sick or they’re trying to lose weight, they replace coffee with tea. But you can still get the same benefits if you switch to black coffee.”

Basu said adding a teaspoon of sugar, approximately five grams, is fine to add to your drink without having to worry much about the calories.

The excessive amount of cream and sugar we add to our beverages is a much bigger issue.

“If you add too much milk or creamer, it can make a lot of those coffee and tea polyphenols unavailable,” she said. “The general population in the U.S. does not have great cardiometabolic health, so we need to be careful with how much of these creams and sugars we add to our drinks.”

Coogan, who prefers an iced latte when she goes to a coffee shop, said she enjoys the sensation of coffee more than the taste.

“For me, coffee is more of a ritual, and I think it’s like that for a lot of people,” she said. “As a dietitian, even if it’s just placebo giving you that little dopamine hit to satisfy your craving, I say go for it. But if you drink it with a lot of added sugar, make sure you drink it with protein-rich foods and/or healthy fats.”