MCTThere’s a reason McIntyre Library offers free coffee when students are cramming for final exams – it keeps them alert. But research shows that’s not the brew’s only benefit.
Half of all Americans – that’s half of the total population, not just adults – drink coffee, said Joe Vinson, a chemistry professor at the University of Scranton (Pa.).
But over the last few decades, tea has been gaining ground. According to the Tea Association of the United States of America (TAUSA), U.S. tea sales have climbed from $1.8 billion in 1990 to $6.5 billion in 2006, and green tea accounts for much of the jump.
In 2006, the Beverage Guidance Panel at the University of North Carolina put unsweetened coffee and tea on Level 2 of its recommendations for Americans’ beverage intake, second only to water. So which should you choose? Vinson, who has studied both beverages, said they both have their advantages.
Coffee may prevent diabetes, Parkinson’s
Junior Jodi Neuman said she prefers coffee over tea.
“I just like the taste of it better, because tea is too bland for me,” she said.
Coffee packs more antioxidants than fruit and even green tea. It’s the biggest source of the disease-fighting chemicals in the American diet, Vinson said. But he cautioned that fruit gives “more bang for your buck,” providing vitamins, fiber and other nutrients.
Coffee has its drawbacks. It can cause heartburn and worsen anxiety, and large amounts can temporarily raise heart rate and blood pressure.
“Too much isn’t good for you in the long term,” Vinson said.
Despite the pitfalls, studies suggest the drink has disease-fighting properties. The American Journal of Clinical Nutrition linked coffee consumption with reduced risk for Type 2 diabetes and Alzheimer’s disease.
Studies in the past five years have shown it may help prevent colon and liver cancer. A study released this month in the Archives of Neurology found that coffee may protect people from Parkinson’s disease by slowing the depletion of dopamine in the brain. Vinson said more research is needed to draw solid conclusions about why coffee has these effects.
“We know that coffee is good for your brain,” he said. “Certainly we do.”
Tea may help heart health
Green tea is the least processed type of tea and packs the most antioxidants. It should be brewed at 185 degrees to get the most benefits, said Vivian Swift, spokeswoman for TAUSA. White tea, which is made from the tip or bud of the tea leaf, should be brewed at 165 degrees. Black tea is more oxidized and should be brewed as close to 212 degrees as possible.
According to WebMD, antioxidants make up a third of the weight of green tea leaves. Antioxidants and polyphenols in tea may help fight cancer, though the Food and Drug Administration doesn’t support this claim.
ECGC, an antioxidant in tea, has been shown in animal studies to slow plaque buildup in arteries. Green tea may also help raise “good” HDL cholesterol and lower “bad” LDL cholesterol. Vinson said people with a family history of heart disease should consider drinking it.
The catch? Studies show you have to drink a lot of it, anywhere from three to 10 cups a day, to reap the benefits.
Both brews bring the buzz
Coffee and tea deliver different levels of caffeine. A 12-ounce cup of brewed coffee packs about 143 milligrams while 12 ounces of green tea has about 45, according to the Beverage Guidance Panel’s Web site. The panel recommends a limit of four cups of coffee or five to six cups of tea daily.
Senior Jeff Hornung drinks three to five cups of tea a day.
“I like tea better because you can drink more tea without drinking too much caffeine,” he said. “It’s hard to overdo it with tea, where it’s really easy to overdo it with coffee.”
Vinson said caffeine is good for your brain.
“It perks you up – (it) improves your short term memory, he said. “It helps you to think under pressure and perform complex tasks.”
Vinson recommends that students consume caffeine and glucose before an exam.
“Don’t take a test, ever, without some caffeine,” he said.
The caution, he said, is that caffeine can be habit-forming and large doses are counterproductive when it comes to staying focused. He recommends sticking to one or two cups of coffee a day.
Susan Nitzke, a professor of nutritional sciences at UW-Madison, agreed.
“I think students should carefully monitor how their bodies and their mental capacity react when they drink coffee and tea and then time their intake accordingly,” she said.
Think when you drink
If you’re not a coffee or tea drinker, don’t feel you need to fire up the coffee pot or the tea kettle just yet.
Too much coffee or tea can replace other healthy beverages such as milk, Nitzke said. She and Vinson both said fruits and vegetables are essential to a healthy diet because they offer more than just antioxidants.
And not all the evidence on health benefits is conclusive. Some comes from animal studies that haven’t been confirmed in humans. Researchers are still trying to understand why coffee and tea have some of these benefits, Vinson said, and much more investigation is needed.
Nitzke said that just as with food, the bottom line is portion control and balance.
“I think the popular message of the day in nutrition is about antioxidants,” she said. “So the fact that coffee and tea have antioxidant benefits is certainly true, but that doesn’t mean that you need to drink coffee or tea to have antioxidants in your diet. Drinking coffee and tea certainly cannot make up for poor choices in the rest of your beverages.”
