A cup of coffee can give you the energy to face a new day. And it's just possible that it might lengthen your life as well.
People who drink more coffee tend to live longer than those who drink less, according to a study of more than 500,000 Europeans over a 16-year period. The study results were published last month in the Annals of Internal Medicine.
The findings echo those of earlier research. A Harvard T.H. Chan School of Public Health study that found that people who drink either caffeinated or decaffeinated coffee are at lower risk of death from illnesses such as cardiovascular disease to Type 2 diabetes.
However, before you fill your mug to the brim, know that other research has sounded warning signals about drinking too much coffee.
For example, drinking very hot beverages is likely associated with cancer of the esophagus, according to the International Agency for Research on Cancer.
In addition, a Mayo Clinic study found that men under the age of 55 who drink an average of four cups of coffee or more each day actually are at a higher risk for premature death.
So, what's the real scoop on that cup of joe?
How coffee can harm your health
It's true that drinking too much java can negatively impact your health, says Jennifer Bruning, a registered dietitian nutritionist and spokesperson for the Academy of Nutrition & Dietetics.
For example, caffeine can cause blood pressure to rise over the short term. "Those diagnosed with hypertension or the elderly may be more susceptible to this effect," Bruning says.
People prone to anxiety also might find that caffeine worsens their symptoms.
Pregnant women should avoid drinking too much coffee, which has been linked to numerous negative health impacts in the mother and child, including birth defects.
"Avoiding caffeine as much as possible is your safest course of action," says the American Pregnancy Association.
Others also should at least limit their intake of coffee.
"Some people with gastroesophageal reflux disease find that their symptoms are antagonized by caffeine," Bruning says. GERD can lead to other health problems, such as esophageal cancer.
How coffee can help your health
On the other hand, coffee has been shown to improve some aspects of health.
Coffee is rich in antioxidants, which have been linked to a reduced risk of cancer, heart disease, diabetes and age-related degenerative disorders.
It also provides more obvious benefits, such as providing an energy boost and enhancing mental clarity.
Bruning notes that adding milk to coffee can give you an extra dose of protein and calcium. Americans typically get too little calcium in their diet, she says.
"Cafe au lait or lattes with skim milk are a great choice for those who want to get maximum health benefits from their daily cup," she says.
The key to getting these health benefits – and avoiding potential health risks – is to drink just enough coffee. Typically, that's no more than about 400 milligrams of caffeine a day, Bruning says.
The Mayo Clinic also recommends limiting yourself to 400 milligrams of caffeine, and says that amount is equivalent to:
- Four cups of brewed coffee
- 10 cans of cola
- Two "energy shot" drinks
Some people are more susceptible to the effects of caffeine than others, the Mayo Clinic notes. For such individuals, even just a single cup of coffee per day might be too much.