Special Report: The truth about coffee
Asheville, N.C. (WLOS) —
Coffee is served up more times a day than any drink in the world, aside from water. How much you should drink brews debate.
"We've gotten conflicting data," said Dr. William Hathaway, a cardiologist and Mission Health's chief medical officer. "Some of the trials say coffee is good for you; some of the trials say coffee is bad for you."
A study presented this year at the European Society of Cardiology Congress found that drinking up to 4 cups of coffee a day may be adding years to your life, by lowering your risk of death over the next 10 years.
However, a 2013 study from the Mayo Clinic determined people under 55 who drink more than four 8 ounce cups of coffee a day raise their risk of dying from all causes.
So, with a seemingly conflicting conclusion, which is it?
"None of the trials are what we call Grade-A super high-class trials," insisted Hathaway, who reviewed both studies related to caffeinated coffee.
"We have scientific reasons to think moderate doses may be helpful for you," he said. "It decreases insulin resistance and has some inflammatory effects that theoretically is appealing."
"There are these phytochemicals in tea and coffee that do help in different cancer-fighting free radical things," added Elizabeth Holes, a registered dietitian.
Holmes says problems arise when people consume more than 400 milligrams of caffeine per day or in excess of four cups of coffee per day. Hathaway agrees and adds that heavy coffee drinkers tend to engage in UNHEALTHY behaviors, something the 2013 study implied.
"Coffee drinkers tend to have a higher rate of cigarette smoking than non-coffee drinkers," he explained. "Then, there's (also) a weaker association of alcohol use associated with coffee drinking and smoking."
Holmes added, "If you're consuming a lot of caffeine and not sleeping and overworked and overstressed and that caffeine is helping you get through the day, then the sleep and the stress is most likely what's harming you."
"I would say the preponderance of the evidence suggests that 2 to 3 cups of coffee is not harmful to you unless you have palpitations and arrhythmia and know you feel bad," said Hathaway.
Mission employee Jaime Taylor, 37, did feel bad and quit drinking caffeinated coffee cold turkey three years ago on the advice of her endocrinologist.
"It was the caffeine that was causing my blood sugar to spike in the afternoon that was causing me to feel like I needed a nap or causing me to feel very weak and my glucose levels would go very low," she recalled.
"Some people -- a specific population -- may be very sensitive to caffeine," said Holmes.
"I feel so much better; my blood sugar is much more regulated throughout the day," Taylor explained.
She now drinks only decaffeinated coffee, but for those who insist on caffeinated:
"Once you reach a certain threshold, you tip into having negative side-effects," said Holmes.
"More than four cups a day: too much, not needed," said Hathaway.
"Who needs that?" he asked. "It's just a risk not worth taking.