Good news for coffee lovers: Benefits outweigh the cons
New evidence shows java drinkers are a little more likely to live longer. Regular or decaf, it doesn't matter.
People who drink up to six cups a day have a lower risk of dying, according to a study by the National Institutes of Health and the AARP.
The study of 400,000 people is the largest ever on the issue, and the results should reassure any coffee devotees who think it's a guilty pleasure that may do harm.
"Our study suggests that's really not the case," said lead researcher Neal Freedman of the National Cancer Institute, a division of NIH. "There may actually be a modest benefit of coffee drinking."
No one knows why. Coffee contains 1,000 things that can affect health -- from helpful antioxidants to tiny amounts of substances linked to cancer. The most widely studied ingredient -- caffeine -- didn't play a role in the new study's results.
Published this month in the New England Journal of Medicine, the study adds to the on-going research on coffee's effects, said Dr. Donald Hensrud, chairman of preventive, occupational and aerospace medicine at the Mayo Clinic, Rochester, Minn., and a native of Grand Forks.
"Coffee has a reputation as something we should stay away from," he said. But this and other recent studies show "the health benefits generally outweigh the risks."
Earlier studies stirred fears that coffee could increase one's risk of heart disease by raising LDL, or bad cholesterol, and blood pressure, and those in turn can raise the risk of heart disease.
People who drink more coffee also tend to smoke, drink more alcohol, eat more red meat and exercise less than non-coffee-drinkers -- all factors that affect one's health. Once NIH researchers took those things into account, a clear pattern emerged: Each cup of coffee per day increased the chances of living longer.
A Mayo review study also has revealed favorable information about coffee and heart disease, Hensrud said.
"Coffee will raise blood pressure acutely with short-term consumption. But, over time, a tolerance develops. ...
"Long term there doesn't seem to be a significant increase in blood pressure or a risk of developing hypertension from coffee."
Coffee has not been shown to be related to serious diseases, such as heart disease, cancer and other conditions, he said.
The NIH study does not prove that coffee makes people live longer, only that the two seem related. Like many studies on diet and health, this one is based strictly on observing people's habits and resulting health.
"It doesn't prove cause and effect," Hensrud said. "But it is consistent with other studies on the health benefits of coffee. There's a lot of data on health benefits that makes it plausible that the reduced risk is due to coffee consumption."
Because the NIH study involved so many people, more than a decade of follow-up and enough deaths to compare, "this is probably the best evidence we have" and are likely to get, said Dr. Frank Hu of the Harvard School of Public Health. He had no role in this study but helped lead a previous one that also found coffee beneficial.
Even a single cup a day seemed to lower risk a little: 6 percent in men and 5 percent in women. The strongest effect was in women who had four or five cups a day -- a 16 percent lower risk of death.
None of these are big numbers, though, and Freedman can't say how much extra life coffee might buy.
"I really can't calculate that," especially because smoking is a key factor that affects longevity at every age, he said.
In the new study, coffee drinkers were less likely to die from heart or respiratory disease, stroke, diabetes, injuries, accidents or infections. No effect was seen on cancer death risk, though.
Hu recommended limiting the use of sugar and cream, as those extra calories and fat could negate any benefits from coffee.
Filtered, rather than boiled, coffee is healthier, Hu said, since filtering removes compounds that raise LDL, the bad cholesterol.
Coffee has also been shown to have qualities that actually protect the body from disease, Hensrud said. "Coffee contributes more antioxidants to the diet than any other food or drink that people consume."
Antioxidants in general have been linked to a number of potential health benefits, including protection against heart disease and cancer, according to Phys.org, a science and medicine website.
Studies show coffee is associated with reduced risk of Type II diabetes, usually diagnosed later in life among men and women, Hensrud said, and may improve asthma symptoms.
"There is evidence of reduced risk of liver disease and liver cancer," he said, "and of reduced risk of Parkinson's disease."
Coffee has also been shown to positively affect mood and depression, as well as reduce the risk of suicide, he said. And "there's evidence to show coffee has a beneficial effect on cognition and thinking."
A few studies have linked coffee with a decreased risk of Alzheimer's disease, he said, "although the evidence is not strong; only a couple studies have shown this."
Coffee in large amounts can cause irritability, problems with sleeplessness and benign heart palpitations, he said. "It can make heartburn worse. In men, in particular, it can increase urinary symptoms.
"Also, if you drink it during the week and then not drink it on the weekend, you can have withdrawal headaches, because caffeine is mildly addictive."
Kelly Doda, an associate accountant at Brady Martz and Associates firm in Grand Forks, said she enjoys a break for a specialty coffee at the Urban Stampede "when I need to get away from the office and clear my head."
Coffee "keeps me going during tax season," she said, but it's not always a benefit.
"Sometimes, caffeine gets to me. When I drink coffee too late at night, say past 6 or 7 (p.m.), I can't go to sleep."
Sarah Sand, who owns the Coffee Company in Grand Forks, called the new NIH findings "very positive."
"There's a lot of studies in the last three or four years" that point to the benefits of coffee consumption, she said, including one that showed coffee could lower blood pressure.
"Research is finally shining light on the plus sides of coffee," she said. "It's awesome for the business. It's very encouraging when something shows your product is good."
People should take the NIH study as a good sign, Hensrud said.
"I wouldn't necessarily recommend people take up drinking coffee if they don't like it but, if they do, and they don't have negative side effects, there's no reason to cut down."