Coffee studies say ... it's cloudy

Democrat-Gazette illustration/CELIA STOREY
Little man over a cup of coffee for ActiveStyle secondary illustration, April 27, 2015. Cup is by Little Rock artist Ashley Morrison.
Democrat-Gazette illustration/CELIA STOREY Little man over a cup of coffee for ActiveStyle secondary illustration, April 27, 2015. Cup is by Little Rock artist Ashley Morrison.

Conventional wisdom on coffee has flip-flopped. Once considered an indulgence with potentially harmful health effects, coffee is now being talked about as a magical elixir that could save your life.

Could this be true? Lately every new study that confirms drinking coffee doesn't usually kill people is greeted with breathless reports.

The most recent round came in March after the journal Heart published "Coffee consumption and coronary artery calcium in young and middle-aged asymptomatic adults." This study found that people who drank three to five cups of coffee a day -- considered a "moderate" amount -- had cleaner arteries than those who did not drink coffee.

The study, which looked at 25,000 young to middle-aged men and women in Korea, did contain positive news about coffee, but some reports misinterpreted its conclusions.

The reality is that a growing body of research supports the idea that coffee, in reasonable amounts, might not be as bad for people as once thought. Brewed coffee, for instance, has been found to contain healthful antioxidants. In fact, the latest scientific report of the 2015 Dietary Guidelines Advisory Committee, the nation's top nutrition panel, weighed in on coffee (for the first time in the panel's history), saying that "strong evidence" shows it is "not associated with increased long-term health risks among healthy individuals."

The key words here are "healthy individuals." Due to its high caffeine content, brewed coffee can become a source of insomnia, irritability, acid reflux and other negative side effects for others, especially those with underlying conditions such as anxiety disorder or heart disease.

More importantly, there's still a lot of space that needs to be bridged to make the leap between coffee not being bad for you and coffee being the cause of better health.

Here's a look at the Heart study and other recent studies about coffee and what they do -- and do not -- say.

HEART DISEASE

Researchers found an association between drinking three to five cups of coffee and the amount of coronary artery calcium, an early warning sign of heart disease. Science does not have information to conclude there's a causal link.

Since it was an observational study the scientists weren't really able to control for other things, such as diet, exercise and environmental factors that could have affected the outcome. Also, the study's subjects didn't have any signs of cardiovascular disease, so it's unclear how coffee consumption might affect those who already have heart disease.

But as the study was written up on blogs and social media outlets in March, many began to think that the findings were even more amazing -- that the scientists had discovered that drinking coffee was better for your heart than, say, eating a plateful of broccoli. One story about coffee promised that "five a day keeps heart disease away."

Others declared that the study found that coffee "prevents clogged arteries" or "prevents heart attacks" even though the study did not go there.

LONG LIFE

A study published in the New England Journal of Medicine in 2012 found that older adults who drank caffeinated or decaffeinated coffee had a lower risk of death than those who did not drink coffee. But the study, which was conducted by the National Cancer Institute and the AARP, adjusted out factors such as alcohol consumption and smoking.

They found that the coffee drinkers were less likely to die from heart disease, respiratory issues and infections, but not from cancer. The researchers cautioned that "whether this was a causal or associational finding cannot be determined from our data."

DEPRESSION

Researchers at the Harvard School of Public Health who tracked 50,000 women found that those who drank four or more cups of coffee with caffeine were 20 percent less likely to develop depression, but the researchers said that they need to do more research before they can recommend that women should drink more coffee.

TYPE 2 DIABETES

A study published in 2006 in Diabetes Care that looked at 88,259 American women ages 26 to 46 years without a history of diabetes at the beginning found that the women's relative risk for diabetes was lower if they drank two to three cups a day and even lower if they drank four or more cups a day.

The results were similar for caffeinated and noncaffeinated coffee. But the researchers were confounded as to what might explain that effect other than saying that an ingredient of coffee other than caffeine seemed to be at play.

PARKINSON'S DISEASE

A study published in JAMA: The Journal of the American Medical Association in 2000 analyzed health data from 8,004 Japanese-American men (aged 45 to 68 years) who were enrolled in a Honolulu study. The researchers found that higher caffeine intake seems to be associated with a significantly lower incidence of Parkinson's and that that's independent of smoking. In this study researchers said their work suggests the effect may be due to caffeine rather than another nutrient in coffee.

ActiveStyle on 04/27/2015

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