Drink this in: Science has decided coffee is good for you

March 16, 2015

For centuries, coffee has caused a stir over health impacts, good or bad, with many people resigned to accept it as a guilty pleasure.

But in a full turnabout since the 1980s, science now extols its virtues as a generally healthful drink and kick-start for adults, with cautions for pregnant women and those with caffeine sensitivity and sleeping disorders.

The U.S. Department of Agriculture now agrees that coffee doesnít deserve its dark history and moderate consumption "can be incorporated into a healthy lifestyle."

The recently released 2015 Scientific Report of the Dietary Guidelines Advisory Committee, available online, includes 209 references to coffee, most of them favorable, particularly for those who donít add cream and sugar and limit daily consumption to three to five cups and no more than 400 milligrams of caffeine.

Itís the first time the committee has addressed the health effects of coffee and caffeine. Every five years, the USDA uses the report to establish science-based dietary guidelines.

"Strong and consistent evidence shows that consumption of coffee within the moderate range Ö is not associated with increased risk of major chronic diseases, such as cardiovascular disease and cancer and premature death in healthy adults," the report states in awarding coffee a "strong" grade.

"Itís long overdue for them," according to the author of "Uncommon Grounds: the History of Coffee and How it Transformed our World."

"You canít study people as you do rats," said Mark H. Pendergrast, a Harvard-educated independent scholar. "There have been many mistakes in confusing causality with correlation. But, in general, it seems that coffee now is getting a pretty clean bill of health."

As it turns out, the bean-like seeds inside the coffee plantís red and purple berries can reduce the risk of type 2 diabetes by 36 percent with protective effects against liver and endometrial cancers. Slight benefits were noted for other cancers the report didnít identify.

"Moreover, moderate evidence shows a protective association between coffee/caffeine intake and risk of Parkinsonís disease," the report states.

Overall, research found reductions in mortality among regular coffee drinkers. Studies not cited in the report showed benefits in preventing depression and Alzheimerís disease, among other neurodegenerative conditions.

The report even says decaffeinated coffee reduces the risk of diabetes and possibly lung cancer. While some advantages are attributable to caffeine, the 1,000 constituent compounds in coffee, including many healthful antioxidants known as polyphenols, may explain the positive health outcomes.

"Strong evidence supports a protective effect of moderate coffee consumption on chronic disease risk in healthy adults, but its association among those with existing diseases has been less studied," the report states. "Given that a substantial number of people suffer from these chronic diseases, the role of coffee in preventing other health outcomes in such groups remains understudied."

Coffee with its devilish color and bitter, acidic taste has held ground as one of the most popular beverages over the centuries, despite concerns and bad publicity about its effect on health. Several decades ago, it wrongly was blamed for pancreatic cancer, breast lumps, birth defects and heart disease.

It has long been condemned as an addictive drug that energizes some people and makes others jittery.

Thatís why Pendergrast opens his book with these words: "Throughout coffeeís history, critics have accused the drink of causing horrendous health problems, while those who love the brew have espoused its almost miraculous curative powers. This extreme devotion and condemnation continues today."

Coffeehouses throughout Europe became popular centuries ago with the preference, noted by a 17th-century writer, for coffee as a more "wakeful and civil drink" instead of beer each morning, earning coffee credit for bringing sobriety to England. Gustav III, the king of Sweden prior to his assassination in 1792, considered coffee a poisonous detriment to public health. He tested this idea by requiring one criminal twin to consume three daily pots of coffee and the other to drink three pots of tea. Both outlived officials monitoring the experiment and the assassinated king. The tea drinker died first at 83.

Grain moguls C.W. Post and the Kellogg brothers developed grain-based drinks with marketing campaigns warning that "coffee drunkards" faced multiple health effects including heart disease.

Such claims persisted until the 1980s, when "coffee was associated with over 100 diseases and disorders and, though subsequent studies threw every negative finding into question, the implanted fears led more consumers to decaffeinated alternatives or away from coffee completely," the Pendergrast book states.

On its website, the Mayo Clinic also says coffee studies failed to differentiate between heavy coffee consumption and habits often associated with coffee drinking, including smoking and physical inactivity.

It says coffee actually improves cognitive function and lowers the risk of depression; Pendergrast adds that coffee drinkers are less likely to commit suicide. "Thereís been a cultural shift," he said, "and you are right to focus on it. Itís a big deal."

But the battle continues. The Royal Society of Chemistry, an international group of chemical scientists based in the U.K., says two of the 1,000 compounds in coffee are carcinogens whose levels depend on what coffee beans are used and how they are roasted. The darker it is the better. But coffee has yet to be linked with cancer.

High consumption of unfiltered coffee (boiled or espresso) also has been associated with mild elevations in cholesterol levels, the Mayo Clinic states. Other studies found that two or more cups of coffee a day can increase the risk of heart disease in people with a specific ó and fairly common ó genetic mutation that slows the breakdown of caffeine in the body. "So, how quickly you metabolize coffee may affect your health risk," the clinic says.

The committee report also says "individuals who do not consume caffeinated coffee should not start to consume it for health benefits alone." Pendergrast says the government is reluctant to recommend anything thatís addictive.

But the chief concern isnít the coffee but such additives as cream, milk and sugars. "Care should be taken to minimize these caloric additions," the report says.

And while the artificial sweetener aspartame is considered safe, the report notes some uncertainty "about increased risk of hematopoietic (blood) cancer in men, indicating, again, a need for more research."

Pendergrastís book says humans tend to demonize or glorify things upon which they depend. For that reason, he expects arguments between those who consider coffee to be a "black, thick, nasty, bitter, stinking, nauseous puddle water" (as a petition of 17-century English women complained) and those who regard it as a "beverage of the friends of God" (to quote a 16th-century Arabic poet) to continue into the indefinite future.



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