Caffeine Myths You Might Still Believe
Through the years, the public has been blinded by misguided information about caffeine, and its most common source, coffee. In March, the Center for Science in the Public Interest published a comprehensive appraisal of scientific reports in its Nutrition Action Health Letter. Its findings and those of other research reports follow.
It was long thought that caffeinated beverages were diuretics, but studies reviewed last year found that people who consumed drinks with up to 550 milligrams of caffeine produced no more urine than when drinking fluids free of caffeine. Above 575 milligrams, the drug was a diuretic.
So even that Grande coffee, with 330 milligrams of caffeine, will not send you to a bathroom any sooner than 16 ounces of pure water. Drinks containing usual doses of caffeine are hydrating and, like water, contributing to the body’s daily water needs.
2. Heart Disease
Heart patients, especially those with high blood pressure, are often told to avoid caffeine, a known stimulant. But an analysis of 10 studies of more than 400,000 people found no increase in heart disease among daily coffee drinkers, whether their coffee came with caffeine or not.
Cardiologists at the University of California, San Francisco concluded,
Contrary to common belief, there is little evidence that coffee and/or caffeine in typical dosages increases the risk of heart attack, sudden death or abnormal heart rhythms.
In fact, among the 27,000 women that were followed for 15 years in the Iowa Women’s Health Study, those who drank one to three cups a day reduced their risk of cardiovascular disease by 24 percent, although this benefit diminished as the quantity of coffee rose.
Caffeine induces a small, temporary rise in blood pressure. But in a study of 155,000 nurses, women who drank coffee with or without caffeine for a decade were no more likely to develop hypertension than non-coffee drinkers. However, a higher risk of hypertension was found from drinking colas. A Johns Hopkins study that followed more than 1,000 men for 33 years found that coffee drinking played little overall role in the development of hypertension.
Panic swept this coffee-dependent nation in 1981 when a Harvard study tied the drink to a higher risk of pancreatic cancer. Coffee consumption temporarily plummeted, and the researchers later concluded that perhaps smoking, not coffee, was the culprit.
In an international review of 66 studies last year, scientists found coffee drinking had little if any effect on the risk of developing pancreatic or kidney cancer. In fact, another review suggested that compared with people who do not drink coffee, those who do have half the risk of developing liver cancer.
A study of 59,000 women in Sweden found no connection between coffee, tea or caffeine consumption and breast cancer.
5. Bone Loss
Though some observational studies have linked caffeinated beverages to bone loss and fractures, human physiological studies have found only a slight reduction in calcium absorption and no effect on calcium excretion, suggesting the observations may reflect a diminished intake of milk-based beverages among coffee and tea drinkers.
Dr. Robert Heaney of Creighton University says that caffeine’s negative effect on calcium can be offset by as little as one or two tablespoons of milk. He advised that coffee and tea drinkers who consume the currently recommended amount of calcium need not worry about caffeine’s effect on their bones.
6. Weight Loss
Here’s a bummer. Although caffeine speeds up metabolism, with 100 milligrams burning an extra 75 to 100 calories a day, no long-term benefit to weight control has been demonstrated.
In fact, in a study of more than 58,000 health professionals that were followed for 12 years, both men and women who increased their caffeine consumption gained more weight than those who didn’t. (Maybe too much creamer.)
So there are your six myths of caffeine. Did you still believe any of these? Let us know in the comments.