2. Myth: Caffeine is unhealthy
Truth: Moderate amounts of caffeine–about 300 milligrams, roughly three cups of coffee–apparently cause no harm in most healthy adults. Although some people are more sensitive to its effects, including older people and those with high blood pressure. Here are the facts by condition.
At high levels (more than 744 milligrams per day, around seven or eight cups of coffee), caffeine may increase calcium and magnesium loss in urine. But recent studies suggest it does not increase your risk for bone loss, especially if you get enough calcium. You can offset the calcium lost from drinking one cup of coffee by adding just two tablespoons of milk. However, research does show some links between caffeine and hip fracture risk in older adults. Older adults may be more sensitive to the effects of caffeine on calcium metabolism. If you’re an older woman, discuss with your doctor whether you should limit your daily caffeine intake to 300 milligrams or less.
According to the Harvard Nurses’ Health Study, caffeine consumption does not increase the risk of cardiovascular disease and does not raise cholesterol levels or cause irregular heartbeat. A slight, temporary rise in heart rate and blood pressure is common in those who are sensitive to caffeine–but the rise is minimal and comparative to normal activity like walking up stairs. That said, ff you have high blood pressure talk to your doctor about caffeine intake as some people may be more sensitive to its effects. Also, more research is needed to tell whether caffeine increases the risk for stroke in people with high blood pressure.
According to The New York Times, scientists conducting an international review of 66 studies 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.” And a study of 59,000 women in Sweden (the country with the highest coffee consumption per capita in the world) found no connection between caffeine consumption and breast cancer.