The morning cup of coffee has an exhilaration about it which the cheering influence of the afternoon or evening cup of tea cannot be expected to reproduce: OLIVER WENDELL HOLMES, SR., AUTHOR
That exhilaration comes at least in part from the caffeine in the coffee, and caffeine is a mild diuretic. (A diuretic is a drug that promotes water loss.) So, you can’t count on coffee to replace the water you lose.
Perhaps because of the caffeine and the exhilaration it produces, there is a sense that coffee is somehow bad for you and that tea is somehow good for you. This is a very old belief; researchers have been trying to pin down the truth for hundreds of years. The earliest controlled trial I have come across was actually conducted in 18thcentury Sweden. A pair of identical twins had been sentenced to death for murder. King Gustavo III thought that rather than execute these twins, he would put them to work in service to science. He spared the gallows-bound twins in return for their participation in a controlled trial of coffee drinking versus tea drinking. One twin had to drink three large bowls of tea every day, and his brother had to drink the same amount of coffee. Both outlived the curious king. But the tea drinker died first, at the ripe old age of 83. His coffee-consuming brother joined him in the graveyard just a couple of months later. I’m not sure that counts as a coffee victory.
But science has continued to consider this question. Here’s what we know: coffee increases blood pressure in those who drink it occasionally, although this doesn’t appear to happen in habitual coffee drinkers. Coffee has been linked to elevated LDL cholesterol and other components that increase heart disease, but there is no evidence that coffee itself increases heart disease, despite many studies. Researchers have tried, without much success, I must add, to link coffee to all kinds of awful health outcomes in addition to heart disease: miscarriages and cancer, mostly. So far none of these connections have been confirmed.
It’s thought that much of the apparent guilt of coffee is by association due to lifestyle factors that often accompany coffee drinking, such as smoking. So, for now, coffee has a pretty clean bill of health. Bottom line: drink coffee if you enjoy it, but don’t count it as a beverage when you are trying to determine whether or not you are getting enough to drink.
