The Patient Was…

Coffee!

It’s been called the “Nectar of the Gods, from Greek mythology.  Of course, the gods and goddesses could not have started their days on Mount Olympus with the brew since coffee probably wasn’t developed until about the 14^th century.  Of note, coffee was also once called Satan’s Drink, based on an outdated socio- religious notion, until Pope Clement VIII fortunately blessed it a few hundred years ago.

The overwhelming popularity of coffee is astounding. About 2.25 billion cups of coffee are consumed worldwide each day, with the U. S. contributing about 400 million of that total. Even in Asia, a region usually associated with tea, coffee consumption is high and rapidly growing. I’ve seen it myself in China and Japan; coffee shops abound.

Personally, I love coffee. I’ll have it any way it’s prepared: drip, pour over, pods, French Press, boiled, etc. Any way you make it, I’ll drink it.

So, what does this have to do with health?

Coffee’s stature in relation to health is a complicated and changing one.

For years, the majority of expert opinion on coffee in relation to health was basically negative. Recognized easily as a stimulant, coffee was associated with stress, anxiety, sleeplessness, high blood pressure, bowel disorders,  cancer, and cardiac arrythmias (disorders of the heart rhythm) among other things.

Part of the problem was that coffee doesn’t exist in the world as an isolated entity. People who drink coffee imbibe and do a lot of other things. A prime example is the linkage of coffee with heart disease and cancer.

When an observational study  —  one that was not a randomized, controlled trial, but rather just looked at compiled statistics   —  found that coffee drinkers had more heart disease and lung cancer, the beverage was condemned for those findings. Later, when wiser researchers looked at the data, they realized that many coffee drinkers also smoked; those cups of coffee were almost always accompanied by one or more cigarettes. When the data on coffee drinkers who did not smoke were analyzed, the association of coffee with heart disease and lung disease simply disappeared.

Guilt by association!

The “guilt by association” problem in much research is a real problem. It’s called confounding. It occurs when something unrelated to what you are studying affects the results of your study. The linkage of smoking and coffee drinking is often cited as a prime example of confounding: smoking caused the apparent increase in heart and lung disease in coffee drinkers, because smoking and coffee drinking were often present together. But the coffee was innocent; smoking was the real culprit.

A classic example of confounding was a study that led to the conclusion  —  erroneous in my view  —  that physical activity conferred longevity in humans. The study, published in 1952, reported that London bus conductors, who ran up and down the double-decker bus stairs all day, had lower rates of heart disease and longer lives than did the more sedentary bus drivers. The conclusion was that the physical activity of the conductors was responsible for the benefits. Later, the study was corrected when it was realized that the conductors had lower blood pressure, lower cholesterol and lower body weight than the drivers, even before they started their respective jobs. Those factors, not the activity of the job, were the cause of the better health outcomes. (More on this in my book, The Exercise Myth).

To return to coffee, something I’m always eager to do, recent views on the health consequences of coffee drinking have changed considerably. Coffee has been absolved of many of its criticisms and has, in fact, been credited with positive health benefits.

A key question, assuming coffee is good for you, is just how much coffee is good for you. After all, anything in excess, even water, can have deleterious effects. According to current thinking, 3 to 5 cups per day seems to be the sweetest spot. Fewer cups are all right, but may be less beneficial in terms of health. More may be dangerous although there is no good correlation between number of cups and outcomes.

Another question is whether decaffeinated coffee has the same health benefits as caffeinated coffee. The answer is a bit of a hedge, because there are less data about decaffeinated coffee than there are about caffeinated coffee. In general, the benefits overall seem to be similar between caffeinated and decaffeinated varieties of coffee, except in the area of extra energy and mental alertness. Here, the effects of caffeine are unique.

If decaffeinated and caffeinated coffee in general have similar benefits, what does this say about caffeine? What it says is that coffee is not just a source of caffeine. In fact, coffee contains hundreds of different chemical compounds, including antioxidants, that contribute to its effects. Caffeine may be a major component of regular coffee, but it is responsible for only a limited number of coffee’s effects. Caffeine itself, in isolation, can be dangerous; the amount in so-called energy drinks is much higher than in coffee and excess caffeine intake can cause real problems, including acute elevations in blood pressure and the onset of serious heart rhythm disturbances (arrythmias). Cases of sudden cardiac death due to caffeine-induced arrythmias are well known.

The effects of coffee on blood pressure follow an interesting pattern. In a person who regularly drinks coffee, the effects on blood pressure are either nil or actually a lowering of blood pressure over time. In a coffee-naïve individual, however, coffee will raise blood pressure.  

The response of blood cholesterol to coffee is also interesting. A compound in coffee tends to slightly raise cholesterol levels; slightly is the operative word.  Certain brewing methods may affect this but filtering the coffee through plain coffee filter paper removes the cholesterol-raising compound and eliminates even that small effect of coffee on cholesterol. Instant coffee, by the way, does not affect cholesterol levels.

Because of its stimulating effects, caffeine was always thought to cause irregularities in the rhythm of the heartbeat. Large doses of caffeine, not like those normally contained in coffee, can do that. But coffee itself has now been shown to decrease heart rhythm abnormalities, even the well-known arrythmia known as atrial fibrillation, (or A Fib). I confess that I was among the large majority of physicians who used to advise vulnerable patients to avoid coffee in order to reduce the likelihood of A Fib. Now, guidelines from the American College of Cardiology and the American Heart Association reject that advice.

It’s important to remember that not everybody reacts the same way to anything. There are certainly individuals who are sensitive to the effects of coffee and respond differently from the majority of people whose reactions to coffee are the basis for the latest recommendations. If you are one such individual, then avoidance of coffee makes sense. Your physician is the best guide, as always.

Since the latest data show that coffee has an overall favorable profile in matters of health in most people, long-standing concerns about its deleterious effects seem to be resolved. If you respond differently, then coffee is not for you. But for most of us, happily including me, coffee is, once again, the Nectar of the Gods.