Do we blame the goat, or do we praise him? That is the question. I’m talking about the jittery goat, the one that, according to legend, belonged to Kaldi, the Yemeni goat herder. One day, some 1,200 years ago, Kaldi found his goat in a highly agitated state, darting back and forth, keeping everyone awake with frantic bleating. What could have caused this strange behavior? Kaldi wondered.
The inquisitive shepherd decided to follow the animal, and he soon found the root of the problem. Well, actually, the root wasn’t the problem; the trouble was the bush that grew from the root. It seems the goat had become bewitched after feasting on the bush’s strange, violet-colored berries. This was too much for Kaldi to handle, so he sought help from his religious leader, the Imam. Apparently, the sage had a scientific spirit, and made a brew of the berries. When he sampled the concoction, his heart began to race, and he suddenly felt very alert. The Imam had discovered the effects of caffeine! He named the beverage “Kahveh,” meaning “invigorating,” and we have been partaking of various versions of it ever since.
Today caffeine is the most widely used drug in the world, as about 80 percent of adults in Western societies consume it in coffee, tea, or soft drinks. Of course, when we drink coffee, we don’t consume only caffeine. There are hundreds of other compounds found in the bean, and more form as a result of the roasting process. It’s a good bet that at least some of these have an effect on our health. But what kind of effect?
First, let’s raise a somewhat disturbing point. If coffee were a synthetic substance, it would probably not be allowed on the market! That’s because it contains at least nineteen compounds that have been shown to cause cancer in test animals. Indeed, the natural carcinogens we ingest in coffee far outweigh the synthetic pesticide residues in our diet that frighten people so much. Yet we have no evidence at all that drinking coffee can cause cancer. An epidemiological study has even shown that coffee drinkers have a reduced risk of pancreatic cancer. Other studies have linked coffee with protection from liver and colon cancer. Why are we unaffected by the carcinogens in coffee? It is because they are not present in amounts anywhere near those that can trigger cancer in animals, and because coffee also contains a variety of antioxidants with anti-cancer effects.
So, no worry about cancer. What about heart disease? Well, two compounds in coffee, cafestol and kahweol, found in the oil droplets released from coffee beans by the brewing process, can stimulate the liver to make cholesterol. The problem, though, only arises with Scandinavian, Turkish, Greek, or “French press” coffees because the liberated oils stay in the coffee. Filter paper retains the oil droplets, which explains why filtered coffee does not elevate cholesterol. But even unfiltered coffee only becomes a problem at high doses. It takes about five cups a day to raise blood cholesterol by 10 mg/dL, the smallest change that can be reliably measured. Of course, there are people who drink that much, or more. Finnish men and women who regularly drink seven to nine cups of boiled coffee a day do have higher cholesterol levels. Espresso also contains cafestol and kahweol, but is consumed in such small volumes that the effect is insignificant.
Perhaps the most meaningful study to explore the link between coffee and heart disease was undertaken by the Harvard School of Public Health. No association was found between coffee intake and heart disease or stroke in over 45,000 health professionals who were followed for several years, even when more than four cups a day were consumed. This is comforting in light of a Greek study that showed that just one cup of coffee can temporarily make blood vessels more rigid. An interesting observation, but it’s apparently of no consequence.
In spite of some scares, no significant scientific evidence links coffee consumption to high blood pressure, osteoporosis, birth defects, or fibrocystic breast disease. More than three cups a day, though, may increase the risk of rheumatoid arthritis. There is no question that caffeine can increase urinary frequency, and men with prostate problems should take this into account. And, of course, nobody contests that caffeine is a stimulant. In fact, the Canadian army has shown that soldiers who chew caffeine-laced gum are more vigilant at night and have improved shooting accuracy. This sits well with the military, because the motto of modern warfare is that if you own the night, you win the war!
Believe it or not, coffee may even help in the wars against both Parkinson’s disease and type II diabetes. Several studies have shown a decreased risk of Parkinson’s with increased coffee consumption. This neurological disease is caused by a deficiency of a brain chemical called dopamine, possibly brought about by the overactivity of adenosine, another neurotransmitter. Adenosine is known to decrease dopamine levels. Caffeine inhibits the activity of adenosine, so a connection to Parkinson’s disease is plausible. Since adenosine can lull people to sleep, inhibiting its activity also accounts for caffeine’s stimulant effect. As far as type II diabetes goes, surveys have shown that four or five cups of coffee a day can reduce the risk by some 30 percent. Chlorogenic acid in coffee seems to keep sugar from being absorbed from the gut into the bloodstream.
Basically, then, there are no grounds to the allegations that coffee in reasonable amounts is harmful. It may even be helpful. After all, it seems that coffee is the main source of anti-oxidants in the North American diet! University of Scranton chemistry professor Joe Vinson determined the antioxidant content of more than 100 foods and beverages and found that, when frequency of consumption was taken into account, coffee provided the most antioxidants. A single cup (240 mL, or 8 ounces) contains about a gram of flavonoids, which are established antioxidants. This revelation, though, should not be taken as encouragement to drink more coffee. We don’t need the extra jitters. And if we get our antioxidants from fruits and vegetables, we get a good dose of vitamins, minerals, and fiber to boot. But it does seem that we don’t have to worry about drinking moderate amounts of coffee, except perhaps for the spent grounds. What do we do with them? Apparently, they are excellent for removing the smell of elephant urine. And you never know when that bit of information may come in handy.