More than half of American adults drink coffee every day, and few foods cause as much divided loyalty as the coffee bean. From where you choose to purchase, from dark roasts to light, whole bean or ground, coffee remains a point of love and strong opinion at every turn.
Botanical evidence places the first wild coffee plants in Abyssinia, on the central plateaus of what is today Ethiopia. The fruit of these wild plants was eaten by nomadic herdsmen, who crushed it together with animal fat, then formed it into balls that they carried with them for snacks. One suspects the herdsmen found that, as a bonus, they were able to stay awake longer and were in a generally more cheerful mood.
The coffee plant made its way to what is now Yemen about 1,500 years ago, where it became a cultivated crop. From there the culture of coffee moved to Constantinople and eventually to Europe, no doubt in part through the extremely social Suleiman Aga (ambassador from the Ottoman Empire to the court of Louis XIV), who threw flamboyant coffee parties for the French nobility.
In the early 1700s, through a series of political and romantic intrigues, a stolen coffee plant made its way to the West Indies and from there to Central and South America. About 150 years later, coffee seed from Brazil was introduced in Kenya and Tanzania, several hundred miles south of coffee’s original home in Ethiopia.
Coffee is grown around the world in the Coffee Belt, the frost-free band between the Tropics of Cancer and Capricorn, and the best coffees are grown at the higher altitudes. The relatively cooler temperatures at the high altitudes slow the growth of the coffee fruit, and as a result produces a denser, harder bean, with more flavor.
Coffee offers few nutrients, but it does contain more than 1,000 naturally occurring chemicals, some of which are potentially healthful (and others potentially harmful) in ways not well understood.
Research indicates that coffee may reduce the risk of type 2 diabetes and stroke. Some studies suggest that coffee may also reduce the risk of certain cancers, including prostate cancer, although the findings are inconsistent. Research also suggests that coffee may help protect against Parkinson’s disease, depression, and cognitive decline. But most of these potential health benefits are based on observational studies, so they don’t prove cause and effect.
Coffee’s main claim to fame is caffeine. Caffeine is a psychoactive substance that stimulates the central nervous system. It improves reaction time, mental acuity, alertness, and mood, Caffeine wards off drowsiness and can help people wake up and feel better in the morning.
The amount of caffeine in any single serving of coffee depends on a number of factors, including the variety of coffee, where the beans were grown, the year the beans were grown, the type of roast, the fineness of the grind, the brewing method, the length of brewing, and the proportion of coffee to water.
The effects of caffeine vary from person to person. Most people can safely tolerate up to 400 milligrams a day, the amount of caffeine in four cups of freshly brewed coffee. Large amounts (more than 500 to 600 milligrams a day) may cause adverse effects such as insomnia, restlessness, nervousness, and trembling. Too much caffeine can temporarily boost heart rate and cause palpitations. Stopping caffeine suddenly may also cause temporary withdrawal symptoms like headache and irritability if people who drink a lot of coffee suddenly stop. Tapering consumption gradually over several days can help to prevent the symptoms of caffeine withdrawal.
Still, the U.S. Food and Drug Administration considers caffeine to be “Generally Recognized as Safe,” and most studies on long-term negative effects have been refuted by more recent research.
A note for pregnant women: The American College of Obstetricians and Gynecologists (ACOG) recommends that pregnant women limit caffeine to about 200 milligrams a day. There’s some evidence that daily intakes of more than 200 milligrams of caffeine may put a pregnancy at risk, possibly by decreasing blood flow to the fetus, though the findings have been inconsistent. Drip coffee brewed at home contains 80 to 135 milligrams per 8-ounce cup. A tall Starbucks coffee, which is 12 ounces, delivers about 260 milligrams. But caffeine content can vary widelydepending on who’s doing the brewing.
Types of Coffee
Find out the differences between types of roasted coffee and coffee beans.
A word about instant coffee and fair trade coffee
Instant coffee is usually made from lower quality robusta beans, but research suggests it may offer similar health benefits as high quality roasted coffee. Some studies have shown that drinking instant coffee may help manage blood sugar levels and cardiovascular health. However, more research is needed before it’s proven that any form of coffee confers health benefits.
Fair trade coffee is certified as having been produced to fair trade standards, which guarantee farmers a minimum price and links farmers directly to coffee importers.
How to choose the best coffee
It is important to buy coffee from a store that has a brisk turnover because beans should be as fresh as possible. When roasted coffee beans are exposed to air, their volatile aromatics start to dissipate, or oxidize, and the coffee begins to go stale. Coffee beans sold in vacuum-sealed bags or cans will stay fresh indefinitely as long as the container is closed. Once opened, the same rules about oxidation apply.
How to store coffee
For the longer shelf life, it’s best to buy unground coffee beans. And, especially for dark roasts, you should store them in the refrigerator or freezer. If you have the store grind the beans for you, then the ground coffee should definitely be stored in the freezer, in an airtight container.
Also see Decaf Coffee: A Healthy Choice?
Published February 29, 2016