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United States Department of Agriculture

Agricultural Research Service

Coffee -- A functional food with health benefits
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By Eric Uthus


The Institute of Medicine defines functional foods as "those foods that encompass potentially healthful products including any modified food or ingredient that may provide a health benefit beyond the traditional nutrients it contains."

For many, including myself, coffee is a functional food -- not in the sense of the medical definition, but in the sense that we don't function as well without morning coffee.

Whether drinking coffee is harmful has been debated for a long time. For example, in 1674, women (who weren't allowed in London coffeehouses), petitioned to have coffee banned, claiming it made their spouses impotent (This can't be true, as I have three beautiful daughters.). More recently, some studies that blamed coffee for a myriad of problems were found to be flawed, as they neglected to factor in cigarette smoking.

Other studies have indicated that coffee, in moderation, is at most, not harmful. More recently, however, studies have emerged showing that coffee may have numerous health benefits. For example, in several large-scale studies conducted by scientists in the United States and abroad, it was found that the risk for type 2 diabetes was lower among regular coffee drinkers when compared with those who didn't drink coffee.

At present, there is little evidence that coffee consumption increases the risk of cancer. On the contrary, colon cancer appears to be reduced in people who drink four or more cups of coffee each day.

Also:

  • In women, a lifetime of coffee consumption is associated with better performance on certain cognitive tests.
  • Another study showed that coffee consumption is associated with slower cognitive decline in elderly men.
  • Drinking more than 2 cups of coffee a day was correlated to a reduced risk of liver damage in people at high risk for liver disease (heavy drinkers, people with hepatitis or those with some iron overload disorders).
  • Coffee has been shown to improve performance in long-duration physical activities.
  • Finally, several studies have shown that risk of Parkinson's disease is reduced in coffee drinkers.

Why does coffee seem to have such a wide range of effects? Coffee contains "traditional" nutrients such as chromium, magnesium and niacin. Consumption can furnish up to 8 percent of the daily chromium intake and can be a substantial source of magnesium and niacin. Also, an 8-ounce cup of instant coffee prepared with water contains about 72 milligrams of potassiumabout one-fifth the amount found in a small banana.

However, more and more researchers believe that the wide range of beneficial effect is due to evidence showing that coffee fits the bill as a functional food. In other words, coffee, like tea, contains compounds that are plant chemicals as well as "traditional" nutrients that impart a health benefit beyond those provided by these long-established nutrients.

Ingredients typically associated with functional foods that are contained in coffee include various flavonoids, caffeic acid and ferrulic acids (antioxidants).

Coffee also is the main source of the trace element boron for most adult Americans who consume just less than 1 milligram of boron each day, according to a study led by Curtiss Hunt, a biologist here at the Grand Forks Human Nutrition Research Center. He found that an 8-ounce cup of instant coffee contains about 57 micrograms of boron.

Boron long has been considered an essential nutrient for plants, and Dr. Hunt has found in a study with rats that boron in the diet reduced the amount of insulin in the blood needed to maintain the proper amount of glucose.

Even with coffee's health benefits, there still are potential health risks. Coffee consumption is associated with some cardiovascular effects such as increased blood pressure, heart rate and irregular heartbeat. People with hypertension, children and the elderly, may be more vulnerable to the adverse effects of the main ingredient, caffeine.

Thus, as with most foods, consumption in moderation is best. So, please pass the coffee and, while you are at it, how about some dark chocolate!


Last Modified: 11/1/2006