POSTED: 1:30 a.m. HST, Oct 5, 2010
Marketing "energy" is big business. Many people are choosing "energy drinks" spiked with caffeine and other supposed energizers. Sadly, many energy drinks and pre-workout boosters provide little information about the amounts of caffeine and other ingredients because they are a proprietary blend.
As an alternative to consuming beverages with unknown levels of possibly harmful ingredients, why not have a cup of coffee? And, no, we are not subsidized by the coffee industry. The common 8-ounce cup of coffee provides about 100 milligrams of caffeine. The amount of caffeine, however, depends on the type of coffee and the strength of the brew. For example, just 1 fluid ounce of espresso can provide 65 mg of caffeine.
In attempts to find health problems caused by coffee, thousands of studies have been conducted. Many of these were looking for health risks and found none. Other studies actually found health benefits. Most research on coffee supports the concept that if coffee was recently discovered in a faraway location, coffee would be the hottest selling herbal beverage in the health food market.
Question: What potential health benefits are linked to coffee drinking?
Answer: Epidemiological studies that look for positive and negative associations with health have identified some encouraging links to specific health benefits. Although these results can't prove cause and effect, they indicate those who drink coffee have a decreased risk for conditions like type 2 diabetes, Parkinson's disease, liver disease, Alzheimer's disease and colorectal cancer. Overall, the more recent well-designed studies have found no association between coffee consumption and cancers in general. There also is evidence that coffee consumption helps to prevent tooth decay.
Q: Why would coffee be beneficial to health?
A: Coffee contains many things besides caffeine. Two cups of strong coffee provide as much potassium as a medium banana and about 40 percent of the daily need for the vitamin pantothenic acid. In addition to these nutrients, coffee also contains compounds with names like chlorogenic acid, cafestol and kahweol. Finding potential positive and negative aspects of these compounds is an ongoing area of research. Chlorogenic acid may be the key component that contributes to the reduced risk of type 2 diabetes. Cafestol and kahweol, present mainly in unfiltered coffee, are thought to contribute to a small but significant increase in blood cholesterol levels, but also may help to prevent cancer.
Q: Is there a downside to drinking too much coffee?
A: Everything in life seems to have its diminishing point of return. A report from Health Canada concluded that caffeine intake up to 400 mg per day is not associated with adverse health effects in healthy adults. However, caffeine is a drug. And, like most drugs, individual sensitivity to caffeine can vary. For some, caffeine boosts blood pressure. Too much caffeine too close to bedtime can, of course, adversely affect sleep. The absorption of iron from foods can be decreased when coffee is consumed with the food. It is commonly recommended that women who are pregnant, lactating, or planning pregnancy do not consume more than 300 mg of caffeine per day (about three 8-ounce cups of coffee). There is conflicting evidence that excess coffee consumption (more than four cups per day) during pregnancy can increase the risk of childhood acute lymphoid leukemia.
Joannie Dobbs, Ph.D., C.N.S., and Alan Titchenal, Ph.D., C.N.S., are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii-Manoa. Dobbs also works with University Health Services.