Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: TUESDAY, September 13, 1994 TAG: 9409140002
SECTION: EXTRA PAGE: 6 EDITION: NEW RIVER VALLEY
SOURCE: By BOB CONDOR CHICAGO TRIBUNE
DATELINE: LENGTH: Medium
Forget that now. There are enough flavored coffees, lattes, au laits, mochas, espressos, cappuccinos and decaffeinated varieties to make your head swirl like cream in the cup.
It follows that research on the effects of coffee's primary chemical substance, caffeine, has also expanded - and caused some confusion. The lesson in the findings points toward moderation for most of us, abstinence for select groups. Here are a few sips of the latest research and information:
nA new study from Duke University Medical Center suggests caffeine will intensify stressful situations. Among men and women studied in different clerical and research jobs, there was an average 37 percent increase in adrenaline among the subjects consuming caffeine at the rate of two to three cups in a four-hour morning period.
When adrenaline rises - which it will do naturally when we face a threatening encounter - it also increases blood pressure, heart rate, muscle tension and perspiration. Coffee appears to heighten the length of the adrenaline rush, said Dr. James Lane, an assistant research professor of behavioral medicine at Duke.
``Caffeine helps you keep alert,'' he explained, and ``you can stay on a simple clerical task longer. But you can pay the price by drinking too much. For one thing, it shows a negative impact on performing complex tasks.''
The Duke study may make you rethink drinking your normal amounts of coffee on stressful or exciting days. Your natural adrenaline boost should be enough.
There's more to coffee than caffeine, and there's more to caffeine than coffee. ``Coffee has hundreds of chemicals, most of which have never been studied,'' Lane said.
There has been some research about polyphenols, found in coffee and especially tea. These substances can interfere with your body's absorption of calcium and iron. Although studies show a large amount must be consumed for serious deficiencies, it is recommended that you not take such supplements with a caffeinated drink.
Other findings report that decaffeinated coffee may cause an increase in blood cholesterol. Though it's not conclusive, the early reasoning is that decaf has more robusta beans, which appear to contain cholesterol-raising compounds.
There have been conflicting studies about the effects on caffeine on pregnancies. The prevailing research is a study published in the Journal of the American Medical Association last December that reported that women who had 1.5 to 3 cups of coffee a day doubled their chance of miscarriage.
Other sources of caffeine (tea, soft drinks, chocolate) may be less harmful, said Dr. Brenda Eskenazi of the University of California at Berkeley in an accompanying editorial. She said there may be certain chemicals released during the roasting of coffee beans that may cause pregnancy problems.
There is no conclusive research linking caffeine and coronary artery disease, though medical experts still caution anyone with hypertension or irregular heartbeats to consult their physicians about caffeine in their diets.
by CNB