As for roasting method, darker-roasted beans actually have less caffeine than those that are lighter, because heat from roasting removes the caffeine. The answer probably depends as much on what you consume in the coffee, or with it, as it does on the coffee itself. Despite years of speculation and research, scientists have not been able to link normal levels of caffeine intake to major chronic diseases like heart disease or cancer. The most common and well-defined effect of coffee stems from its role as a central nervous system stimulant. Within 30 to 60 minutes of drinking coffee, caffeine levels peak to produce alertness and heightened concentration.
Some research suggests a link between high caffeine levels and birth defects and miscarriages.
Pregnant women should consult their physicians about drinking coffee or other caffeinated beverages during pregnancy. People with high blood pressure or with an irregular heartbeat should also consult their doctor about caffeine, as it can worsen both conditions. For more information, contact your local Colorado State University Cooperative Extension office . Go to top of this page. Contact Cooperative Extension Web Manager .