How Caffeine Works continued...
"There's no question," says Roland R. Griffiths, PhD, professor in the departments of psychiatry and neuroscience at Johns Hopkins University School of Medicine in Baltimore and a veteran researcher in the area. Caffeine is addictive for some people, he says. "Caffeine does produce dependence, and caffeine withdrawal is a real syndrome."
But George Koob, PhD, professor of the Committee on the Neurobiology of Addictive Disorders at The Scripps Research Institute, San Diego, disagrees. "While it is possible to be addicted, most people are not," he says. "I think most of my colleagues would agree."
The Benefits of Caffeine
Caffeine can improve memory, decrease fatigue, improve your mental functioning, study after study suggests.
It can improve your short-term memory and speed up your reaction times, according to a study presented in 2005 at the Radiological Society of North America.
Moderate coffee consumption -- defined as three or four cups a day, providing 300 or 400 milligrams of caffeine -- carries "little evidence of health risks and some evidence of health benefits," conclude researchers from the Linus Pauling Institute at Oregon State University in Corvalis, writing in Critical Reviews in Food Science and Nutrition in March 2006.
Coffee drinking, the researchers say, may help prevent type 2 , , and liver disease, including . And it doesn't appear to significantly increase risk or . But, they warn, those with , as well as children, teens, and the elderly, may be more vulnerable to caffeine's adverse effects.
The Downsides of Caffeine
Caffeine does boost blood pressure, Lane and others have found. Although the rise is temporary, Lane questions whether it's good for you when it occurs over and over. After much research, he has concluded that repeated elevations in blood pressure and increases in your reactions to daily stress that occur with caffeine intake could boost the risk of heart disease. He worries, too, about the boost in blood glucose levels that accompanies caffeine intake.
Daily soft drink consumption may lower bone mineral density in women but not men, researchers from Tufts University reported in the October 2006 issue of the American Journal of Clinical Nutrition.