For example, feeling tired did not necessarily match consumption of a lower level of caffeine. Even participants in the first group reported symptoms, even though they had the same amount of caffeine in their coffee throughout the trial. The participants did not know the topic of the research. A segment of the participants was evaluated during a period of gradual caffeine withdrawal. These features helped to minimize problems with bias in the study design.
Consumers regularly choose to consume caffeine-containing foods and beverages.
Many report feeling uncomfortable or complain of headaches, nausea, fatigue, and muscle aches when they suddenly stop consuming these foods or beverages. Yet, these symptoms have not been documented in a scientific way. The researchers point out that it appears that many more people report a history of withdrawal symptoms than show them when evaluated under blind conditions. This study was supported by the North American Branch of the International Life Sciences Institute. Doctors Peter B. Dews, Charles P. O'Brien, Gary L Curtis and Kathryn J. Hanford were responsible for the conduct of the study.