It is believed that these compounds offset the effect of another ingredient of coffee, caffeine. Caffeine is a well-known stimulant that can set the heart racing, and prevent sleep. They believe the compounds also have potential for treating epilepsy, hyperactivity and sleep problems. The research could lead to new treatments for insomnia Laboratory tests show chlorogenic acids act as antioxidants, mopping up destructive free radical molecules which contribute to heart disease. Some also appear to influence a chemical, adenosine, that controls the rate at which nerves transmit messages.
Caffeine causes the heart to pound by blocking the action of adenosine.
A lack of adenosine is also implicated in conditions such as supraventricular tachycardia, where the heart beats at a constant rate but much too fast. Adenosine also dilates arteries, allowing more blood to flow through. This may help prevent heart muscle being starved of blood, the cause of painful angina and heart attacks. US scientists have discovered that chlorogenic acid increases levels of adenosine by preventing its re-absorption by the body. Some of these chlorogenic acids appear to counteract the action of caffeine, and may be helpful in fighting diseases which feature low adenosine.