That cup of coffee you grab every morning after staying up the night before may do more than perk you up. It actually has positive effects on learning and decision-making, said Dr Ooi Yau Wei. "Individuals who are habitual consumers of coffee and tea have been shown to perform better on various tests of cognitive performance such as reaction time and visual-spatial skills," said the cardiologist at Mount Elizabeth Novena Hospital. Found naturally in tea, coffee, cocoa products, or added to beverages such as energy drinks and carbonated beverages, caffeine works by affecting our central nervous system - more specifically, adenosine.
It is a hormone that is responsible for slowing the nervous system and relaxing the body, said Ms Natalie Goh, chief dietitian at Mount Elizabeth Novena Hospital. "When we consume a drink or food containing caffeine, it blocks the effects of adenosine, resulting in greater alertness, mental energy and concentration," she said.
Other than giving that much-needed pick-me-up, caffeine also has been shown to influence cognition and mood. In small and moderate doses, it improves vigilance and reaction time in those who are well rested, said Dr Ooi. Due to its pain-alleviating symptoms, the stimulant can also be found in common painkillers such as paracetamol, ibuprofen and aspirin. "It is frequently used alone or in combination with other headache treatment medications.
"However, regular caffeine consumption can also lead to chronic migraine and analgesic rebound headache," said Dr Ooi. Analgesic rebound headaches are caused by overusing headache medication or painkillers. While low to moderate coffee consumption - up to three cups a day - has been shown to protect against heart attacks, it is not all rosy.
Ms Goh said it can cause interrupted sleep as well, depending on the amount and time of consumption. Too much caffeine can also cause a rapid heart rate, elevating blood pressure in some individuals, especially those sensitive to the effects of caffeine, she said. It is possible to develop mild physical dependence with regular and excessive consumption, added Ms Goh.
"For example, if a person has a habit of drinking five to six cups of coffee a day and tries to cut down drastically to one cup or none, he may experience the symptoms of initial withdrawal, such as headache, difficulty concentrating, irritability and fatigue. "The effect is not as harmful as other forms of addiction, like drug addiction," she said. For those with underlying heart disease, Dr Ooi said more than three cups of caffeine may trigger heart artery problems and heart rhythm irregularities. "Thus, patients at risk of heart problems should avoid drinking large quantities of caffeine," he said.
Despite the risks, research suggests that the pros outweigh the cons, provided you do not have any existing conditions that can be worsened by caffeine. "Perhaps your daily cup has more benefits than you thought," he added.
This article was first published at The New Paper.