Americans love their coffee. According to a market research study conducted by the National Coffee Association, 83 percent of adults in the United States say they drink coffee. If you're one of them, consider the effects of coffee consumption. While drinking coffee can provide important perks, it also has a few drawbacks.
Coffee can help you stay more alert if you spread its consumption throughout the day -- but moderation is the key, according to the Harvard Medical School. This means that most people can drink two to four 8-ounce cups of coffee a day without experiencing harmful effects. Drinking coffee may also help maintain mental health longer. A study investigating the relationship between coffee consumption and mental decline revealed that consuming no more than three cups of coffee daily helps reduce cognitive decline, according to an article published in "European Journal of Clinical Nutrition" in February 2007.
Coffee's an excellent source of dietary antioxidants, powerful substances that help protect your body from free radicals, unstable molecules that damage healthy cells. Antioxidants have been linked to decreased risk for developing cancer and heart disease. An article published by "Food Chemistry" in June 2009 noted that caffeic acid, a naturally occurring protective substance in coffee, is a very effective antioxidant.
Heart Disease Risk
Coffee's a complicated blend of compounds that may affect your cardiovascular system either positively or negatively. While antioxidant compounds in coffee provide positive protective effects, caffeine compounds may pose potential health problems. An article published in "Current Opinion in Clinical Nutrition and Metabolic Care" in November 2007 noted that a study examining the relationship between coffee and risk of myocardial infarction -- heart attack -- provided strong evidence that caffeine in unfiltered coffee increases the risk of coronary heart disease.
Additional Unfavorable Factors
Although most people can drink two to four cups of coffee a day without experiencing harmful effects, consuming excess caffeine can cause several problems. According to MedlinePlus, drinking too much coffee can cause dehydration, headaches and dizziness and can make you jittery and shaky. In addition, excess coffee consumption can make your heart beat faster or result in abnormal heart rhythms. It may also affect your ability to fall asleep and stay asleep.