Part 9 in my series of posts about products which can contribute to nutrient deficiencies –
Coffee, Tea, and Caffeine
Coffee and caffeine have been accused of contributing to many degenerative disorders, including heart disease and cancer; however, the effects of coffee or caffeine on these disorders remain inconclusive. A study from the University of California, San Diego, reported that it is not coffee but the habits associated with coffee drinking that predispose a woman to heart disease. Coffee drinkers are more likely than nondrinkers to consume more alcohol, dietary saturated fat, and cholesterol; they are more likely to smoke and not exercise regularly. In addition, smoking and exercise are “dose-related” to coffee consumption. That is, the more a woman smokes and the less she exercises, the greater her coffee consumption and her risk of developing heart disease. These associations between coffee consumption and heart disease behaviors hold true for both drinkers of caffeinated and decaffeinated coffee.
Unfortunately, the evidence is not clear-cut. Other studies have reported a significant association between coffee consumption and the risk of heart attack. Again, the more coffee a person consumed, the greater the risk. In addition, the chance of having a fatal heart attack rises steadily in men who drink three or more cups of coffee a day; however, the effects on women have not been adequately studied. Switching from regular to decaffeinated coffee might not be the answer, either, since both caffeinated and decaffeinated coffees have been implicated in heart disease risk.
How does coffee increase a person’s risk of heart disease? Caffeine in doses greater than five cups of coffee a day might increase total blood cholesterol and LDL-cholesterol levels, blood pressure, and heart arrhythmias – all factors that increase a person’s risk of developing heart disease. It is not well substantiated, however, whether this is caused by caffeine, one or more of the three hundred compounds in coffee, or related behaviors associated with coffee consumption. Drip-filtered coffee, the type consumed by 75 percent of Americans, has no effect on cholesterol levels, so coffee may influence heart disease risk by other unknown mechanisms besides raising blood fat levels.
In short, coffee and/or caffeine consumption is associated with an increased risk of heart disease only when a person consumes more than three to five cups a day. Moderate intake appears safe, while tea consumption at at dose has not been linked to heart disease risk.Â
The scientific evidence linking coffee with cancer is also confusing. Caffeine might encourage the growth of tumors depending on the person’s exposure to cancer-causing substances in the environment, the type of cell affected, and the stage of cell replication. One study on rats showed that caffeine increased the risk of cancer fivefold when the animals were also deficient in the B vitamin folic acid. The amount of caffeine used in this study approached typical doses consumed by some adults. If coffee does have cancer-promoting effects, it might be a result of other compounds in the brew rather than the caffeine since cola (another caffeine-containing beverage) is not associated with an increased cancer risk. Tea consumption also shows little or no increased risk of cancer.Â
Tannins and other compounds in coffee and tea reduce mineral absorption, especially iron, by as much as 90 percent and can rob the body of other minerals, such as calcium. Two cups or less each day apparently pose no health risk, but one study reported that intakes greater than this could cause calcium imbalances and increase the risk of developing osteoporosis. Consequently, women should drink coffee and tea between meals rather than with food to minimize the effects of these beverages on mineral status and the risk of anemia and osteoporosis. Consuming extra vitamin C at a meal helps counteract the effects of coffee on iron absorption.