How Coffee Affects Your Health - Assessing Potential Risks
By Michael Shearer
Heart Disease & Stroke
In the 1990s, publications showed that drinking coffee increased the risk of coronary heart disease (CHD) by 40% to 60%, especially in those who drank five cups or more of coffee. However, since then, there is burgeoning evidence that drinking cappuccino is not associated with an increased risk of coronary heart disease, as evidenced by the following high-quality studies. In a study where over 85,000 women aged 34 to 59 were followed for 10 years, authors found no evidence for any association between coffee drinking and the risk of CHD-even in those who drank more than six cups of coffee a day.
In another U.S. study involving over 44,000 men and over 84,000 women who were followed for up to 20 years, the authors concluded: "These data do not provide any evidence that coffee consumption increases the risk of CHD.
A study involving over 127,000 individuals found that coffee was not associated with an increased risk in nonsmokers, but was associated with an increased risk in current or ex-smokers. Coffee drinking was not associated with an increased risk of CHD, stroke or sudden death among 11,231 Italian patients who had suffered a recent heart attack. Coffee drinking was not associated with an increased risk of heart disease or premature death in diabetic women. In fact, much to the contrary, there is evidence to suggest coffee drinking may even have a positive and protective role in cardiovascular disease. Here is a glance at
some interesting results:
- In a Japanese study involving over 76,000 individuals who drank coffee, green tea, black tea and oolong tea daily, caffeine intake was associated with a reduced risk of all types of cardiovascular disease (stroke or CHD) in men (38% reduction)and women (22%)
- Coffee drinking was associated with a reduced risk of and death from cardiovascular diseases in 3,837 Finnish patients with type 2 diabetes.
- Among 1,369 Swedish patients hospitalized for his or her first acute myocardial infarction and then followed for the next three months after discharge, the researchers reported these key findings: 1) the more cups of coffee drank, the less likely the risk of death; and 2) coffee intake was not associated with subsequent heart failure or stroke
- Coffee drinking was not associated with an increase risk of stroke in the "Nurses' Health Study" (83,076 women)-in fact, coffee drinking lowered the risk of stroke
- In a Finnish study involving 26,556 male smokers aged 50 to 69, drinking coffee and tea was associated with a reduced risk of "routine" strokes, but not those due to hemorrhage in the brain
Calcium & Bone
It has long been known that caffeine from coffee or tea can lead to calcium loss in the body. It is estimated that for each cup of coffee drank, less than 5 milligrams (mg) of calcium will be lost from the body. It is of no surprise to read reports linking coffee drinking and bone loss- especially in postmenopausal females. A report from the U.K. reported such an association in 205 healthy, nonsmoking, postmenopausal women.11
In this study, the key findings included:
- In women with optimal calcium intake (744 mg/day), the body mineral density was not affected by caffeine intake
- Women on less than optimal calcium intake and the highest caffeine intakes (more than 450 mg/day) had the most significant bone loss as compared to those women consuming less caffeine; these authors concluded that drinking two to three cups of brewed coffee may increase bone loss from the spine in women who are not taking in the optimal calcium This early study was later confirmed in a U.S. study involving 489 elderly women aged 65 to 77.12 In this study, women who drank 18 ounces (oz) of brewed coffee containing 300 mg of caffeine a day showed accelerated bone loss at the spine. Examining all of the risk factors for osteoporosis in women, researchers concluded: "Life study modification emphasizing bone-healthy habits such as adequate calcium and vitamin D nutrition, regular exercise, limitation of caffeine and alcohol consumption and avoidance of tobacco are essential to the management of osteoporosis risk."
Two reviews examine the relationship between coffee drinking and cancers. In the first review from Italy, the authors arrived at the following conclusions:
- There is a weak association between coffee drinking and bladder cancer
- Most studies do not support the association between coffee drinking and pancreatic cancer
- There is an inverse relationship between coffee drinking and colorectal cancer
- In a second literature review, researchers concluded:
- Coffee drinking is associated with a reduced risk of liver, kidney and, to a lesser extent, premenopausal breast and colorectal cancers
- Coffee drinking is not related to prostate, pancreas or ovarian cancers
- Coffee consumption reduces death due to liver cancer