“Hey, Doc, Is It OK for Me to Drink Coffee?”

Article Outline

Many of my patients with coronary artery disease, diabetes, or hypertension have been warned at various times in their lives to avoid caffeinated coffee because they had been informed that drinking caffeinated coffee could result in increased blood pressure, worsening of diabetic control, and might even trigger a myocardial infarction. Some of my patients also worry that drinking caffeinated coffee might cause cancer. This editorial will briefly cite the now-voluminous evidence that caffeinated coffee in moderate doses (1-3 cups per day in some studies and more in other investigations) is not associated with clinically relevant increases in blood pressure, serum cholesterol levels, myocardial infarction, or various malignancies.

In the past, some retrospective studies suggested that caffeinated coffee consumption was associated with cardiovascular morbidity and mortality. Other studies suggested that coffee might cause pancreatic cancer.1 All of these older studies have now been discredited.1, 2, 3, 4, 5, 6, 7, 8, 9, 10 I am personally overjoyed by this news because I love my morning cup of strongly brewed coffee!! Current thinking about caffeinated coffee consumption can be summarized as follows:

1.Caffeinated coffee consumption causes only minor increases in blood pressure in individuals who do not drink coffee regularly. However, this increase rapidly disappears when coffee is consumed regularly.1, 5, 6 Caffeinated coffee consumption does not cause hypertension.

2.Caffeinated coffee consumption does not cause myocardial infarction, nor does it increase the frequency of anginal attacks in patients with established coronary artery disease. In fact, recent studies suggest that caffeinated coffee consumption actually decreases the risk for the development of cardiovascular disease.1, 2, 3, 7

3.Caffeinated coffee consumption does not cause serum levels of total or low-density lipoprotein cholesterol to rise.2

4.Caffeinated coffee consumption does not increase the frequency of cardiac arrhythmias even in patients with a history of malignant ventricular arrhythmias.1, 8, 9

5.Caffeinated coffee consumption does not result in worsening of diabetic control, and it does not increase the risk for diabetic complications.1, 10 This latter point assumes that diabetic patients don't take a lot of sugar or eat doughnuts with their coffee!! There are data from the Health Professionals Follow-up Study demonstrating that caffeinated coffee consumption may actually decrease an individual's risk for developing type 2 diabetes mellitus.10

6.There is no evidence that caffeinated coffee consumption increases the risk for any form of malignancy.1 There is also no conclusive evidence that caffeinated coffee consumption increases the risk of fibrocystic breast disease in women.1

7.Caffeinated coffee consumption can cause mild to moderate sleep disturbances, but habitual coffee consumers usually develop tolerance with resulting resolution of this irritating symptom.

8.Habitual caffeinated coffee consumption does result in tolerance to caffeine with resultant mild withdrawal symptoms—often headache—if caffeinated coffee is withheld.

9.It is true that caffeinated coffee can cause gastrointestinal distress in the form of “heartburn” in some individuals. However, this is not the result of caffeine, because similar symptoms can be elicited with decaffeinated coffee. By the way, so-called decaffeinated coffee still contains small amounts of caffeine as well as many other organic compounds, including antioxidants.4

So, lovers of that morning (or afternoon or perhaps even evening) cup of Java, partake and enjoy this mild and perhaps beneficial addiction.

As always, I'd be interested in hearing your comments on this important topic. Feel free to send me an e-mail or post a comment on our blog, http://amjmed.blogspot.com.

References

1. 1Curatolo PW, Robertson D. The health consequences of caffeine. Ann Intern Med. 1983;98:641–653. MEDLINE

2. 2Wilson PWF, Garrison RJ, Kannel WB, et al. Is coffee consumption a contributor to cardiovascular disease?. Arch Intern Med. 1989;149:1169–1172. MEDLINE

3. 3Lopez-Garcia E, van Dam RM, Li TY, Rodriguez-Artalejo F. The relationship of coffee consumption with mortality. Ann Intern Med. 2008;148:904–914.

4. 4Greenberg JA, Chow G, Ziegelstein RC. Caffeinated coffee consumption, cardiovascular disease, and heart valve disease in the elderly (from the Framingham Study). Am J Cardiol. 2008;102:1502–1508. Abstract | Full Text | Full-Text PDF (154 KB) | CrossRef

5. 5Robertson D, Hollister AS, Kincaid D, et al. Caffeine and hypertension. Am J Med. 1984;77:54–60. Abstract | Full-Text PDF (785 KB) | CrossRef

6. 6Myers MG. Effects of caffeine on blood pressure. Arch Intern Med. 1988;148:1189–1193. MEDLINE

7. 7Piters KM, Colombo A, Olson HG, Butman SM. Effect of coffee on exercise-induced angina pectoris due to coronary artery disease in habitual coffee drinkers. Am J Cardiol. 1985;55:277–280. MEDLINE | CrossRef

8. 8Myers MG, Harris L, Leenen FHH, Grant DM. Caffeine as a possible cause of ventricular arrhythmias during the healing phase of acute myocardial infarction. Am J Cardiol. 1987;59:1024–1028. MEDLINE | CrossRef

9. 9Graboys TB, Blatt CM, Lown B. The effect of caffeine on ventricular ectopic activity in patients with malignant ventricular arrhythmias. Arch Intern Med. 1989;149:637–639. MEDLINE

10. 10Salazar-Martinez E, Willet WC, Ascherio A, et al. Coffee consumption and risk for 2 diabetes mellitus. Ann Intern Med. 2004;140:1–8.

University of Arizona College of Medicine, Tucson

PII: S0002-9343(09)00094-1

doi:10.1016/j.amjmed.2009.01.011

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