According to the U.S. Food and Drug Administration, 90% of people worldwide, and 80% in the US, consume caffeine in some form every day. The average adult has an intake of about 200 milligrams, or roughly one cup of coffee per day.
As one of those few non-coffee-drinking adults–probably rarer still among emergency medicine providers–I was intrigued by today’s New York Times review of the risks and benefits of coffee consumption. Given that most evidence is observational, not based on randomized trials, it is hard to draw causal relationships between coffee intake and various outcomes. Nonetheless, the accumulation of evidence led the U.S.D.A. to address coffee in its latest nutritional guidelines, guidelines I have discussed before. On coffee, the guidelines state:
Currently, strong evidence shows that consumption of coffee within the moderate range (3 to 5 cups per day or up to 400 mg/d caffeine) is not associated with increased long-term health risks among healthy individuals. In fact, consistent evidence indicates that coffee consumption is associated with reduced risk of type 2 diabetes and cardiovascular disease in adults. Moreover, moderate evidence shows a protective association between caffeine intake and risk of Parkinson’s disease. Therefore, moderate coffee consumption can be incorporated into a healthy dietary pattern, along with other healthful behaviors. However, it should be noted that coffee as it is normally consumed can contain added calories from cream, milk, and added sugars. Care should be taken to minimize the amount of calories from added sugars and high-fat dairy or dairy substitutes added to coffee.
After reviewing the evidence (Chapter 5), the report concludes that those who are not consuming coffee should not commence coffee consumption for health benefits alone.
The Well blog presents potential benefits as well as risks of moderate coffee consumption, and draws the same conclusion as the USDA guidelines.
“It’s one thing to say it’s safe,” said Dr. Rob van Dam, an adjunct associate professor of nutrition and epidemiology at Harvard University. “It’s another thing to recommend it as a medical choice even though people don’t like it and they’d have to make an effort to adopt it. We’d need a different level of evidence to recommend it to people.”
The experts’ hesitance to recommend changing coffee-drinking behavior is not surprising, given the “level of evidence”: the evidence pro- and con-coffee is epidemiologic, that is, based on observations of patterns.
The Incidental Economist, in the Times’ Upshot column, takes this perspective slightly further, noting that the evidence shows it is time to move away from traditional admonitions urging all coffee-drinkers to cut down.
It’s a completely reasonable addition to a healthy diet, with more potential benefits seen in research than almost any other beverage we’re consuming.
On the other side–exemplified by a Forbes article “Caffeine: The Silent Killer of Success”, coffee still has addictive properties and needs to be used with caution, if at all.