In an unsettling finding, the medical journal JAMA Internal Medicine reports this morning that although daily apple eaters are less likely to use prescription medications, "Evidence does not support that an apple a day keeps the doctor away."
"People who eat an apple a day are a little more likely to keep the doctor away, but once we adjusted for all the other differences—as you can imagine, apple eaters are very different from non-apple eaters—the effect disappeared," said Matthew Davis, an assistant professor at the University of Michigan.
Davis and colleagues reviewed data from 8,728 consumers of food. Nine percent, it turned out, were daily apple eaters. Those people were less likely to smoke and had higher average education levels than the non-apple-a-day majority. The daily-apple people also were more likely to be from racial and ethnic minorities. They were not, however, any less likely to have seen a doctor more than once during the past year.
"We debated, what does it mean to 'keep the doctor away?'" Davis, who admits he's a health-services researcher, not a nutrition expert, recalls. "I always thought the phrase was funny, because there's a big difference between health status and healthcare use. People assume that they go hand in hand, but they're very different things from our perspective, and they don't always go in the direction you imagine."
The researchers settled on one annual visit still qualifying as keeping the doctor away, but any more than that constituted apple failure. The researchers did not account for the fact that almost everyone eats their apples wrong (from the side instead of the bottom, discarding the core like a legit monster). As NPR reported earlier this year, there is evidence that an avocado a day is beneficial—in one study it seemed to help people by lowering LDL cholesterol—so a new mantra may be in order. ("An avocado a day helps lower LDL cholesterol, which may keep the doctor away later in life, in that it may decrease one's risk of ending up hospitalized with coronary artery disease. Although the same might also be true of apples.")
Because eating daily apples is associated with using fewer prescription medications, which account for nearly one-third of out-of-pocked healthcare spending, the researchers also suggest in the paper that "in the age of evidence-based assertions, there may be merit to saying, 'An apple a day keeps the pharmacist away.'"
At the risk of jeopardizing the jaunty lightness of today's research paper, the press release carries a note from the editor of the medical journal, cardiologist Rita Redberg: "Although we take seriously the statement, 'An apple a day keeps the doctor away,' these articles launch our first April Fool's issue. At least once per year, and more is likely better (but needs to be tested), laughter is the best medicine. We look forward to continued editorial chuckles." So do we all.
The data in this study is real, so the line walked by the humor is fine—in the tone and premise of the study, but not the execution.
"I try to do stuff like this every year or two just to remind myself that research can be fun," said Davis, who recognized the potential for today's data analysis while studying American rice consumption as part of an evaluation of arsenic exposure in children.