An Apple a Day Has a Negligible Effect on Your Health
Despite what you've heard, an apple a day doesn't keep the doctor away—at least, so says a study full of mitigating clauses and obvious assertions. Researchers considered data on about 8400 U.S. adults who took part in government health surveys in 2007-'08 and 2009-'10 for a study published this week in JAMA Internal Medicine that considers the relationship between regular apple-eating and overall health. The original findings, which showed a slight correlation between the proverb-approved fruit and fewer doctor visits, were negated by considering weight, race, education, health insurance, and other factors that can influence frequency of medical visits.
Of course, there are some issues with a study that compares incredibly stringent parameters—the AP says "about 9 percent of adults studied ate the equivalent of at least one small apple daily. Those who ate less than that were considered apple shunners"—to something as vague as annual doctor appointments. The study fails to include the nature of the doctor visits and relies on self-reporting of diet (I have doubts about you 9-percenters who claim to eat an apple every single day).
The study did find a correlation between daily apple consumption and less use of prescription drugs, but even the authors admit that their findings "suggest that the promotion of apple consumption may have limited benefit in reducing national health care spending." They posit an updated version of the popular proverb to reflect their limited results: "In the age of evidence-based assertions, however, there may be merit to saying ‘An apple a day keeps the pharmacist away.'"