An Apple a Day Keeps the Doctor Away
"The old promise that eating an apple daily will keep you healthy and out of the doctor's care."
Welsh in origin. The earliest recorded version is a Pembrokeshire saying from 1866: "Eat an apple on going to bed, and you'll keep the doctor from earning his bread." It drifted through a few variations, "an apple a day, no doctor to pay," "an apple a day sends the doctor away," before settling into today's phrasing by the 1880s-90s. Apples were a genuinely reliable, storable food through the colder months when fresh produce was scarce, real nutritional value behind the saying, just oversold as literal medical prevention.
Myth vs. FactNo clinical trial has shown a literal apple a day prevents doctor visits, but apples are a genuinely healthy, fibre-rich food. The saying overstates specificity, not the underlying idea.
Sources: Pembrokeshire saying recorded 1866; modern phrasing documented in print by 1887.