Apples have long been associated with a healthful diet, but just how old is the adage "An apple a day keeps the doctor away"?

"It sounds as if it should be really old, but, in fact, the first recorded use is in the 1860s," said Caroline Taggart, author of "An Apple a Day: Old-Fashioned Proverbs and Why They Still Work."

Taggart traces the original phrase, which was "Eat an apple on going to bed, and you'll keep the doctor from earning his bread," to Pembrokeshire in Wales. It later evolved to "an apple a day, no doctor to pay" and "an apple a day sends the doctor away." The phrasing now commonly used was first recorded in 1922.

But while the saying may be relatively new, Taggart said, the concept is quite old.

Ancient Romans and Anglo-Saxons knew about the healthful properties of apples. The fruit also pops up in traditional Ayurvedic medicine, dating back about 1,500 years in southern Asia.

Modern science has put the adage to the test. Researchers have conducted numerous studies on the health benefits of apples, exploring whether they can actually reduce trips to the doctor. In 2012, an Ohio State University study found that eating an apple a day helped to significantly lower levels of bad cholesterol in middle-aged adults. A Dutch study, completed a year earlier, found that eating apples and pears might help prevent strokes.

The longevity of the phrase "an apple a day," is likely due to its simplicity — and its accuracy.

"One of the odd things about this proverb is that it means exactly what it says," Taggart said. "You can take it at face value."

Washington Post