The saying "An apple a day keeps the doctor away" is an old English proverb that dates back to the 19th century. It originated in Wales and was first recorded in a publication called "Notes and Queries" in 1866. The original phrase was slightly different, stating "Eat an apple on going to bed, and you'll keep the doctor from earning his bread."
The exact origins of the saying are unclear, but it reflects the belief that consuming apples regularly as part of a healthy diet can contribute to overall well-being and potentially reduce the need for medical attention. The saying became popular and has been passed down through generations as a way to promote the benefits of eating nutritious foods and maintaining good health.