Be they about eating healthier, getting more rest, or exercising, the modern vernacular abounds with "doctor-recommended" tips. But which health-focused proverbs are actually legit? Here are some catchphrases that actually offer great advice for staying out of the doctor's office.
"An apple a day keeps the doctor away"
This expression, first used in an 1866 U.K. newspaper, stated, “Eat an apple on going to bed, and you’ll keep the doctor from earning his bread.” The rhyming proverb was supported by several medical and scientific sources that suggested apples were a "superfood" of the era, and could soothe a stomach at night, among other miracle-working abilities.
Today, the expression is often shorthand for ingesting enough Vitamin C (associated with a healthy immune system). A study published in 2015 cited that 39% of regular apple eaters avoided more than one yearly doctor’s visit (compared with 33% of non-apple eaters), and they tended to use fewer prescription medications.
"Feed a cold; starve a fever"
This expression comes from a 16th-century dictionary that noted fasting was a great remedy for fevers. Very little medical advice from that time period has held up today, including this expression. The idea back then was that eating food would generate heat and help eradicate a cold, and fasting ("starving") would cool down the body during a fever. In general, modern doctors suggest that eating healthy foods and hydration are important to overcoming most sickness.
One 2016 study suggests a variation of this axiom: “Feed a virus, starve a bacteria.” After infecting mice with a flu virus and a bacteria linked to food poisoning, animals that were force-fed during the flu had a much higher survival rate, while animals that avoided additional food during the bacterial infection also had a better survival rate.
"Sleep is the best medicine"
The Irish proverb, “A good laugh and a long sleep are the best cures in the doctor's book,” is often shortened to “Sleep is the best medicine,” but the meanings are similar. There is no substitute for rest and relaxation when it comes to getting better. This one is accurate. Processes related to your immune system and sleep overlap. During sleep, the body is less occupied with basic functions such as walking, talking, thinking, and eating. If the body is resting, it can instead focus on fighting off illness. In fact, sleep boosts production of a protein that’s linked to speeding up recovery from illnesses like the flu.
"An ounce of prevention is worth a pound of cure"
Benjamin Franklin introduced this saying, but he was talking about fire prevention. But the intent holds true for physical health. Prevention is much easier than cleaning up a mess (or curing an illness) after the fact. While Franklin’s expression wasn’t medical in nature, doctors will no doubt nod appreciatively at the sentiment. Many medical studies have supported the importance of getting enough rest, eating a healthy diet, and engaging in exercise to minimize short-term illness and chronic disease.