"An apple a day keeps the doctor away" is a common English-language
proverb
A proverb (from la, proverbium) is a simple and insightful, traditional saying that expresses a perceived truth based on common sense or experience. Proverbs are often metaphorical and use formulaic language. A proverbial phrase or a proverbia ...
that appeared in the 19th century, advocating for the consumption of apples, and by extension, "if one eats healthful foods, one will remain in good health and will not need to see the doctor often."
Origin
A variant of the proverb, "Eat an apple on going to bed, and you'll keep the doctor from earning his bread" was recorded as a
Pembrokeshire saying in 1866.
The modern phrasing, "An apple a day keeps the doctor away", began usage at the end of the
19th century, with early print examples found as early as 1887.
Scientific background
A 2013 study using
computer modelling
Computer simulation is the process of mathematical modelling, performed on a computer, which is designed to predict the behaviour of, or the outcome of, a real-world or physical system. The reliability of some mathematical models can be det ...
compared eating apples with taking a
common daily cholesterol-lowering drug to estimate risk of
cardiovascular diseases
Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, ...
.
The computer model estimated that eating an apple a day was generally comparable for people over age 50 years to using a statin drug to reduce
low-density lipoprotein cholesterol
Low-density lipoprotein (LDL) is one of the five major groups of lipoprotein that transport all fat molecules around the body in extracellular water. These groups, from least dense to most dense, are chylomicrons (aka ULDL by the overall densit ...
, concluding that eating an apple a day "is able to match modern medicine and is likely to have fewer side effects," while having similar annual cost.
[
A 2015 study found apple eaters "were more likely, in the crude analysis, to keep the doctor (and prescription medications) away." When they adjusted for "sociodemographic and health-related characteristics, however, the association was no longer statistically significant”. The study also found that people who ate an apple a day used fewer ]prescription medication
A prescription drug (also prescription medication or prescription medicine) is a pharmaceutical drug that legally requires a medical prescription to be dispensed. In contrast, over-the-counter drugs can be obtained without a prescription. The r ...
s.[
]
Nutritional content of an apple
A medium-size (100 gram) raw apple is 86% water and 14% carbohydrate
In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or m ...
s with negligible content of fat
In nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such compounds, most commonly those that occur in living beings or in food.
The term often refers specifically to triglycerides (triple est ...
and protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...
, and supplies 52 calories of food energy
Food energy is chemical energy that animals (including humans) derive from their food to sustain their metabolism, including their muscular activity.
Most animals derive most of their energy from aerobic respiration, namely combining the carbohy ...
.[
]
References
{{Wiktionary
1880s neologisms
Apples
English proverbs
Health effects of food and nutrition
Metaphors referring to food and drink