This is a MYTH.
Old wives’ tales have remarkable staying power, as attested by the longstanding myth: starve a fever feed a cold. The myth dates back to 1574 in a dictionary entry by John Withals that reads, “fasting is a great remedy for fever,” advice that doesn’t hold up in lieu of what we know of colds and flus today. Staying well hydrated and eating a balanced amount of nutrient-dense food is the best prescription for wellness.
The Origins of the Myth
In the 1500s, medicine was ruled by a theory of humours. Optimal health was determined by the appropriate balance of bodily fluids (aka humours): yellow bile, black bile, blood, and phlegm. A fever indicated too much blood and heat, and the patient was either bled, fasted, or both (we now know neither is an effective treatment for reducing fever and treating illness). A cold that generated a prevalence of phlegm in the form of mucous was fed an abundance of food as a way to stoke heat in the body. Modern medicine, however, confirms that while the body needs energy to fight cold viruses, it doesn’t require extra energy—just antioxidants and nutrients from a well-balanced diet to help fight infection.
The Facts for Treating Fevers and Colds
Your body fights flu and cold bugs by raising its temperature and firing up a fever. When your body temperature rises, more calories are burned, so it’s important to feed, not starve a fever in order to sustain energy in the body. Fever likewise dehydrates the body, so drinking fluids is imperative. Dehydration causes mucous to dry up, which can lead to clogged sinuses and respiratory tubes. While runny noses are no fun, mucous is part of the body’s natural defense mechanisms.
Treat colds and flus by eating foods replete with nutrients that help activate your immune system, like beta-carotene and vitamins C and E. Bioflavonoids have been shown to boost the immune system as well. The pulp and white core in the center of citrus fruits, green peppers, cherries, lemons, oranges, and grapes, deliver a substantial helping of bioflavonoids. Broccoli and red and yellow onions are high in quercetin, a richly concentrated source of bioflavonoids.
Feed a cold and fever with glutathione, abundant in broccoli, Brussels sprouts, and spinach (three vegetables loaded with phytochemicals and other antioxidants!).
Add some eggs, seafood, wheat germ, and grains to your diet when you are fighting off a cold or flu. These foods are packed with zinc, shown to lessen the severity and duration of illness.