On the Stuff You Should Know podcast, Josh Clark and Chuck Bryant tackle the age-old advice, "Feed a cold, starve a fever." First, they trace the origins of this saying, revealing its 16th-century roots and widespread popularity by the mid-19th century.
However, the hosts then explain how modern medical experts overwhelmingly advise against this practice. They discuss a 2002 Dutch study demonstrating how fasting can significantly impair the immune system's response. In contrast, nourishing the body supports immune function and recovery from illness. Through their analysis, Clark and Bryant make a compelling case for discarding this outdated adage.
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This advice first emerged in the 16th century, when John Whithalls stated that "fasting is a great remedy of fever," per Josh Clark. The full phrase arose in the mid-18th century, gaining popularity by the 1850s.
Today's experts overwhelmingly agree this advice is ill-advised and potentially harmful. Chuck Bryant explains forcing food when sick can disrupt digestion, while starving a fever deprives the body of nutrients and fluids vital for recovery.
As Bryant notes, a Dutch study found fasting for 24 hours led to an 83% drop in the key immune protein [restricted term] gamma. Conversely, a meal replacement increased [restricted term] levels, boosting the immune response. The study also observed rises in interleukin-4 levels with fasting, suggesting fasting alters immune defenses unpredictably.
1-Page Summary
The saying "feed a cold, starve a fever" has been a common piece of health advice for many years, with its roots dating back centuries.
The concept of "starving a fever" can be traced back to the 16th century, specifically to the year 1574. Josh Clark references a dictionary from that time compiled by John Whithalls, which included the statement "fasting is a great remedy of fever," representing the origins of the "starve a fever" portion of the saying. This belief held that withholding food could potentially help in managing a fever by reducing the body's need for energy.
As for the complete advice as we know ...
The history and origins of the "feed a cold, starve a fever" advice
Medical experts today widely regard the old adage "feed a cold, starve a fever" as outdated and even harmful.
If you have a cold, you may not feel very hungry. Medical advice suggests that it's best not to force yourself to eat. Eating large amounts when lacking an appetite can be counterproductive because your body may not be primed to digest food efficiently while unwell.
Conversely, the advice to "starve a fever" is considered especially problematic. When fighting a fever, your body requires adequate nutrition and hydration. Fasting when feverish can deprive the body of the necessary nutrients and calories it needs to combat the infection.
Forcing yourself to eat while sick can be unhelpful, but it's crucial that you don't entirely for ...
The current medical consensus on this advice, and why it is considered poor advice
A study by Dutch researchers in 2002 explored the relationship between food intake, fasting, and the immune system. Their findings suggest that fasting and eating can have opposite effects on our body's immune response when sick.
The research indicated that individuals who fasted for 24 hours experienced a sharp decline in their immune system's capabilities. Specifically, there was an approximate 83% reduction in levels of [restricted term] gamma, which is a crucial immune protein involved in the body's targeted immune response against pathogens. The implication from this part of the study was clear: fasting may weaken the immune system's ability to respond to illnesses.
On the flip side, the study observed that a group which consumed a meal replacement showed a marked increase in [restricted term] gamma levels after fasting. This indicates that instead of fasting, consuming calories and nutrients can have a beneficial impact on certain aspects of the immune response at a time when the body is fighting an infection or other illness.
The scientific evidence on how eating and fasting affect the immune system when sick
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