Why Feed a Cold & Starve a Fever

The old saying “feed a cold, starve a fever” may actually be very good advice.  A recent study published in the journal Cell found that eating food during an infection appeared to influence the immune system’s ability to fight the pathogens depending on what type of foods were eaten and whether the pathogens were bacterial or viral.

Using mice, researchers either fed or starved the mice that had been infected with bacteria or viruses. 

One group of mice was infected with a bacterium known to cause food poisoning called Listeria monocytogenes. After being infected, this group of mice stopped eating which commonly goes along with food poisoning and did make a full recovery.  But when the researchers force-fed the mice that were infected with this bacterium, they died.  What was found to be fatal to the mice was the sugar glucose from carbohydrates – fat and proteins did not have an effect.  However, when researchers administered the chemical 2-DG inhibiting glucose metabolism – the mice that were force-fed did not die making glucose no longer fatal.

For the second group of mice, the researchers infected them with the flu virus A/WSN/33.  The results from this group was that the mice force-fed with glucose actually survived but mice given the chemical 2-DG inhibiting glucose metabolism, died from being starved of glucose.

When researchers analyzed scans of the brains of mice dying from either the bacterial or viral infection, it was discovered each infection affected different areas of the brain.  This suggested that the metabolic requirements of the mice may have been determined by what part of their immune system was switched on.

The results from this study are believed to have important implications for research into sepsis – a potentially fatal blood infection. A few studies have researched into whether a person’s nutrition or food choices with sepsis with mixed results.  However, the studies did not differentiate the patients based on whether their sepsis was bacterial or viral which could possibly have an impact on how they well they are able to recover from this condition or not.