Sometimes the oldest sayings are the best. Advice handed down through the generations can be trustworthy wisdom. Eating apples is most certainly good for health and will go some way to ‘keep the doctor away’. Likewise, not letting the sun go down when you’re angry is an aid to improving marital harmony.
A lot of the time old wives’ tales are wrong, but sometimes useful. Cold weather does not cause a cold – but it is not good to be in a blizzard if you’re unwell. Chocolate does not cause acne – but eating too much is never a good thing. Most of the body’s heat is not lost through the head – but a lot is, and so wearing a hat is wise.
Should you ‘feed a cold’? This certainly falls into the ‘good advice’ category. Any doctor, me included, would stress the importance of good nutrition when fighting off an infection. The immune system can consume vast amounts of energy when it is firing on all cylinders.
On a similar logic ‘starving a fever’ makes little sense – although there is some research that suggests it might just be true. The 2002 study showed that eating a meal enhanced the immune system’s virus-killing abilities (viruses being the cause of the cold); whereas fasting enhanced its bacteria-fighting powers (bacteria being a cause of fever).
It is headline grabbing stuff, but I’m not convinced. The research was done on only six volunteers, all of whom were perfectly fit and healthy; and bacteria do tend to cause the worst fevers – but viral infections cause fevers also. Most importantly, when going through a fever, our metabolic rate sky-rockets. Not eating when in such a state will deprive the body of the fuel needed to sustain itself. The pounds may fall away, but you’ll be pig-sick.
On balance, it would appear sensible to keep eating through a cold or a fever – even if sustenance is in non-solid form (chicken soup, anyone?):
‘Feed a cold, feed a fever and drink plenty’
Tummy bugs from food poisoning are a bit different and are rather messy affairs. But we’ll leave that for another day…
Answer by Dr Stu
Question from UOPscience via Twitter