Views / Citizen Scientist

In this awful flu season, is there a way to boost my immune system?

If you’re generally healthy, there isn’t much you can do to get immunity superpowers, cool as that would be.

Echinacea might be able to shorten your cold slightly, but the data are mixed and the effect is very small.

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Echinacea might be able to shorten your cold slightly, but the data are mixed and the effect is very small.

Does zinc, echinacea or vitamin C help boost the immune system? - Levon, Toronto

Given what a gnarly cold and flu season we’re in, I wish I had some better news for you. Alas, no.

The first thing to ask when someone claims this or that potion “boosts the immune system” is “Which part of it?” The immune system isn’t one thing. It’s physical barriers, specialized cells and response mechanisms all working together to fight off invaders like cold and flu viruses.

The second thing to ask is “what are the side effects?” A true, measurable, significant boost to the immune system can leave you feeling pretty crummy. Ever gotten a shot of interferon to help rev up the inflammatory response your body uses to fight a virus? The disease-fighting proteins released into the blood are the same ones you get from a hangover. What about sargramostim, which helps make white blood cells if yours have been wiped out by chemo? One of the side effects is “bone pain.” Ick.

It’s true your immune system may fall down on the job if you’re stressed, malnourished, smoking, or deficient in essential vitamins or minerals. But if you’re generally healthy, there isn’t much you can do to get immunity superpowers, cool as that would be.

On to specifics: There’s a bit of evidence, from reviews of previous studies, that taking echinacea or zinc supplements may shorten the duration of colds very slightly.  But the data are mixed and the effect is small to insignificant, especially in the case of echinacea. Getting enough vitamin C helps you have fewer colds, but it doesn’t do much once you’re sick.

A vitamin D researcher I spoke to once reminded me of something else:  Some studies that find that vitamin supplements have a benefit (i.e. a vitamin prevents colds), didn’t screen people for deficiency. The pills didn’t give people extra immunity: They fixed what was broken, allowing the immune system to work as it should.