We’re pleased to publish another guest post by Timothy Caulfield, who is a Canada Research Chair in Health Law and Policy at the University of Alberta, a Trudeau Fellow and the author of “Is Gwyneth Paltrow Wrong About Everything?: How the Famous Sell Us Elixirs of Health, Beauty & Happiness” (Beacon Press, 2015).

It is flu season again. And this means that we will be hearing a ridiculous amount about how we can boost our immune system. It is an autumn tradition. The leaves turn color, little kids in costumes expect candy and we are told that some food, drink, supplement or activity (like sex!) will hypercharge our immune system. We will hear it from TV doctors (you know who), celebrity wellness and lifestyle gurus (again, you know who) and a myriad of wellness magazines, websites and all-natural salesmen.

But can this be done? Can we use berries, sweet potatoes, and supplements to fend off the flu?

The promise to “boost your immune system” is one of those fairy-dust-like health claims that is hard to critique because, well, who knows what it actually means? Like many of its health-verbiage cousins – energize, revitalize, cleanse, detox, etc. – pumping up your immune system sounds like a fine idea (who wouldn’t want to have a super immune system?), but there is usually no science or, even, common sense behind the vast majority of the promises.

When you hear that a herb, supplement or super food will help you build a “bullet proof” immune system, as one well-known website claims, you need to ask, what, exactly, is being bullet-proofed?

The immune system is, in fact, ridiculously complex – one of the most complicated systems in the human body. There isn’t one germ-busting organ that can be built up or special vitalistic bodily fluid that can be hyper-charged to help you fight off the seasonal flu. The immune system involves numerous organs, cells and proteins that coordinate to identify and neutralize pathogens, like bacteria, viruses and fungi. “Boosting” this web of delicately balanced biology is far from easy.

Does anything work?

The evidence around supplements is very mixed, to put it in the kindest terms possible. Despite the fact that it is a multi-billion industry, there is no solid evidence to support the consumption of supplements for the purpose of boosting your immune system. Not for vitamin A, B or C. Admittedly, the research on vitamin D supplementation is evolving. But even here, little can be said definitively. And a few studies have suggested that some supplements can hurt the immune system.

A similar level uncertainty exists with herbal products, such as Echinacea. A 2014 systematic review concluded that the existing studies of Echinacea products have not shown that it provides any benefits for treating colds.

I think it wise to completely ignore all the immune-system-boost noise. As with so many topics in the health and wellness domain, the intuitive appeal of the rhetoric has overwhelmed the reality. There is no magic solution.

What is the best way to ensure your immune system is working well? Take care of yourself. [Warning: “Duh” prompt forthcoming.] And this means don’t smoke, get enough sleep, eat a healthy diet and exercise. It also means doing one of the few interventions that does help you immune system fight pathogens: get a flu shot.

That’s it. No boost bunk required.

Timothy Caulfield previously wrote for us about how to Freeze your ass off, celebrity style.