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Boosting your immune system

August 2, 2012
Let’s check the science: Is it possible to boost my immune system? 

It’s the middle of winter and I’m constantly advised by advertising material that to remain healthy I should be doing or taking something to strengthen my immune system. Some people I know are convinced that it works. Although I’m perfectly healthy and I’ve even had this year’s flu shot, I know it won’t protect me against every virus that comes along. Should I join them?

This article assumes you are happy to accept science as the best way of discovering the truth about the natural world. If that’s not the case for you, why not have a look at Trusting the science first?

The promoters’ arguments – science or red flags?

There’s an astonishing variety of claims about all sorts of products and practices that can ‘boost’, ‘strengthen’, ‘stimulate’ or ‘support’ your immune system. Some examples:

“Probiotics work within your digestive system to not only stabilise gut flora, but support immune responses which in turn, promote the gut immune defences.” (here)

“Astra 8 Immune Tonic contains the herb Astragalus and seven other potent immune system boosting herbs. The herbs in Astra 8 Immune Tonic have been used for centuries to help people strengthen their body’s defences and restore good health.” (here)

“Aromatherapy is a great way to boost the immune system.” (here)

“I have taken echinacea once a week for 10 years, plus daily garlic. Reduced my 5 colds a year to 1 every 2 years.” (here)

Do I see any red flags? Yes indeed. I see appeals to ancient wisdom, anecdotal evidence, unsupported statements, and rooster syndrome in the above examples. Elsewhere, I also see claims of scientific proof (here), appeal to authority (here) and attempts to use analogies as evidence (comparing the immune system with muscles, here).

Much of the advice about boosting immunity seems to consist of general hints about a healthy lifestyle – eating properly, getting enough sleep, avoiding stress, exercising and so on (here). Nothing wrong with this, but is it really doing anything special for your immune system?

Being skeptical

I don’t know much about the immune system, but do I know that it’s extremely complex.  It seems to me that is would be nearly impossible to give a general ‘boost’ to this complex system just by a single simple treatment.

I also know that overactive immune systems are responsible for many diseases, such as asthma and rheumatoid arthritis. If it becomes too active, it can start attacking our own cells, or they can end up as collateral damage in the battle.

Basically, what I want to find out is: Can our immune system become overloaded or run down? Is it possible to boost your immune system? If so, is that a good idea?

The scientific evidence

It doesn’t take long to find out that the immune system is incredibly complex. It involves a huge variety of molecules, cells, tissues and organs, all working in different ways to tackle different types of pathogens. There aren’t any studies that test ‘boosting’ the immune system – it’s too much of a vague idea. For this reason I decided that trying to resolve the issue by going to original studies would get me nowhere. So looked for sources I can trust to find out what I wanted to know. These were: The US National Institute of Allergy and Infectious Diseases; Harvard Medical School; The European Federation of Immunological Societies; University of Rochester Medical Centre; Science-Based Medicine. From these sources, this is what I came away with:

  1. Some things – stress, malnutrition – can reduce the performance of your immune system. Some people are born with impaired immune systems, and others may acquire an immune deficiency as a result of certain diseases (HIV/AIDS is the classic example) or chemotherapy. But our bodies normally produce many more leucocytes (the white blood cells involved in immunity) than required, so your immune system does not become weakened merely because you have an infection of some kind.
  2. Most of us have perfectly adequate immune systems. Essentially, they identify and attack anything foreign in our bodies. We notice the immune response as an inflammation – swelling, redness, release of fluids. heat.
  3. Overactive immune systems are responsible for allergic conditions such as asthma and eczema (here). A runaway immune response known as a ‘cytokine storm‘ is responsible for causing deaths in severe flu pandemics and was the cause of near fatalities in a 2006 drug trial (here)
  4. The immune system can become misdirected and start attacking our own cells. This causes autoimmune diseases such as arthritis (herehere) and Type 1 diabetes (here).
  5. There is little evidence that a normally functioning immune system can be ‘boosted’. There is some evidence (here) that probiotics may help with the immune response, but it’s early days.
  6. ‘Boosting’ the immune system is probably not a good idea. Allergic reactions give us an indication of what happens when our immune systems are overactive.

DIY evidence

No chance of doing any DIY checking here. Too specialised. I could try an ‘immune booster’ myself, but anything less than a double-blind randomised controlled trial would be useless.


No ‘immune strengthener’ for me. I’m convinced that my immune system is fine, it’s not likely to become ‘run down’, and if it does, there’s no magic treatment that can ‘boost’ it. Even if there were, it could end up doing more harm than good. I’ll stick with having my immune system ‘primer’ (the flu shot) each year and stay clear of supplements that are unsupported by real evidence.

This is one of ScienceOrNot’s Let’s check the science series.

Contribute to ScienceOrNot. Leave a comment.

  1. Michael Simpson permalink

    Whenever I see something that “boosts the immune system,” my old skeptical radar usually blows out a few circuit boards. I was recently writing a scathing criticism of an internet meme that bananas cure cancer because it “contains tumor necrosis factor.” Well, it doesn’t. I was trying to describe how TNF works in the immune process, and I realized it would take at least 5000 words to just scratch the surface.

    The immune system is a hugely complex system dependent upon organs, cells, factors, proteins, and a bunch of other stuff. As you say, it is in perfect balance, unless you are very very ill, or are immunocompromised. There is just no way to make it better. How are you going to find something that will improve one of those organs, cells, factors, proteins and other stuff?

    And a funny thing while I was studying up on tumor necrosis factor (a crazy name that doesn’t quite mean what it sounds like it means). Too much TNF, and you get a whole bunch of autoimmune diseases. So, if bananas really could give you TNF (it can’t), it isn’t going to do what the altmed people think it’s going to do.

    Anyways, good job. I’m going to have to advertise this post.

    • Thanks Michael.

      I re-read your TNF post and your earlier Checking for pseudoscience in real science news one in preparing for this post. I can appreciate how much work you put into them. Amazing how the wishful thinkers will latch onto anything that involves escaping from real scientific analysis, isn’t it.

    • TNF is one of the proteins which make me dislike immunology. It got named after the first role in which it was observed but since then, it’s turned out to have many other roles too. And many other names, I expect… everything in immunology has about a dozen names! Still, I’m glad there are good immunologists. I can knock some of them flying when I talk about stats, so it’s horses for courses!

  2. Thank you for mentioning overactive immune systems and the diseases they cause. I have one of those diseases (multiple sclerosis). My immune system is like Genghis Khan! About the only thing that’s good about MS is that I almost never get colds any more

    • Good of you to share that with us. I like the way you look on the positive side. I count myself lucky in not having developed any autoimmune condition (so far, anyway).

  3. Frederick Bennett permalink

    There are some interesting double blind studies appearing in the literature looking at the effects of meditation on the immune system (eg Alterations in brain and immune function produced by mindfulness meditation. Psychosom Med. 2003 Jul-Aug;65(4):564-70 ). DOn’t know much about clinical trials so I can’t vouch for their veracity. They mostly seem to have small study cohorts so the statistics are a bit weak I suppose. Would be nice to see a Cochrane review of this?

    • Thanks for the reference Fred. I’ll check it out. I’m intrigued, though, how you could do a double-blind trial involving meditation. Wouldn’t the subjects know whether they’d been meditating or not?

  4. If boosting the immune system has raised all kinds of red flag, then why do Doctors “Boost” the immune system as soon as you are born with antibiotics? You have to remember we are all given shots to prevent disease as soon as we are born. It’s a fact that most of those immune boosters are actually made up of modified viruses themselves. So our bodies are being set up to “fail” in the later years of our life, because we have been exposed to many antibiotics, non nutritional fast foods that weaken the immune system. I would not throw out the baby with the bathwater.

    • Colloidal Silver4me,
      I suggest you consult a good reference to find out how the immune system really works. (You could try here, here or here). For a start, antibiotics have no connection with the immune system and they are not routinely administered to newborns. And as unhealthy as “non-nutritional fast foods” may be, the problem is not that they “weaken the immune system”.

  5. corrector permalink

    So, do you suggest vaccines are bad?

    • corrector,
      Can you please expand on your comment? I can’t see where it fits into the discussion. Where is there a suggestion that vaccines are bad?

      • corrector permalink

        Aren’t vaccines supposed to boost your immune system?

        • Not really. A vaccine allows the normal operation of the immune system to be activated in response to a particular disease, without the vaccinated person suffering from the disease itself. A specific vaccine will give you immunity to a specific disease. There is no suggestion of somehow “strengthening” the immune system, but simply a case of allowing it to operate normally without the accompanying risk of infection.

          • corrector permalink

            So what is the adjuvant in the vaccine for?

          • Of course the adjuvant enhances the immune response to the antigen in the vaccine, but it’s a bit far-fetched to regard this as “boosting” the immune system in the sense of this blog post, don’t you think?


    here’s the link to the meditation article mentioned above. it seems that here they used a response to a vaccine as a way to measure the strength of the participants immune system…? have I got that right? i found that interesting because i agree that the post is not really about vaccines, as they don’t claim to most the immune system on a general/global level but they are of course related to immunity, of the ability for the immune system to fight certain diseases, through having been ‘primed’…though previous exposure..

    • Thanks for the link, katephillips. Yes, I think you’re right in your assessment. As Fred suggested though, it’s not a particularly convincing study given the small sample size.

Trackbacks & Pingbacks

  1. Boosting the immune system–sorting science from myth
  2. Immune system myths – can we really boost it?

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