And, if possible is that something one should try?
Now a days there are a multitude of products out there that claim to “boost your immune system”. Do they work? More importantly, can the immune system be “boosted” at all? Would such a “boost” be a desirable thing ?
In a recent episode of Skeptoid, Brian Dunning tackled this very issue. The podcast transcript can be read here. Brian points out one very important thing to keep in mind: it is wrong to think of the immune system as something that gets better the “stronger” it gets. The immune system can go haywire and start attacking our bodies, so when it comes to immunity you are looking for the right balance, not necessarily an increase in brute force. That is what vaccinations achieve, they strengthen the immune response to specific things. However, that is not the claim that these products that supposedly will “boost your immune system” make; they generally do not claim that the specific product will help increase the immune response to one specific disease; in fact, they can’t make those claims which is the reason for hiding behind the very vague and general boosting claim.
The immune system in a nutshell
So just what is the immune system? According to the National Institute of Allergies and Infectious Diseases :
The immune system is a network of cells, tissues, and organs that work together to defend the body against attacks by “foreign” invaders. These are primarily microbes—tiny organisms such as bacteria, parasites, and fungi that can cause infections. Viruses also cause infections, but are too primitive to be classified as living organisms. The human body provides an ideal environment for many microbes. It is the immune system’s job to keep them out or, failing that, to seek out and destroy them.
The immune system is not solely an internal thing; skin, mucus, saliva those are the first lines of defense and are part of what is know as the innate, or natural, immunity which we are born with. I am not sure if these products mean to boost the innate system or not, however I’m not convinced that boosted skin or mucus production is a desirable outcome.
Besides the innate immunity we also have adaptive and passive immunity. Adaptive (or active) immunity develops throughout our lives as people are exposed to diseases or immunized against diseases through vaccination. Passive immunity is “borrowed” from another source and it lasts for a short time ( for example the antibodies in a mother’s breast milk provide a baby with temporary immunity to diseases the mother has been exposed to).
Innate immunity is what it is, and there’s not much that can be done to “boost” that part; passive immunity is a temporary thing which by definition can’t last long, so “boosting” it doesn’t make much sense. That leaves us with adaptive immunity: all claims of “boosting” immunity must necessarily refer to the adaptive portion. So how can adaptive immunity be improved, or boosted? To understand that, we need to understand how it works.
Basically, the immune system classifies everything it comes into contact with as “self” and “non-self” or “foreign”; its job is to ignore the self cells and to attack and destroy all foreign cells. Anything that can trigger this immune response is called an antigen. An antigen can be a microbe such as a virus, or a part of a microbe such as a molecule. Tissues or cells from another person (except an identical twin) also act as foreign antigens. This explains why tissue transplants may be rejected and why many recipients of transplanted organs have to take immunosuppressant drugs (drugs that suppress the immune response). These foreign cells are attacked, and hopefully destroyed, by white blood cells, called T cells and B cells. This site explains the functions of such cells in a very intuitive and easy to understand way:
B lymphocytes are like the body’s military intelligence system, seeking out their targets and sending defenses to lock onto them. T cells are like the soldiers, destroying the invaders that the intelligence system has identified.
In a nutshell when an antigen is introduced in the body, the B cells are “notified”; they produce antibodies which attach themselves to the antigen. The antibodies themselves do not destroy the antigen, they simply attach to it and act as beacons, or tags, which are in turn recognized by the T cells. The T cells either by themselves, or by invoking the help of other types of cells, attack the antigen, and hopefully destroy it. Any type of boosting of the immune system has to happen somewhere along this chain of events.
To boost or not to boost?
I guess, depending on how loose one wants to play with the definition of the word “boost”, all vaccinations can be said to boost the immune system, but not in the general way the over the counter potions claim. Vaccines introduce an antigen in the body, in a form that cannot, or is highly unlikely to, cause disease in order to train the immune system and “trick” it into forming the necessary antibodies so that next time the real antigen infects the body, the T cells will know how and where to attack.
Similarly, becoming sick will also boost your immune system, in similar fashion to the vaccination process, but with much more pain, suffering and death involved. That is why we prefer boosting our immune system with vaccines as opposed to disease.
Any other claims of “boosting” the immune system are not based on science. Without introducing the antigen there is no way a drink or capsule can do anything to boost the immune system. Next time someone makes this claim to you, just ask them which disease specifically does the potion work for? Measles? Mumps? Varicella? Whooping Cough? If they pick any, or say all, ask them about the scientific evidence supporting that claim. If they produce any, then all the better: we just found a new way to combat disease. However, more likely than not, they will not be pinned down on any specifics, will not provide any evidence, and will keep hiding behind meaningless phrases such as “promoting a healthy immune system.”
So, can the immune system be boosted? Absolutely, either via vaccines (the saffer option) or actual disease (the worst option). Be wary of any products claiming to either “boost the immune system” or to “promote a healthy immune system” or any similar wishy-washy claim.
Don’t be fooled. Learn to distinguish scientific truth from sciency sounding advertising.