The immune system is complicated. Made up of a large network of cells, proteins and organs, it is the metaphorical last line of defence between your body and infections. So, with such an important role, you want to keep it safe.
But how do you do that? Like many other important parts of our bodies, there are plenty of supplements and products ready to boost your immune system to its highest function. But the problem is, your body doesn’t really need them. In fact, it is probably much better without.
The immune booster fallacy
Immunity-boosting vitamins are a somewhat confusing concept. In theory, the immune system doesn't need help. It is a finely oiled machine, which will operate healthily on its own if you are living a relatively healthy lifestyle.
In fact, the idea of boosting your immune system is somewhat vague. Boosting the number of immune cells or other similar cells in your body isn’t necessarily a good thing and can lead to more risks than benefits.
Just think of the immune system as a perfectly calibrated machine. It has been set up perfectly to do its job (as long as it is maintained, of course). If you try to make the machine work in overdrive, it could cause the machine to overheat or break.
The same can be said for the immune system. A so-called ‘boosted’ immune system is overactive, which could lead it to attack healthy cells (known as autoimmune disease).
“The immune system is very capable of taking care of itself under most circumstances. We don’t need to do anything to enhance its function as long as we lead a reasonably healthy lifestyle,” Dr Bobby Cherayil, the author of the book The Logic Of Immunity, told BBC Science Focus in an episode of the Instant Genius Podcast.
“This includes consumption of a healthy diet, appropriate amounts of sleep and exercise and avoiding potentially harmful behaviours such as smoking and frequent excessive use of alcohol.”
While the immune system can start to falter when our lifestyle slips, it doesn’t happen instantly, and in most cases, requires quite a dire situation for infection to start slipping in.
“If you have a very malnourished diet, or you are becoming severely deficient in the consumption of vitamins needed, it can have adverse effects on the immune system. But this has to be a very extreme state of deficiency,” Cherayil said.
The potential risk of vitamin supplements
If you live a healthy lifestyle already, eating a balanced diet, sleeping enough and exercising regularly, what is the harm in also taking supplements to boost your immune system?
For most, there is no real harm, more simply a lack of effect. The body can only absorb so much, and for healthy people taking additional vitamin supplements, a lot of that will be passed straight through the body and out through urine.
However, this is only the case for water-soluble vitamins. Vitamin A, D, E and K won’t pass straight through and excess levels can amount to a toxic supply of the body. Excess vitamin D, for example, can lead to vomiting and weakness and eventually, bone pain and kidney pain if left untreated.
Many immune-booster supplements fall into the category of ‘multivitamins’ – a term to cover supplements offering a range of vitamins and minerals in one tablet or capsule.
One major study linked multivitamins with a high-rate of placebo effects, with participants reporting feeling much healthier despite showing all of the same health stats as the control group.
In fact, when put through clinical tests, there were absolutely no differences in mental or physical health results between the two groups. However, those taking multivitamins believed that their use of said vitamins had made them healthier.
What's the harm? People taking multivitamins can believe they are covering all potential areas of their health with multivitamins, letting other areas such as a healthy diet slip.
However, on a longer scale, excessive consumption of vitamins is still a widely unknown area. While in most cases, there are no real negative effects, some studies have linked the use of multivitamins to increased risk of cancers, heart failure or cardiovascular problems.
Studies also show a raised risk with age. Research from the University of Minnesota examined data from more than 38,000 women around the age of 62, with those taking supplements having a 2.4 per cent increased risk of death.
This is still very much a growing area of study and not all research points to such an extreme result. One study, for example, found no associations between multivitamin use and mortality from all causes.
Vitamins do still serve a purpose… for some
If a healthy lifestyle is a better fix for your immune system, we should all simply forget about the supplements and work on our health, right…? Well, for the most part.
For the vast majority of people, a healthy lifestyle is all that is needed to keep the immune system in tip-top shape. But for some people, severe vitamin deficiencies need to be addressed.
More than 2 billion people in the world are deficient in key vitamins, and certain groups are more in need of a helping boost.
Vitamin supplements, including those that are related to the immune system, can be useful for those in stages of advanced age where chewing and swallowing become difficult. The same may go for pregnant people or those with digestive issues (in these cases, you should consult your doctor).
But ultimately the immune system is an incredibly advanced self-regulating machine. And, for the average person, it is working at full power. While an immune boosting supplement is unlikely to cause much harm, it is equally more likely to be, as they are often suggested, simply creating ‘expensive urine’.
About our expert, Bobby Cherayil
Cherayil is an associate professor of paediatrics at Harvard University and the author of the new book The Logic of Immunity. His areas of study include the immune system and its response to infection and inflammation.
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