The immune system and immunity overall is a common talking point in health and fitness circles. This is even more the case presently, gripped as we are by a global pandemic with novel coronavirus COVID-19. Though there is plenty of great, well-researched information about immunity already available online, with more being created daily – there is a vocal minority taking advantage of the situation to self promote, push their own agendas or make money. We want to set the record straight on common immunity myths once and for all, giving the definitive verdict on which myths there is truth to, and which deserve to be forgotten.

Myth 1: “I can boost the immune system with X”

A particularly pervasive myth, but a myth nonetheless. The notion of “boosting” the immune system is often used to trick people into thinking that they will be protected against disease or illness by taking a particular supplement, or course of several supplements. First of all, there is no evidence to date of any form of intervention being effective in preventing or treating COVID-19.

Secondly, the only evidence-based way of delivering a similar effect to “boosting” – i.e. making our immune system work above its normal capacity – is with vaccination. Even then, the vaccine needs to be rigorously tested to prove its efficacy and safety beyond all doubt. Vaccines provide our bodies with a weakened version of a specific virus, giving the body more time than it would have otherwise to prepare antibodies to fight that instance of the virus, and every instance of it from that point onwards.

Finally, though diet, lifestyle and psychology do play a role in immunity – they can only detract from our immunity with poor diet, an inactive lifestyle and so on. The more we can support our immunity through these three elements, the better our immune system will function. With the right combination of diet, lifestyle and psychology, we can reach maximum efficiency in our immune system, but can never “boost” to exceed that point.

Myth 2: “Diet Y is the best way to boost the immune system”

Every year brings with it at least one flavour of the month diet, sometimes several. As with the previous myth, there is no strong evidence to suggest that a specific diet like the ketogenic, plant-based or carnivorous diets is better for immunity than any other diet plan.

For a diet to effectively support immunity, it needs to tick several boxes. It first needs to provide us with enough calories to maintain healthy body weight and fat levels (a factor that is widely undervalued in its ability to keep us healthy). At the same time, a diet needs to provide us with all essential nutrients in adequate quantities. If these boxes are ticked, it won’t provide us with food or nutrients that actively hinder the functioning of our immune system.

No matter what, it is important to note that any dietary recommendations vary greatly person to person. Age, our ability to consistently adhere to a diet, activity levels, health status and so on all play a role in how effective a given diet can be in supporting immunity.

There is no best diet for immunity, therefore. The so-called “best” diet for you varies greatly, and is likely to include components of several diet types, not just one – forming the kind of balanced diet discussed in an earlier post.

Myth 3: “Alternative therapy is the best way to boost immunity”

As mentioned earlier, the only evidence-based way to “boost” immunity is with vaccination. There is no evidence to suggest that acupuncture, homeopathy or chiropractics have any impact on the immune system. The myth these therapies are helpful is particularly harmful because it has caused individuals to forgo vaccines in favour of alternative therapy. In fact, the World Health Organisation (WHO) have argued that vaccine hesitancy is one of the biggest global threats we face today. Vaccines are believed to prevent 2-3 million deaths annually, and the WHO estimate that 1.5 million more deaths would be avoided if global coverage of vaccines improved.

Macedo, de Faria and Ghezzi (2019) reviewed the impact of immune system misinformation, finding that 50% of the US population use supplements to support immunity – despite the lack of evidence supporting the use of any of them. They also found that in a cohort of 9,000 American children, any form of exposure to alternative therapy or medicine typically led to reduced uptake of vaccination when it was offered. Similar results were reported in a sample of 9,000 Australian women, too.

The danger of promoting alternative therapies is very real, potentially contributing to millions of deaths each year – if the WHO’s estimates are correct. A vocal minority are wrong to distrust vaccinations, and any misinformation around vaccinations should be immediately discounted to improve global health – with or without the global pandemic we are facing.