Nurturing the immune system

It is becoming ever-clearer that a multi-pronged approach is the way to go in enhancing the immune system. The immune system comprises a varied network of proteins, cells and organs that must be strong enough to tackle invaders, while being sufficiently restrained to not target healthy cells or harmless molecules. There is often talk of “boosting” the immune system in itself, but in a literal sense that may be a very bad idea. We then run the risk of overreactions underlying allergies and autoimmune systems. The immune system requires assistance rather than supercharging.

Myths abound regarding warding off illnesses, such as a megadose of vitamin C to head off colds. It doesn’t. In days long gone, carrying posies out in the street to ward off bad air and illness was also the science of the day, but that probably didn’t work either. And with all the incorrect health information abounding on social media today it’s not always easy to sieve the wheat from the chaff.

So what is science telling us today? The first thing we need to look at is our microbiome. All our immune arsenal’s main cell types are influenced by the trillions of bacteria resident in our gut. Among their tasks is maintaining the integrity of the gut lining to prevent inflammation and leaks, while churning out beneficial chemicals including short-chain fatty acids that modify T-cells as a response to viruses such as HIV and influenza. A microbiome is best kept in prime condition by supplying it with microbial diversity with an abundance of whole foods along with at least 30 grammes of fibre a day. Other foods known to give the immune system a boost include sauerkraut and (preferably fresh) ginger, the latter triggering the release of cytokines that help manage immune responses.

We can then recruit probiotics into our immune armoury. These are living microorganisms we can eat or drink in fermented foods such as kimchi, kefir or natural yoghurt. During the covid-19 pandemic it was noted that those consuming such fare had milder covid symptoms than those taking zinc, garlic, vitamin C or nothing at all.

From the complexity of the microbiome we then turn to the relatively simply activity of gardening. Healthy soil is brimming with beneficial bacteria that are transferred directly from our hands to our gut. These bacteria are associated with improved immune health. Communities that farm manually have demonstrated to have more robust immune systems than industrialised farming cohorts. And indeed, while diet is a complex but powerful immune health modulator, exercise is a more straightforward bringer of immune health with a wealth of evidence showing that moderate exercise such as swimming or brisk walking helps by raising the number of circulating immune cells that are on the lookout for pathogens and rogue cells. Walking in a natural environment such as woodland also exposes us to good bacteria that are welcomed by our systems. Consistency is the key, though, as research indicates that after a couple of weeks without any exercise the immunity benefits thereof have been lost.

A study published in Nature also showed that our immune system can be influenced simply by how we think. Research has shown that merely anticipating illness causes brain changes that alter immune activity and mirror what happens when the body encounters a real infection, while long-term stress is deemed to be potentially the biggest threat to our immunity with the release of hormones such as cortisol that impair our signalling pathways. Mental disposition is apparently a factor too. It is not unheard of for 100-year-olds to be seen sitting around drinking or smoking. One reason is believed to be their great attitude to life.

So the message for a prime immune systems seems to be to go for the slow fixes, with nourishment of the microbiome using foods such as fermented foods, daily exercise and keep your stress in check.