It tends to be around this time of year, when the temperature dips and we realise we’re rapidly approaching cold and flu season, that we collectively get curious about the condition of our immune systems. We sift through memories to try and calculate the most recent occurrence of sickness, and refresh stores of multivitamin supplements on autopilot in an attempt to “boost” our immune systems.

The immune system, of course, is critically important – it fights noxious substances from external and internal sources to protect your body from harm, so it makes complete sense that you instinctively want to keep it in tip top condition. But, with so much conflicting information, it’s hard to tell the facts from the fluff when it comes to supporting your immune system.

To get clear on what can really be beneficial for your immune system in winter, we spoke to Renee McGregor, sports dietician and Women’s Health Collective expert.

How can I protect my immune system in winter?

According to NICE, UK adults experience, on average, 2-3 colds per year – an illness that’s much more prevalent here during the winter months. Last year, researchers explored a new theory on why we get more colds in winter: that one of the immune responses may be less effective in cooler climes.

A study, which looked into the defence mechanism in the nasal cavity, found that a specific immune response – where, at the detection of assumed harmful bacteria, the nose releases extracellular vesicles; a spray that “swarms, bind and kills bacteria at the point of inhalation” – may be reduced in colder temperatures.

That said, there’s another very simple explanation for the recurring colds. ‘Generally, we get sicker during the winter months as we spend more time indoors in close proximity with each other,’ McGregor explains. ‘In addition, having our heating on means that all the viruses that are around can all be transmitted a lot easier than during the warmer months.’

So, aside from clearing your calendar until spring arrives, what can you do to reduce your chances of catching a cold?

Truth is: research tells us the most effective way to “boost” your immune system is through vaccination. Claims that supplements, and such, can strengthen your immune system are scientifically unfounded. According to McGregor, however, there are ways that you can support your immune system year-round.

‘Too-heavy exercise, poor sleep, stress, under-eating and dehydration can all depress your immune system so it’s about ensuring good practices,’ she urges. Sufficient sleep and fuelling your exercise well are among the habits she highly recommends for pursuing optimal health. ‘Also, listening to our body and not pushing it when you are tired and developing practices, such as mindfulness, that can help to manage stress are important.’ So too, she says, is staying hydrated. ‘Saliva is your first line of defence, thus, staying hydrated means you can maintain good saliva production.’

While supplements claiming to strengthen your immune system aren’t worth your cash, vitamins and minerals are important for overall health. The NHS advises everyone to consider taking a vitamin D supplement during autumn and winter. McGregor suggests taking a look at your probiotic intake, too. ‘A 12-week course of probiotics is shown to support your respiratory tract infection, especially in those that are physically active,’ she says. She also recommends having a varied and balanced diet with sufficient whole grains and plenty of colours.

Finally, being conscious of hygiene by washing your hands often and avoiding touching your face, especially when out and about, can help to reduce your chances of coming down with a cold – as while some germs are airborne, others can be picked up from contaminated surfaces.