It’s starting to feel pretty chilly out there, which means flu season is just around the corner. Around 10-25% of us get the flu each year, with most cases occurring in January and February. The flu season runs all the way from November to April though, and this year it’s more important than ever to take steps to steer clear of the flu and other infections.
So, how can you support immune function this autumn and winter and cut your risk of catching a cold or the flu? To keep your immune system in good shape, it’s important to understand how it works to stave off the viruses, parasites, bacteria, and fungi that cause infection.
How your immune system works
The immune system has two main branches: acquired immunity and innate immunity.
Acquired immunity is the type of protection we get from having previously been exposed to a pathogen. This can be from vaccination or previous infection. Having learnt how to defeat a virus or bacteria before, the body is ready to jump into action and create specific antibodies if it encounters that same pathogen again. This is why, if you’ve already had chicken pox, or been vaccinated against measles, you don’t normally get these infections again.
Unfortunately, acquired immunity isn’t all that helpful when it comes to the flu and the common cold. There are hundreds of different cold viruses and many flu viruses, with strains mutating throughout the year, which is why vaccine researchers try diligently to create flu vaccines that target the most common circulating strains of the influenza every year (and why getting the vaccine every year is so important!).
Fortunately, acquired immunity is only one branch of the immune system. We also have innate immunity to help respond to potential infection. In fact, this is the first line of defence against potential pathogens and involves specialised white blood cells that sound the alarm about harmful microorganisms and move in for the kill.
Phagocytes are one type of white blood cell that literally eats invading pathogens. In Greek, ‘phago’ means to eat. Other immune system cells include Natural Killer cells, neutrophils, dendritic cells, and mast cells.
How to support your immune system
The cells that make up your immune system rely on certain inputs in order to function properly. They are also susceptible to a variety of nutritional deficits and lifestyle factors.
For instance, if you’re feeling a lot of stress, especially over a long period of time, the immune system is less equipped to fight off infection. Elevated levels of the stress hormone cortisol, and the fight or flight hormone adrenaline, can actively suppress the activity of innate immune system cells, for example. This is why you’re more likely to catch a cold if you’re feeling perpetually frazzled.
Stress also means you’re more likely to use coping mechanisms that also compromise immune function, such as smoking and drinking more alcohol. You might also turn to unhealthy comfort food instead of nutritious food that provides your body with zinc, vitamin C, and other essential nutrients.
Feeling anxious and stressed often leads to problems with sleep and focus. In turn, this could mean you increase your intake of caffeine to stay alert. Feeling sluggish and tired can also mean you exercise less. Again, all of these can inhibit proper immune function.
It’s not hard to see, then, the steps you can take today to support immune function. As a quick to-do list, here’s your natural prescription for immune health:
- Take a bath, practice yoga, meditate, read a good book, or find another healthy way to relax
- Practice good sleep hygiene – use blackout curtains, have a set bedtime, avoid screens before bed, keep your bedroom a little cooler than the rest of the house, get up at the same time every day. Immune system cells are less active after 11 pm, so get to bed early!
- Stay hydrated – ideally with non-caffeinated, non-sugary drinks. Use herbal teas such as chamomile to hydrate and calm feelings of anxiousness or valerian to support sleep. Staying hydrated also means mucus membranes are less susceptible to colonisation by pathogens.
- Go for a bike ride or take a walk - a stroll around the neighbourhood is a great way to unwind, get the blood flowing, and support mental and physical health – say hi to a neighbour from a distance!
- Eat a balanced diet full of fruits, veggies, healthy wholegrains, nuts, seeds, beans, and pulses to make sure you’re topped up with vitamin C, zinc, B vitamins, and other immune-supportive nutrients
- Take a vitamin D supplement – From October to April it’s hard if not impossible for us to make the sunshine vitamin from sun exposure in the UK, which is why most doctors now recommend everyone, from infancy onwards, takes a vitamin D supplement at least in winter if not all year round
- Mask up, wash your hands, use hand sanitiser, and keep your distance – following public health protocols for the pandemic can also help cut your risk of infection with the common cold and flu, as well as reducing the risk that you spread infection to others if you’re asymptomatic
- Enlist the help of probiotics – there are more beneficial bacteria cells in our bodies than there are our own cells, so it makes sense to help them help you. Probiotics like Lactobacillus rhamnosus and others are well regarded for helping support immune function, in addition to keeping pathogenic bacteria and other microorganisms in check.