Digestive Health Exercise Guest Writer Immune Support Nutrition

Top tips to look after your immune system through winter

Dr Ruth Cammish has been an NHS GP for over ten years.  She is passionate about lifestyle medicine and is the British Society of Lifestyle Medicine Regional Director for Manchester.  Her own experiences as a patient with severe eczema has shaped the way she looks at her own health; becoming interested in gut health, the immune system and holistic care.

The dark nights are upon us, the leaves are turning and it’s time to dust off that cosy coat. The season is busy, and we want to keep as healthy as we can to enjoy it.  Immune-boosting supplements line the shelves and it’s tempting to reach for them to ward off winter infections.

So, I ask…do these supplements work and what can we do to keep our immune system working well this winter?

Basics first – the marvellous immune system; our first line of defence, responsible for healing, repair and preventing infections. This complex network constantly monitors the body and acts quickly to protect us. It’s found mainly in our blood, thymus gland and in the lymphatic system which carries infection-fighting cells around our body. 70% of these immune cells are found in our large intestine, so having a balanced gut is essential.

Immunity can be affected by alcohol, smoking, chronic stress and poor nutrition. It changes as we age, with our thymus gland shrinking and producing less infection busting cells.

Why do we get unwell more often in winter?

We are more prone to infections in winter as we tend to spend more time indoors and in closer proximity to each other, which allows bugs to spread. Cold air is drier so when we sneeze or cough, the cold virus remains in the air for longer.

What changes could you make to stay well over the colder months?

1. Eat colourful food and plenty of fibre

A strong immune system needs a wide range of nutrients from our diet. The building blocks are protein, fibre, fat and micronutrients like iron, zinc, omega 3, vitamins A, C and D. Phytonutrients and polyphenols found in fruit and vegetables, red wine and dark chocolate, are anti-inflammatory. These key nutrients are plentiful in a varied, colourful, wholefoods diet but having extra from supplements won’t help the immune system work any better.

All of these foods are digested by our gut bacteria, producing nutrients needed to balance immune responses [1]. Fibre has a key role in feeding them, acting as a fertiliser to encourage a range of bacteria to grow. It’s a crucial part of a diverse microbiome and we need to eat for 30g of fibre every day [7]. Aim for 30 different plant-based foods each week and mix it up, our gut bugs love diversity.

2. Supplement vitamin D

The lack of sunlight means our body can’t produce enough vitamin D.  Although a small amount can be found in oily fish and fortified foods, most of us need an extra boost in winter from supplementation. The sunshine vitamin promotes bone health, but low levels leave us more susceptible to infection [5].

3. Keep moving

While very intense exercise is linked to increased risk of infections, regular movement is a key part of keeping healthy. It helps the lymph move round the body so it’s ready to spot infections and the endorphins boost our white blood cells. The recommended 150 minutes a week is a great aim, but even 10 minutes of brisk walking a day has major health benefits, including making us happier.

4. Wash your hands

Spending more time in the warm indoors makes the perfect environment for ‘bad’ bugs to thrive and spread. Hand washing is an easy way we can reduce the chance of picking one up. Be that soap and water, or alcohol hand gel, drying hands completely is vital as damp hands are up to 1000 times more likely to spread bacteria [2].

5. Get vaccinated

Flu vaccination is available on the NHS to protect at-risk adults and children from flu and its complications. Although it isn’t 100% effective, if you do catch flu following the vaccine, it’s likely to be milder and settle quicker. Check the NHS website to see if you are eligible.

6. Manage your stress

High cortisol released in chronic stress directly affects the way the immune system works. When the body is in constant ‘fight or flight’ mode, it prioritises survival rather than rest and repair. The run-up to Christmas often leaves us frazzled and at risk of being hit by a bug or two. Allow yourself downtime, evenings for self-care and connecting with others for emotional support. Meditation and deep breathing are known to stimulate a sluggish lymphatic system.

7. Sleep soundly

Another way our body restores itself is sleep and only 1/3 of us get the recommended 7-8 hours. Sleep deprivation decreases infection-fighting cells and has been shown to reduce the effectiveness of the flu vaccination [3,6]. Try to get natural light exposure in the day to help set your body clock, avoid caffeine after midday, have a consistent sleep and wake time, wind down at least half an hour before bed with no blue light from screens and avoid salty, heavy meals in the evening [4].

Winter cold tips

If you do succumb to a winter bug, listen to your body’s need to rest and recuperate. Drink plenty of fluids, have a duvet day and sleep. You’ll be able to bounce back faster if your body is well-rested. Avoid antibiotics where possible as they are ineffective against viral illnesses and also reduce the good bacteria in the gut.

How about the old wives’ tale of vitamin C to cure a cold? Unfortunately, the evidence isn’t there, although some studies showed a slight reduction length of a cold but only by 12 hours! Much better to have a diet rich in vitamin C all year round [8]. Similar results were seen with zinc taken within 24 hours of a cold but with 2 days less of symptoms in healthy adults [9].

Although our immune system is complicated and there’s no magic wand to warding off bugs; small lifestyle changes ensure you’re in the best form for winter.  Eat the rainbow, sleep, keep an eye on your stress levels and move every day; your body will thank you for it.


References

[1] A Valdes, J Walter, T Spector. (2018). Role of the gut microbiota in nutrition and health

[2] D Patrick, G Findon, & T Miller. (1997). Residual moisture determines the level of touch-contact associated bacterial transfer following hand washing. Epidemiology & Infection

[3] M Irwin (2002). Effects of sleep and sleep loss on immunity and cytokines. Brain, behaviour and immunity

[4] G Egger. (2017). Lifestyle medicine, lifestyle, the environment and preventive medicine in health and disease, Academic Press, 3rd

[5] C Aranow (2011). Vitamin D and the immune system. J Investig Med

[6] D Taylor, K Kelly, M Lohut (2017). Is insomnia a risk factor for decreased influenza vaccine response. Behav Sleep Med

[7] PD Schley (2002). The immune-enhancing effects of dietary fibre and prebiotics

[8] H Hemila, E Chalker (2013). Vitamin C for preventing and treating the common cold Cochrane Database Syst Rev

[9] M Singh, R Das (2013). Zinc for the common cold. Cochrane Database Syst Rev 18(6)