With winter just around the corner, it’s important that we look at how we can support and maintain our health for the whole family. According to the Institute for Optimum Nutrition (ION), a London-based leading provider of training in nutritional therapy, supporting our immune health in the long-term can help to build up our resilience against future infections.

There are several dietary and lifestyle changes that may strengthen our body’s natural defences, including managing stress, getting enough sleep and good nutrition. Paula Werrett, Head of Undergraduate Provision at ION and a BANT-registered nutritional therapy practitioner, shares her top tips to see us through the winter months:

1. Limit ultra-processed food – Poor nutrition has been found to increase the risk of infection and can lead to compromised immunity, so limit sugary, processed snacks and reduce your reliance on ready meals. Selected nutrients play a fundamental role in how well our immune system works. It is much easier to fit these nutrients into meals if you’re not filling up with empty calories (i.e. foods that are low in nutrients) every few hours.

2. Eat a rainbow – For a well-functioning immune system, micronutrients should include vitamins A, C, D, E, B2, B6 and B12 as well as folic acid, iron, selenium and zinc. Replenish these by eating the rainbow – a range of vegetables and fruits with different colours – over the course of the week. This also feeds helpful bacteria in the gut, which play a fundamental part in regulating a healthy immune response and ensuring the body can recognise invaders.

3. Super vitamins – Infections significantly deplete the body’s vitamin C stores. Sugar also competes with vitamin C for uptake into cells, so instead of an afternoon snack consisting of a sweet treat, go for citrus fruit or other vitamin C-rich foods such as berries, kiwi, mango and sweet peppers in addition to eating your greens at meal times. You will instantly add more immune-supporting vitamins, minerals and antioxidants into your diet while cutting out the foods that can leave you feeling lethargic an hour later.

Studies have also indicated that oral vitamin C (2-8g/day) may reduce the incidence and duration of respiratory infections. However, ION always recommends talking to a BANT-registered nutritional therapy practitioner or a GP before supplementing.

4. Vitamin D – Vitamin D deficiency is most likely to be a problem during winter months, since we absorb most of what we need through the skin over summer. It is thought that vitamin D deficiency may be associated with sub-optimal immune function and an increased risk of infection, with studies now linking vitamin D deficiency to the severity of COVID-19.

Good food sources include oily fish such as mackerel, sardines and salmon, as well as egg yolks. Vegetarians and vegans can get vitamin D through some mushrooms and some fortified foods such as plant milks or nutritional yeast.

The NHS also recommends everyone to supplement with 10 micrograms of vitamin D every day throughout the winter months. However, studies point towards upwards of 100 micrograms being most optimal for human health.

5. Reduce stress – Chronically raised levels of the stress hormone cortisol can result in the immune system becoming resistant to the stress response. Swollen glands, a sore throat and aching limbs can all be signs that the body is trying hard to cope, and a good indicator to take time to rest and relax. Gentle exercise such as meditation, yoga or walking can help you to do this.

6. Prioritise sleep – Studies have shown that sufficient sleep helps the immune system to work well, with chronic sleep deprivation an independent risk factor for impaired immunity. It’s important to prioritise quality sleep by eating meals at least a couple of hours before bedtime. Avoiding technology close to bedtime and winding down with a bath or listening to some music can help to aid sleep.