Winter Immune Health Tips

Understanding Your Immune System 

The immune system is a complex system involving hundred of thousands of cells and relying on millions of interactions and orchestrated cell communications. You don’t want a revved up immune system and neither do you want a flaccid one. Think of your immune system as your internal army - it needs to be able to ‘fight a good fight’ for you if needed.

It may sound like common sense but some of the most powerful things that support a healthy immune system are a balanced diet, good quality sleep, regular exercise, stress management and vitamin and mineral supplementation.

The best diets are whole food plant based diets that incorporate lots of dark leafy greens, cruciferous vegetables, colourful fruits and nuts and seeds. These kinds of foods contain lots of vitamins, minerals, antioxidants, phytonutrients, fibre and prebiotics that all help keep the immune system nourished and fortified. The food we eat becomes the building blocks of the immune system so think of food as your cellular fuel - you want to be running on premium fuel. In the winter months in addition to healthy food choices everyone should take supplemental vitamin D because in the UK in the months from September to May the sunshine isn’t strong enough to provide all of our vitamin D requirements. Vitamin D is intricately linked to your immune health so it shouldn’t be overlooked, plus its almost impossible to eat your way to good vitamin D levels in the winter time. I also recommend supplemental vitamin C and zinc to help keep your white cell immunity strong and some probiotics if your gut health is compromised because the gut is an important player in immunity. It is thought that about 80% of immune tissue resides in the digestive tract so a healthy gut will feed a healthy immune system.

Exercise is wonderful therapy for the immune system. Who knew that the simple act of moving more could help fight infections?! There is now compelling evidence that links regular exercise with good immune and metabolic health, both very important as we battle the Covid pandemic and influenza season this winter. A 2009 scientific review published in the Journal Sport and Health Science found that regular exercise can improve your immune response, reduce inflammation and lower your risk of overall illness. Exercise works in a number of ways. Firstly it increases blood and lymph flow which means that immune cells move around the body at a higher rate after exercise and it also recruits highly specialised cells called Natural Killer cells to find potential pathogens and attack them. Natural Killer cells are also vital for protecting against cancer so it’s a double benefit for exercise. Exercise also helps to drive down cortisol which is our stress hormone. Reduced cortisol results in reduced systemic (whole body) inflammation and this consequently improves immune function. Exercise is also great therapy for low mood in the darker, winter months as it boost the body’s endorphins, natural mood elevating hormones. Mood elevation is related to better immune function so regular exercise is a WIN WIN for us all. Try to combine some cardio, strength training and restorative exercise (eg yoga/pilates) into a standard week as each one offers benefits to overall health and immunity.


Sleep is one of the body’s great restorative activities and good sleep is fundamental to immune function. Studies have shown that sleep deprivation can make you much more prone to illness. Good sleep and preservation of the circadian rhythm are strong mediators of immune activity. Sleep deprivation can make even a flu jab less effective, such is the power of sleep! Sleep seems particularly linked to good T cell immune activity. T cells are a type of white blood cell and they are part of the body’s first line of defence against toxins, viruses and bacteria so its very important to keep your T cells strong and resilient. Studies have shown that shift workers for example, who disturb their circadian rhythm on a regular basis and survive on less sleep, are more likely to get breast cancer due to melatonin suppression. Cancer occurs when the immune system fails to clear damaged cells so it stands to reason that those surviving on little sleep are more prone to many different kinds of illnesses. 

Your gut is home to trillions of micro-organisms all of which play a vital part in immune function and maintaining health. In fact there are so many microorganisms in the human gut that it is said we are only 10% human and 90% micro-organism. These gut bugs aren’t just hitching a free ride. They have actually co-evolved with us for millions of years and without them we wouldn’t survive. Although not visible to the naked eye, these tiny organisms steer virtually every conceivable aspect of human health and determine your level of health for life. Look after your gut buddies and they will look after you! The gut’s microorganisms thrive on fibre so a diet rich in fibre is hugely important. If your gut isn’t in great shape then improving your diet is the first thing to do. Fibre rich foods are vital for gut health and immune function. If you have taken a lot of antibiotics, alcohol, sugar or had a lot of stress in your life then its a good idea to replenish some of your beneficial bacteria with probiotic foods or supplements. Probiotic rich foods contain beneficial bacteria that can help to repopulate the gut. Search out foods like live yoghurt, kefir, kimchi, miso and tempeh or take a high strength probiotic supplement. Look for a probiotic with lots of different beneficial strains and large colony numbers for efficacy. Boosting the health of your gut will have huge benefit for your immune health. 

Vitamin D is one of the most important vitamins for the immune system and is a vitamin that most Brits are deficient in because we cannot make enough in the winter. It is thought that over 1 billion people in the world are low in Vitamin D which is of great public health concern. Emerging evidence is coming through all the time that suggests that those who have optimised levels of vitamin D suffer less with Covid as well as the common cold and flu. Vitamin D supplementation is a cheap and effective intervention and should be implemented across the entire population. Vitamin D receptors are found all over the body helping to boost the body’s innate immunity. Innate immunity is the body’s first line of immune defence involving physical, chemical and cellular defences against pathogens. You can get your vitamin D levels checked with your doctor and then supplement accordingly. If you cannot get a check its pretty safe to presume that you will be on the low side in the winter months if you live in the UK and you haven’t been on a recent sunny holiday!


Winter Immune Tips:

Start your day with a seasonal immune boosting smoothie with things like mixed berries, avocado, kale, banana, vanilla, mint and plant milks. Try to eat seasonal vegetables that are fresh and sustainable. Think of food as your cellular fuel and invest in your food choices knowing that the food that you eat becomes the fuel that runs your body. Go organic wherever possible, avoid cheap ‘gas station’ convenience foods with long shelf lives and try to eat foods in their most natural form. This way the foods you eat will be full of natural goodness and micronutrients that will propel your immune health forward positively. 

Get out in the fresh air daily - daily outdoor exercise is a great way to keep fit but also to get away from central heating and recirculating air in the winter. Deep breathing helps to keep the lungs optimised and a brisk walk or jog stimulates the circulation and keeps the immune cells moving around the body. Humans need regular exposure to sunlight to help regulate the circadian rhythms and to keep mentally healthy. So a winter walk is the ideal way of getting some natural sunlight to help keep your mood elevated and your circadian rhythm in sync. The other thing you can do is to get outdoors and use your body for exercises like squats, lunges, burpees, planks, pull-ups and press-ups all of which can be done outdoors. We know that all kinds of exercise benefits the immune system so whatever you can do is a positive. 


Take an Immune supplement with vitamin D, vitamin C and zinc to keep your immune cells functioning at their best. Supplements don’t replace the need for a healthy balanced diet but they can help bridge any deficits. You don’t want megadoses of these vitamins but neither do you want to be deficient in the immune systems micronutrients through the winter months. Vitamin D, Vitamin C and Zinc are the big players of immune health and are important building blocks of immune cells. Try ZENii Immune Defence for an intelligent immune supplement this winter.

Immune Defence