The Doctor’s Kitchen - Eat to Beat Illness: A simple way to cook and live the healthiest, happiest life. Dr . Rupy Aujla

for a great way of using more quality fats.

      + Fibre An effective strategy to improve our immune system would be anything that helps our gut environment; specialised prebiotic fibres including chicory, endive, Jerusalem artichoke and garlic provide your microbes with a source of food. When digested, they’re able to make a fatty acid chemical called butyrate which helps maintain the lining of the gut wall.¹⁴⁹ A well-fed microbiota is better equipped to carry out its immune-modulating role of reducing inflammation and preventing pathogenic microbes from colonising in the gut, causing ill health.

      + Herbs and spices A variety of vegetables, like the colourful ingredients described above, also provide a fantastic food source for the microbes and there is also a rationale for using plentiful herbs and spices. Ginger, turmeric, fennel, and some botanicals like peppermint may have a role in immune support as they have been shown in some small studies to reduce gut inflammation.¹⁵⁰ I think regularly including herbs and spices in our food for a culinary as well as functional purpose is an important aspect of our diets that we should embrace. Try the Ras el Hanout (see here) or the Laksa Paste (see here) for ideas.

      There are some specific botanicals and herbs that have shown ‘immune modulating’ capacity, in that they may stimulate the production of cells of the immune system.¹⁵¹ There is also a tradition of using different herbs for immune support across many cultures, including elderberry, Echinacea, mushroom varieties and probiotics. However, I would rather we focus on accessible diet and lifestyle aspects that serve to build your immune reserve rather than relying on immune-modulating plants for general sustenance. Improving your lifestyle and diet are much more powerful strategies than relying on a special flower or fungi for support.

      LIFESTYLE 360

      Nutrition has a huge role in maintaining robust and balanced immunity, but if there was any system that exemplifies why total coordination of lifestyle factors, such as exercise and sleep, is necessary for universal functioning, your immune system is the poster boy. By harnessing the power of a variety of lifestyle factors, you can greatly enhance your metabolic energy and the ability of your immune system to perform at its peak. It will not only improve your resilience to common viruses and pathogens, but also aid inflammation balance under the control of immune cells.

      + Exercise For everyone there is an exercise sweet spot. Regular moderate exercise has been shown to universally benefit immunity. Aerobic exercise actually encourages your body to be more resilient to stressors and therefore has an overall benefit, despite the short-term effects of exercise being inflammatory.¹⁵² Aerobic exercise can actually improve your mitochondrial function which may also be why regular exercise builds a resilient immune system.^{153, 154}

      Persistent over-training, however, is associated with reduced immune reserve. There are recognised health risks of putting high amounts of strain on your body by over-exercising, that researchers have observed in endurance athletes like cyclists.¹⁵⁵ A balance of training is what we should be aiming to achieve and there are specific types of exercises that may be particularly good for immune health.

      + Yoga Described as both a mindfulness technique as well as a form of exercise, recent studies on yoga have examined a fascinating effect on immune cells.¹⁵⁶ Researchers have demonstrated that yoga practices can impact the expression of genes to one that positively improves immune cell function. Similar effects have been shown with other practices such as Qi Gong and Tai Chi.¹²⁰ Combined with the physical benefits of the exercise, yoga could be one of the best all-round immune health promoting activities we know of. The best advice I have is to mix it up. I have developed my own yoga routine from watching online yoga sessions that are very accessible and easy to follow, as well as attending classes now and again to get some pointers. But I would also encourage HIIT (high intensity interval training) sessions, too, to improve aerobic capacity, as well as endurance training such as cycling and swimming for their additional benefits.

      + Meditation The gradual deterioration of our immune capability as we age, known as immunosenescence, may be closely related to both psychological distress and stress hormones.¹⁵⁷ It would stand to reason that techniques to reduce stress effects may be beneficial from an immune perspective. Combined with the many positive effects of mind–body interventions, practices such as deep breathing, transcendental meditation or simple walks in nature are a no-brainer for me to advise. I was pleased to read a paper about the positive effect of walking in nature, specifically on cells of the immune system.¹⁵⁸ So perhaps the most immune-system-enhancing of activities could be a yoga session in a park followed by deep breathing in natural sunlight. And this brings me nicely onto the subject of vitamin D.

      + Vitamin D More than a vitamin, vitamin D acts as a master hormone that regulates a multitude of genes involved in a huge number of processes. Beyond its well-recognised involvement in bone health and calcium regulation, vitamin D has a very important role in immune health.^{159, 160} In both the initial ‘innate’ response to infections and the more specific ‘adaptive’ responses, scientists are researching the role of vitamin D and its importance to auto-immune conditions. There are very few sources of vitamin D in the diet and thus medical practitioners in the UK have taken to recommending vitamin D for the whole population during winter months and for those with darker skin colours. The best advice is to get adequate sun exposure outdoors, have regular tests by your GP if you’re at risk and take a supplement during the darker months of September to March in the UK.

      + Sleep deprivation It will come as no surprise to many people that sleep deprivation drastically lowers a person’s immunity. Your immune system is very likely to be regulated by routine and the sleep–wake cycles which influence all other cells in your body operating on a rough 24-hour cycle.¹⁶¹ This is why sleep is integral to a healthy immune system. As a GP, I’ve lost count of the number of people turning up on a Monday suffering acute tonsillitis directly attributable to late nights at the weekend or travel. But this is just the tip of the iceberg. Persistent sleep loss significantly disrupts your immune system, increasing inflammation which drastically raises the risk of chronic illnesses like heart disease, Type 2 diabetes and even cancer. As you can probably appreciate by now, these are all conditions related to an ill-performing immune system. Achieving 7–9 hours of sleep a night could be considered one of the most potent therapies for improving ones’ immune system and it’s definitely on my prescription pad.

      To sum up diet and lifestyle strategies to improve immune health we simply need to remember a few facts: gut health is exceptionally important; there are well-recognised detrimental effects of a western diet on immune health¹⁶² (high in sugar, refined carbohydrates, low in fibre and lacking in micronutrients); certain micronutrients are critical for the adequate functioning of our immune cells; and the importance of supporting our mitochondria cannot be underestimated. Although this may sound complicated, the reality is that these additions to your diet and routine are accessible and straightforward. I’m confident that it is achievable for you as it is for many of my patients and my recipes will set you on the right path.

       Eat to beat

       Cancer

      

      This was by far the most difficult chapter to write. Not least because it is a complicated topic to tackle, but also because it is an emotive