When everything is going to plan, our immune system does a terrific job in protecting us without us even noticing. It fends off harmful agents – such as bacteria, viruses, parasites, pollutants and allergens – all the time, using a variety of different mechanisms.
The first line of defence are barriers: the skin, saliva, a mucous lining along the respiratory system and digestive tract as well as stomach acid do a good job keeping invaders out or destroying those we might ingest. A healthy gut also produces universal antibodies, which act like bouncers and check out the contents of the intestine to make sure that only the good stuff is absorbed. Undesirables are denied entry and passed along for excretion.
Pathogens that do manage to invade the tissues or even the blood stream will be attacked by white blood cells, which either destroy them or cling on to them to prevent them from doing harm. Any resulting debris is swept out via the lymphatic system. Fever, too, is a symptom of your immune system fighting: Heat can destroy microbes, and that’s what your body is trying to do so it serves a valuable purpose, but if it persists for more than two days, seek medical help.
A healthy immune system works incredibly well, but what we eat and drink can strengthen or weaken it, so here are my tips on how to build up your defences:
Avoid sugar and refined carbohydrates
Sugar is an immune suppressant, affecting the immune system in different ways, either directly or via the stimulation of insulin secretion. “Refined carbohydrates” are white flour products, such as bread, bagels, pitta and white pasta, or white rice. Although they might not taste sweet, they are very quickly turned into sugar in the process of digestion and therefore have the same effect.
Your mucous membranes need to stay hydrated. If they dry out, their barrier function is impaired. Moreover, fluids help the lymphatic system to flush out waste. Avoid alcohol, tea and coffee. Go for herbal teas, green tea or water instead. Lemon is rich in vitamin C and ginger has antiviral properties, tea made with those two is not only great to fight colds or flu, but also very tasty.
To strengthen your defences, you could have a daily dose of fresh (!), homemade juice. If you have a juicer, try Jason Vale’s delicious Lemon and Ginger Zinger.
Garlic and Onions
Garlic and onions, too, have anti-viral and anti-bacterial properties, so use them liberally, cooked or raw.
Keep your diet ‘clean’
Stay away from junk foods, take-aways and ready meals. If there are more than five ingredients listed, put it back on the shelf. Just eat natural foods as you would find on a farmers market or around the edges of the supermarket: fresh fruit and veg, fish, chicken, beans and pulses, brown rice or quinoa, nuts and seeds.
If you already have a cold, it is best to avoid dairy as it is mucus forming. Cheese – especially melted cheese – and meat are hard to digest, so you may want to give your body a break during recovery.
Have lots of fresh fruit and vegetables to increase your intake of vitamin C. However, avoid orange juice and fruit juices in general as they are high in sugar. Eat an orange instead. Citrus fruit might be the most famous for vitamin C, but really all fresh fruit and veg contain it. Cabbage, kale, spring greens, and broccoli are excellent choices.
Of course there are more ways to protect yourself, which are not food related:
Wash your hands regularly. The most likely way to catch a cold or flu virus is via your hands. You could pick it up from a handrail or doorknob and later touch your face. That’s all it takes. Ordinary soap will do just fine. There is no need to buy sanitiser gel. The alcohol in it will only dry out your hands (weakening the skin’s barrier function) while achieving little more than soap.
Stay warm and if you have a cold avoid changes in the temperature of your surroundings for at least two days.
Rest. If you have caught a cold or flu, rest. Stay at home, don’t go to work. You will only struggle with it for longer and your colleagues will not thank you for spreading the virus.
Exercise helps strengthen your immune system and so does the regular use of a sauna at least over the winter. Just a single session is enough to temporarily increase your white blood cell output, thus strengthening the immune system. Avoid both sauna and exercise, however, if you already have a cold and resume when you’re back to normal.
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