The human immune system can be divided into 2 key parts: the innate (non-specific) and adaptive (acquired) immune systems.
The innate immune system is our first line of defense and is designed to keep pathogens and foreign particles out of our body. It includes barriers such as our skin, gastrointestinal tract, eyelashes, nasal hair, mucous, bile, tears, sweat, gastric acid and digestive enzymes. At times, there may be an inflammatory response which includes pain, swelling, redness and even fever to fight off the invading pathogen.
If pathogens and foreign particles manage to infiltrate the physical, chemical & mechanical barriers of our innate immune system, then the cells of our adaptive immune system (B cells & T cells) kick into gear and target the specific pathogens more accurately. The adaptive immune system produces memory cells and this explains why there are some illnesses that you’ll only get once in your life and why we can recover from the common cold quicker if we’ve had it before.
The above is a very basic introduction into the complex workings of our immune system. However, it hopefully gives you some idea of what’s involved and that our immune system is constantly ‘on guard’ trying to protect us.
Let’s investigate 7 key dietary and lifestyle factors that can support our immune system:
1. STRESS REDUCTION
High levels of physical, mental and emotional stress can suppress our immune function. Some suggestions for managing stress include: yoga, meditation, exercise, immersing yourself in nature (bush walks, gardening, a visit to the ocean) and practicing gratitude.
2. QUALITY SLEEP
This one is very important. Sleep deprivation suppresses our immune system. Aim for 7-9 hours per night.
3. A HEALTHY GUT
Approximately 70% of our immune system is in our gut! So if you’re experiencing gut issues, this could be comprising the healthy functioning of your immune system. The time to address this is now!
4. MODERATE & REGULAR EXERCISE
A lack there of or excessive exercise can affect the immune system. Aim for moderate levels of exercise, even a 30-45 minute brisk walk at least few times per week.
5. REDUCING ALCOHOL CONSUMPTION
Alcohol can damage the gut and also contributes to dehydration. It’s important to stay hydrated when you’re sick to keep our mucous membranes healthy. Excessive caffeine consumption can also contribute to dehydration.
6. QUIT SMOKING
Not only is it damaging to our respiratory and cardiovascular systems, it can also damage the mucosal lining in our gut and result in impaired mucosal immune response.
7. A HEALTHY & BALANCED DIET
This point is crucial and as a clinical nutritionist I am always encouraging the consumption of plenty of fresh and in season vegetables and fruit! Fresh produce! Lots of plant-based foods. I am also encouraging my clients to get in the kitchen and cook. When you prepare your own meals, you know exactly what's going into your meals. You're in control of your health.
Approximately 4% of Australians eat the recommended serves of vegetables and fruits per day. Think about that for a moment. That means that close to 96% of us don’t eat enough vegetables/plant matter per day and are therefore missing out on essential nutrients.
Malnutrition affects the innate and adaptive immune system as well as our microbiome. In our modern western world, many of us are overfed however undernourished.
KEY NUTRIENTS FOR A HEALTHY IMMUNE SYSTEM
Other Foods to consume to support immunity include:
Garlic, ginger, medicinal mushrooms (Shitake & Resihi)
Add these to soups, risotto's, stews, curries and stir-fries
Plenty of fresh water – approximately 2L per day (filtered if possible)
Nourishing and hydrating soups and broths (especially bone broth & chicken soups)
Culinary herbs and spices such as oregano, rosemary, thyme, parsley and turmeric
Foods to reduce:
Sugars (including fruit juice, cordials, soft drinks), refined flour (white bread & white pasta) - these foods promote inflammation, are nutritionally lacking and can increase blood sugar levels which can all decrease the effectiveness of the immune response.
Ultra processed foods - I talk about these ‘food like substances’ regularly and encourage my clients to ditch them in favor of wholefoods.
Alcohol and Caffeine
Are Dietary Supplements Necessary?
They can be, especially if you have any nutritional deficiencies, are not eating a balanced diet or are following a restrictive diet (vegan, ketogenic, FODMAP).
As previously mentioned, only 4% of Australians are eating the recommended 5 serves of vegetables per day. Therefore, most of us could probably benefit from a supplement boost from time to time.
Please, as always, never self-prescribe. Leave that to the professionals. Dosages vary depending on your individual circumstances. Also, the quality of the products available in the supplement industry can vary greatly.
If you suffer from chronic or recurring infections, your immune system may be exhausted and in need of some additional support. Your gut health may also require some attention and nourishment also.
For personalised nutritional advice to support your immune system, please get in touch today to arrange a consultation:
https://hanna-watson-clinical-nutrition.cliniko.com/bookings#service
References:
Kau, A, Ahern, P, Griffin, N, 2011, 'Human nutrition, the gut microbiome and the immune system', Nature vol. 474 pp. 327- 336
Vieira, A, Teixeira, M, Martins, F, 2013, 'The role of probiotics and prebiotics in inducing gut immunity', Frontiers in Immunology, vol.4 pp.1 -12
The Innate and Adaptive Immune Systems - InformedHealth.org
viewed 15/03/2020, https://www.ncbi.nlm.nih.gov/books/NBK279396/
