How your nervous system can suppress your immunity

Our bodies are amazing functioning machines. Did you know that when the body is faced with a challenge, it responds to this by turning on adaptive pathways until the challenge or threat has passed?

These major stressors can trigger our ‘flight or fight’ response; some of this stress comes from day to day stress in our lives (physiological and emotional) and can lead to an increased risk of infection by respiratory viruses.

Most of you would have experienced periods of high stress from work, or home and in return had the flu, chest infections or mouth full of ulcers.

Scientists have found that injury to the brain and spinal chord result in considerable weakening of the immune system.  They have found this is a result of a disruption to the nervous system, which usually works to protect the body by triggering the immune system.

Researchers have found a correlation between the nervous system, the adrenal glands and our hormone control centers.  When damage occurs from stress this causes an alteration in hormone levels, leading to a dramatic decrease in the number of immune cells.

Did you know that our adrenal glands produce a hormone called cortisol, which is needed for balancing our blood sugars? But when stressed or in flight or fright, we produce more cortisol and adrenaline, disrupting the normal function of your adrenal glands. 

The alteration of hormone levels leads to a decrease in the number of immune cells.  This allows scientists and nutritionists to further understand the correlation and the link between the nervous system and the immune system.

Healthy eating to support the immune system

Its important to treat your body like a high performance car, by providing it with the correct fuel.

Foods that are high in sugar and saturated fats (fried and fatty foods) can cause over activity of the immune system, while omega-6 and animal fats can lead to inflammation, fatigue and damaged blood vessels.

Anti-inflammatory properties can be gained from a diet rich in foods that are high in:

Vitamin C, such as fresh beetroot, broccoli, cantaloupe, cauliflower, kiwi, orange, papaya, red, green or yellow capsicum, sweet potato, strawberries and tomatoes.

Omega-3 found in oily fish such as salmon, mackerel, tuna and sardines.

Wholegrain’s are recommended while avoiding refined grains, such as white breads, cereal, rice and pastas, which can cause inflammatory responses to worsen.

Fibre such as whole grains, bananas, oranges, green leafy vegetables, beans and legumes, artichokes, bitter gourd, cabbage, spinach, lettuce, kale, zucchini squash, celery and parsley, these are not only a good source of fibre but also vitamins A, C, iron and potassium.

Vitamin E, such as dark leafy greens which protects the body from inflammation-causing cytokines. Highest concentrations of vitamin E can be found in spinach, kale and broccoli; these vegetables also contain good levels of calcium and iron.

Almonds and walnuts are another good source of vitamin E, fibre, calcium and alpha linoleic acid (ALA).

Yellow and red capsicum, and chili, are all high in anti-oxidants and have anti- inflammatory properties.

Turmeric and ginger have been shown in studies by Surh et al, 2002 to have an anti-inflammatory effect. They found that turmeric helps to turn off NF-kappa B, which is a protein in the body that regulates the immune system and triggers the inflammation process.

All berries are high in anti-oxidants and have anti-inflammatory properties, while tart cherries are said to have the highest anti-inflammatory content of any food.

How else can I help my immune system?

Sleep

Sleep is one of the most important activities for your body alongside breathing, hydration and food.  Inadequate sleep leads to an increase in cortisol and sugar cravings, and lowering of the immune system.

A study by Trenell, M et al, 2007, found the less sleep you have the more insulin resistant you get and this promotes hunger as a stress response.

Action steps you can follow:

• Try a chamomile tea before bed, and make sure you have good sleep hygiene. 
• This includes the removal of all external lights, make sure the room is darkened and set at a temperature your body feels comfortable. 
• Avoid screen time 30 minutes before bed.

Exercise

For your immune system and nervous system to function at its optimum it needs balance and harmony.  Along side a healthy diet, it is recommended that we exercise at least 30 minutes a day.

Exercise improves cardiovascular health, blood pressure, helps control bodyweight, and protect against a variety of diseases.  The movement of blood around the body allows the cells and substances of the immune system to move through the body freely and efficiently.

Action steps you can follow:

• Incorporate at least 30 minutes exercise into your daily routine, as exercise improves insulin sensitivity in skeletal muscle and fat tissue.  Exercise also reduces body weight, lowers blood pressure, lowering triglyceride levels and increasing high density lipoproteins (HDL) levels
• Incorporate yoga, mindfulness, meditation and a brisk walk in the outdoors into your exercise routine to reduce stress, and reduce cortisol in the body and improve immune cell activity.

For extra support with your immune system please make an appointment with one of our nutritionists today.

References:

1. Carol Byrd-Bredbenner, Gaile Moe, Donna Beshgetoot, Jacqueline Berning 2009, Wardlaws’s Perspectives in Nutrition, 8th edn, USA.
2. Joseph E.  Pizzorono Jr, Michael T.  Murray and Herb Joiner-Bey, (2002).  ‘The Clinician’s Handbook of  Natural Medicine’,  2nd edition,  Churchill Livingstone, US.
3. Kawli, T., He, F., and Tan, M-H (2010).  ‘It takes nerves to fight infections: Insights to neuro-immune interactions from C. elegans.’ Disease Models and Mechanisms 3:721-731.
4. Science Daily, An interconnection between the nervous and immune system, 19th of September 2017. Sited 20th of March 2020.  https://www.sciencedaily.com/releases/2017/09/170919102530.htm
5. Surh., Young-Joon. (2002)  “Anti-tumor promoting potential of selected spice ingredients with antioxidative anti-inflammatory activities: a short review” Food and Chemical Toxicology 40, 8, 1091-1097.
6. Trenell, M., Marshall, N., Rogers, N (2007).  ‘Sleep and Metabolic Control: Waking to a Problem?’ Clinical and Experimental Pharmacology and Physiology. 34, 1-2, 1-9.