Our immune system is our first line of defence from incoming pathogens, however often times our food, other health and lifestyle choices can put extra strain on this essential body system. Factors that can negatively affect immune function is poor dietary intake leading to imbalanced gastrointestinal health and nutrient deficiencies, inadequate energy intake and hydration, inadequate sleep, alcohol and smoking, stress levels and not exercising. Common signs of impaired immune health are recurrent sicknesses or infections, gastrointestinal issues, high stress levels, slow wound or injury healing, consistently feeling tired.
To make sure we are putting our best foot forward especially coming into the cooler season let’s break down the key factors to not only avoid being sick but also optimise recovery times. Firstly, cooler weather affects the body when cold air enters the upper respiratory system making your immune system less able to fight viruses such as cold, flu and COVID-19. Further, once we are sick and even are feeling like we are on the mend, the immune system can still be compromised depending on immune system health and the type of virus contracted. For example, the common cold takes 3-4 days for the immune system to develop antibodies to fight the illness however for COVID-19 research is showing immune system can be compromised for weeks if not months.
How we can optimise immune health through nutrition is firstly by ensuring we are hydrated and meeting daily energy and nutrient needs. This practically looks different for each person based on age, gender, weight, daily activity levels and any health factors that impact on absorption of nutrients and baseline immune function.
To meet hydration, energy and nutrient needs we want to ideally eat until we feel satisfied and work in line with appetite cues, meaning eating every 2-4 hours within waking hours is ideal to manage appetite in line with daily activities. Next, consider the variety of food we are eating on a daily basis as each different food contains different types and combinations of nutrients. These types of foods include colourful vegetables and fruit, wholegrains, nuts and seeds and leaner varieties of meat, seafood and dairy, ideally opting for grass-fed meats where possible. As for hydration we want to sip this throughout the day giving the body the fluid replenishment inline with fluid expenditures of urine, sweat and other bodily fluids. Minimum needs according to best research for hydration is 30-35ml per kilogram of body weight, with people in overweight and obese categories potentially needing to adjust this measure to ensure optimal hydration levels. Further, if sweating or excessive fluid losses occur it is recommended to replace 125-150% of and fluid lost.
In contrast, limiting food and total energy intake places further stress on the body and subsequently the immune system. Similarly eating processed food high in salt, sugar and fats that are low in micronutrients and fibre also increase inflammation and weaken gastrointestinal health defences. Being dehydrated also influences immune function by reducing the body’s ability to clear waste products including toxins.
In addition to baseline nutrients, another key parameter to support immune health is adequate quality sleep. For adults, many research studies support the need of 6-9 hours each night with this quantity varying depending on muscle recovery needs. As an example, for people undertaking weight training or strenuous activity creating muscle damage, sleep quantities closer to 9 hours is more beneficial. When sleep quality is impaired or total quantity is low, protective immune system functions are produced in lower quantities that result in people becoming more susceptible to becoming sick and more likely to require longer recovery times from illnesses.
Stress levels especially those that are chronically or repeatedly elevated, also negatively impact immune function. Importantly stressors can be elevated from circumstantial, for example financial or relational, as well as physical such as exercise. Despite exercise providing numerous health benefits it also increases stress on the body initially which can jeopardise immune function effectiveness especially when it is already fending off an illness.
Therefore, managing stress is important where possible while also employing stress management strategies when levels are elevated as well as managing exercise load when feeling symptomatic.
Supplements to support immune function are also beneficial when there is increased requirements and dietary intake is insufficient. The ideal is to gain these nutrients from food first as nutrients are better absorbed and utilised by the body. Key nutrients for immune function are zinc, vitamin C and vitamin D while increased requirements are present during illness.
Other supplements may also be conditionally beneficial to correct individual micronutrient deficiencies in vitamin A, vitamin E and selenium as these nutrients are needed in key areas within the immune system. Having yearly blood tests measuring these levels can provide further information as to whether supplementation may be warranted.
Zinc:
Zinc is naturally found in a range of foods namely oysters, red meat, poultry, eggs, pumpkin seeds, nuts and wholegrains. When supplementing, we ideally want to opt for zinc diglycinate for optimal bioavailability, in a dosage of 70-100mg has been shown to reduce symptoms and reduce ongoing colds especially when consumed in multiple smaller doses throughout the day. It is not recommended to continue with these elevated dosages as women require 8mg/day while men require 14mg/day with the upper limit being 40mg. It is also important to note that women who are pregnant and breastfeeding have increased needs; 10-11mg and 11-12 mg/ day respectively.
Vitamin C:
Despite Vitamin C not directly being used within the immune system, vitamin C plays a pivotal role in reducing extra stressors in the body which can compromise the immune system’s ability to fight illnesses. Due to this, when sick the body’s absorption rate of vitamin C naturally increases meaning more vitamin C is absorbed from foods we eat.
Food sources rich in vitamin C include berries, citrus fruits, kiwi fruits, capsicum, tomatoes, cruciferous vegetables and white potatoes. It is important to note however that vitamin C is very temperature sensitive meaning that vitamin C content is diminished when these foods are cooked.
Supplementation of 1000-2000mg/day has been shown to be beneficial, however this is when this absorption is broken up into multiple doses similar to what you would expect from food sources.
Vitamin D:
We gain vitamin D largely from skin exposure to sunlight. This can be challenging in colder months, for people working indoors, those using sunscreen on exposed skin and those with potentially poor absorption such as people with darker pigmented skin. Vitamin D has been largely shown to be beneficial only when deficient, primarily focusing on COVID-19 illnesses. For adequate sunlight exposure, ideally 60-75% of body skin is required to be exposed for 10 minutes each day. Some research supports early morning light being more beneficial which also generally coincides with lower UV exposure resulting in less skin damage.
When supplementing, ideally we want to have a blood test prior as vitamin D is a fat soluble nutrient meaning prolonged high dose supplementation can lead to toxicity. For illness much research supports 400IU to 800IU each day while symptomatic.
For further information on how to optimise your personal immune function please contact Motion Health Rehabilitation and Performance, we would love to support your health journey.
1800 417 799
www.motionhealthrehab.com.au
Locations: Capalaba & Underwood & Bulimba & Brookwater
