Boost Your Immunity With Better Food Choices

Everyone wants to be healthier, right?

And especially we want to avoid the usual colds and sniffles, or the flu whenever possible and that means boosting your immune system – but did you know that you can make specific food choices to improve your immunity? But that means more than just eating a bit of this or that, you need to look at everything you are eating and how it all goes together in your body – but if you do it right, you can eat better and stay healthier.

Eat better and stay healthier

Dietician Nicola Walters says that in order to enhance your immune status – and protect against the damage done by stress, poor diet and environmental toxins – you need to optimize your overall nutrient intake and focus on maintaining better-quality daily nutrition.

Photo by Markus Spiske on Unsplash

“You cannot follow an unhealthy eating plan and then supplement to boost your immunity. This will never work. You need to be consistent in optimising your overall nutrition status. Only then will increasing the specific amounts of ‘immune boosting’ nutrients, when the cold and flu season approaches, work to increase your level of protection against illness,” explains Walters.

“You require a colourful diet consisting of whole grains, monounsaturated and omega-3 fatty acids, and lean proteins (which are inclusive of plant-based proteins). You should maximise your intake of antioxidants and phytonutrients by following the guidelines of eating the rainbow,” she says. This is particularly important in the winter months and for individuals who are more at risk.

The immune system is a network of cells, tissues and organs that work together to protect the body. The leukocytes, or white blood cells, come in two basic types and assist in finding and breaking down disease-causing substances and organisms. The two basic types of leukocytes are phagocytes and lymphocytes. Phagocytes fight foreign organisms/substances, while lymphocytes provide the body with a memory of previous foreign organisms/substances in order to assist with their effective future recognition and elimination.

Walters explains:

“Due to poor diet and stress, as well as environmental toxins, free radicals build up and can cause damage to the cells of the body, which can increase risk of infection and impact negatively on optimum immune function. As a result of this, antioxidants – which can help to reduce damage caused by free radicals – can be focused on when eating to boost your immune system, and provide extra support during vulnerable periods.”

Eat To Protect Your Immune System From Stress

Walters believes that the immune system becomes significantly vulnerable during periods of high stress. During this time, your nutrient requirement will increase because vitamins and minerals are being used at higher rates.

“This is where B vitamins are indicated for a healthy central nervous system. If you know that you are suffering from stress, make sure to increase the complex of B vitamins in your diet. Quality food sources for vitamin B include almost all whole grains, vegetables and fruits. You can also focus on vitamin C-rich foods and Zinc-rich foods (spinach, asparagus and mushrooms),” recommends Walters.

Fast Fact: Walters says there is no added immune-boosting benefit to supplementing vitamin C over and above the required amount. The recommended dietary allowances (RDA) for males and females older than 19 are 90 mg and 75 mg daily, respectively.

The Importance of A Healthy Gut Microbe

Walters explains that a healthy microbiome in the human gut has a direct role in optimal immune system function. It contains the largest number of immune cells in the body, constituting approximately 60% of the entire immune system. The colonies of gut flora that reside in the human gut can increase antibodies and play a role in fighting infection as well.

Walters adds that due to this, it is important to encourage a balance of the correct bacteria in your gut. The gut microbiota may be compromised by stress, poor diet or past use of antibiotics.

Evidence-based reviews indicate that certain strains of probiotics contribute to the microbial balance of the gastrointestinal tract, supporting the immune system and reducing inflammation in the gut.

Prebiotics are non-digestible food ingredients that stimulate the growth or activity of bacteria. They provide the nutrients for the multiplication of a desired probiotic and for other species of micro-organisms in the gut that may be favourable to health and immune function.

She adds that quality food sources of prebiotics include fibre-rich foods, Jerusalem artichokes and naturally fermented foods such as yogurt, kefir and kombucha.

Fast Fact: A healthy gut is also maintained through adequate exercise (guidelines encourage >150 minutes of physical activity per week for optimal health) and sufficient daily water intake.

Vitamin D, Iron & Omega-3

Walters says that if you do not have an iron deficiency, it is best to get your iron from a balanced eating plan and not from supplementation. While iron is useful in the proliferation and maturing of immunity cells, evidence has linked excess iron levels, which can be caused by unnecessary supplementation, to the compromised ability of phagocytes in killing micro-organisms. This negatively affects immune function.

She stresses the importance of omega-3 fatty acid supplementation in the event that your intake of fatty fish, such as salmon, pilchards, mackerel and sardines, is low. Omega-3 fatty acids need to be taken in order to balance out omega-6 fatty acids.

Both omega-3 and omega-6 fatty acids are considered essential fatty acids; however, omega-6 fatty acids are found in high concentrations in the modern diet due to processed foods and edible oils, whereas omega-3 fatty acids are not eaten in the same proportions. Reaction in the body with omega-3 fatty acids form end-stage metabolites that help to reduce inflammation; therefore, the presence of omega-3 in the diet is important.

“Chronic, low-grade inflammation compromises the immune system and is evident in all chronic and lifestyle disease,” notes Walters.

With regard to vitamin D and immunity, a number of vitamin D receptors have been found to be expressed in immune cells. Walters says that recent research shows that vitamin D can modulate the innate and adaptive immune response.

So remember, boosting immunity is more than just a bit more of this or a touch less of that – it’s about looking at everything you eat and making everything you eat, better for your immune system.