Having a healthy immune system is important for many reasons. During cold and flu season, a properly functioning immune system can mean the difference between falling victim to multiple illnesses or warding them off.

Most of us admittedly do not pay much attention to our immune system until we realise it isn't working properly. If you are on your fifth head cold of the season it might be time to reevaluate the status of your immune system and take measures to boost it if warranted.

The First Line of Defence

A healthy immune system serves as the first line of defence in protecting us from illness by producing antigens. It consists of a complex network of cells, tissues and organs that join forces to fight off hostile invaders to try to keep them from entering our bodies.

These invaders can be bacteria, parasites and viruses. Even if one of these unwanted guests manages to get by the antigens, a healthy immune system has a second line of defence waiting: white blood cells. Chemicals, proteins and white blood cells team up to attack and destroy these unknown substances. When working optimally, our immune systems are capable of eradicating nearly any threat.

9 Warning Signs of a Weak and Languishing Immune System

Let's talk about some warning signs that signal your immune system is underperforming. The most obvious sign that your immune system is lacking comes in the form of constant sniffles, sneezes and other signs of common colds and viruses.

An average adult can expect to experience two to three colds annually. If your immune system is healthy, your body will be able to recover within 10 days. If you are constantly ill or have difficulty kicking an illness, it might be time to boost your immunity. We will talk about ways to do that later. Some less obvious signs of an improperly functioning immune system:

• Weight gain
• Chronic gut troubles such as bloating, gas, diarrhoea, constipation and food sensitivities
• Wounds are slow to heal.
• A feeling of exhaustion that is not caused by a lack of adequate sleep
• Two or more ear or sinus infections each year
• Problems falling asleep or not being able to sleep through the night
• Chronic inflammation
• Hormonal imbalances
• Anxiety, depression or just an underlying feeling something isn't right

Building a High Functioning Immune System

Building a healthy immune system primarily involves proper nutrition and exercise. Studies have shown that engaging in regular, moderate exercise boosts the body’s immune response.

The other necessary component is proper nutrition, which includes natural foods rich in several vitamins and minerals. According to a study on the role of nutrition in boosting immunity, proper nutrition is an essential building block of a healthy immune system. The vitamins and minerals most beneficial to the immune system are vitamin C, zinc, methylglyoxal, antioxidants, vitamin E, iron and MCT oil.

Ideally, the body should consume whole food sources containing these crucial vitamins and minerals. However, it is not always possible to do so, as some are incredibly rare, expensive and difficult to find. When this happens, supplementation is an acceptable alternative to ensure your body is receiving the amounts required to boost and maintain your immune system.

Beware of Immunity Supplements With Ingredients From Foreign Factories (such as China)

Not all supplements are created equally. Some contain inferior ingredients and are not any more beneficial to the immune system than taking a placebo. Supplements produced in factories outside the Australia are especially problematic due to lower quality standards and looser regulations.

A recent example of this is the problems surrounding ascorbic acid — commonly known as vitamin C — produced in China. It is China’s most exported vitamin product. Ascorbic acid products produced by China may not contain the levels of active ingredient claimed. Changes to how food and supplements are labelled in China were proposed at the end of 2019.

Both measures addressed the issues frequent to Chinese product labelling. For now, it is up to the consumer to evaluate whether a supplement is of the highest quality. Keep in mind that even though a product claims to be all-natural, it does not mean it contains quality ingredients.

7 Critical Science-Backed Super Nutrients For A Bulletproof Immune System (and the leading natural whole-food sources)

Now that you understand how a healthy immune system works and the importance of choosing quality sources of vitamins and minerals to support a strong immune system, let's discuss the seven best ways to boost your immunity.

1. Vitamin C

There is a reason vitamin C has earned the designation of the king of immunity vitamins. It is considered an essential vitamin for the human body. That means your body cannot produce it on its own, so it must be obtained via outside sources such as whole foods and supplements.

The recommended daily allowance for vitamin C is 75 mg for women and 90 mg for men. Vitamin C is a powerful antioxidant proven to strengthen the body’s immune system. Numerous scientific studies have verified the importance of its inclusion in a healthy diet.

Among the proven benefits: - May reduce the risk of chronic disease by protecting cells from free radicals - May help control high blood pressure by relaxing the blood vessels carrying blood from the heart - May help prevent iron deficiency by improving the body’s absorption of iron when taken with vitamin C-rich foods - May protect against Alzheimer’s and dementia by reducing oxidative stress and inflammation near the brain, spine and nerves Almost all citrus fruits contain high levels of vitamin C.

Oranges and Kakadu plums have the highest levels of vitamin C. Most people are familiar with oranges, but many are unaware of the power of the Kakadu plum.

Pale green in colour, these tiny powerhouses are highly nutritious and contain a whopping 3,230 per cent of the daily recommended intake of vitamin C. However, Kakadu Plum supplements are incredibly difficult to find. This could be something to do with the fact that it can only grow in very unique parts of Australia and costs over $500.00 per kilo...

2. Zinc

Zinc is another amazing powerhouse, known for its proven ability to stop viral replication. It is used by our bodies in many ways and is the second-most common trace mineral in the human body. It is virtually present in every cell and is needed by more than 300 enzymes that aid in digestion, nerve function and metabolism.

Zinc boosts immunity, accelerates wound healing and may reduce the risk of age-related diseases like macular degeneration and infection. Many whole foods are rich in zinc, with red meat among the best. Zinc is found in high levels in beef, lamb and pork. Just one 3.5-ounce serving of ground beef contains 44 per cent of the recommended daily value of zinc. Other foods containing naturally high levels of zinc include the Australian Davidson plum.

There are four varieties of this amazing superfood. They are very acidic, so they also contain a high level of vitamin C. Because of its rarity, the Davidson Plum is difficult to find and expensive.

3. Methylglyoxal

Touted as a top-secret weapon against disease, this natural ingredient can only be found in manuka types of honey. Made in Australia and New Zealand by bees pollinating the manuka bush (Leptospermum), it has a proven reputation as a fierce natural anti-inflammatory and antioxidant, providing the body with round-the-clock protection.

It successfully soothes sore throats and alleviates symptoms associated with the common cold. While the honey is available in both Australia and New Zealand, the Australian version is superior due to the exceptionally high levels of its medicinal properties. A study conducted by AgriFutures Australia determined at least seven Australian Leptospermum varietals were as active or more active than one species found in New Zealand, increasing the medicinal worth of the Australian variety.

4. Antioxidants

It is a proven fact that when our bodies are under stress — especially constant stress — our immune systems work less efficiently. Have you ever been stressed over a big meeting at work and then come down with a common cold or other illness as soon as the stress subsides? It is not a coincidence.

When the human body is under stress, the immune system’s ability to fight off antigens is significantly reduced, making us more prone to illness. So while the stress of that big meeting at work did not cause you to get physically ill, it contributed to weakening your immune system — such that when your officemate with the sniffles sat next to you at the meeting, you were more likely to catch his cold.

Stress inhibits the body’s ability to produce white blood cells, which are responsible for killing viruses and bacteria that invade our bodies. Stress, in turn, triggers inflammation, which can lead to an overworked and suppressed immune system. Some amazing whole foods are excellent sources of natural antioxidants.

Ashwagandha and Kakadu plums are two of the most potent adaptogens for reducing stress and boosting immunity. Adaptogens act like mini vaccines in our body, inoculating us from the ill effects of stress. When we can adapt to stressful situations, we are more likely to stay healthy. An evergreen shrub that grows in India, the Middle East and parts of Africa, Ashwagandha is one of the most potent adaptogens.

Its roots and reddish-orange fruit have been used for centuries for their medicinal properties. Research has shown it is a beneficial treatment for inflammation and tumour growth. Ashwagandha is a known reducer of cortisol levels, making it ideal for boosting immunity during times of stress. Chronically elevated cortisol levels can lead to high blood sugar and increased fat storage in the abdomen region.

Kakadu plum, in addition to being high in vitamin C, is an amazing source of antioxidants. With antioxidant levels 5.6 times higher than that of blueberries, Kakadu plums force the body to release more cortisol, which prevents the suppression of the immune system. The high level of antioxidants in Kakadu plums makes it an excellent ally in the fight against free radicals, which are linked to health issues like cancer, diabetes, autoimmune conditions and brain degeneration.

5. Vitamin E

Vitamin E is valuable to the immune system since it helps protect the integrity of immune cells. Found in many whole foods, vitamin E is fat-soluble, which means our bodies store it until it is needed. Vitamin E may help repair damaged cells and can be useful for individuals exposed to environmental or lifestyle risk factors like cigarette smoking, air pollution and high levels of ultraviolet light.

Some natural sources of vitamin E include dry roasted sunflower seeds, hazelnuts, peanuts, and almonds; spinach; broccoli; kiwifruit; mangoes; and raw tomatoes. Another food rich in vitamin E is the Australian Finger Lime. The rare fruit of a rainforest tree, the Australian Finger Lime was nearly extinct thanks to overzealous European explorers clearing the bush for farming.

Thankfully, a few of the trees survived in isolated areas of the sub-tropical rainforest so that we could enjoy this magnificent fruit today. While no longer on the verge of extinction, the Australian Finger Lime is still extremely rare and therefore on the expensive side.

6. Iron

Iron deficiency, especially in women, is the world’s most common mineral deficiency. Scientific studies have shown that iron-deficient anaemia can have a detrimental effect on the functioning of our immune system. Sufficient iron levels in the human body are necessary for destroying the shells that protect harmful bacteria and viruses against our disease-fighting cells. Many foods are naturally rich in iron.

Among them: lean red meat, liver, chicken, seafood, lentils and beans, tofu, dried fruits, and fortified breakfast cereals. Two of our favourite superfoods, Australian Finger Lime and Kakadu plum, are two of the most potent plant-based sources of iron. One serving of Kakadu plums contains 13.3 per cent of the daily recommended intake of iron, while Australian Finger Limes have 2 per cent of the recommended daily value.

7. Liposomal Delivery System

Digestive issues, as mentioned, are a huge red flag that your immune system may not be functioning properly. There is an added complication to digestive difficulties: Vitamins and minerals needed to boost the immune system cannot be properly absorbed into our bodies with an improperly functioning digestive system. It is a vicious cycle.

Even when functioning properly, the digestive system is only capable of absorbing a tiny fraction of the vitamins and minerals we ingest. The rest is flushed out of the body without ever being used. This is where the production of red and white blood cells comes into play. Both are crucial for maintaining a well-functioning immune system.

One of the best ways to combat a poor digestive system and improve the body’s liposomal delivery system is with Medium-Chain Triglyceride (MCT) oil. It is easily absorbed and rapidly digested, making it an excellent choice for strengthening the immune system. MCT oil is based on natural compounds called liposomes, which serve as the body’s delivery “vehicles,” transporting vitamins and minerals from the oil directly into the body’s cells.

These natural micronutrients can break through the walls of the intestines and enter the bloodstream directly. A clinical study of 24 volunteers revealed that 1 gram of Liposomal vitamin C produced an absorption rate six times higher than taking vitamin C in traditional tablet form. Another clinical trial conducted by Princeton Consumer Research revealed that a liposome-encapsulated vitamin C significantly improved skin elasticity and reduced the appearance of fine lines and wrinkles as compared with regular supplements.

MCT oil may also help control blood sugar levels and support diabetic management, especially for individuals with type 2 diabetes. Additionally, studies have indicated it is beneficial in reducing risk factors associated with heart disease, including high cholesterol. MCT oil is most commonly sourced from coconut oil. More than 50 per cent of the fat found in coconut oil comes from MCTs.