Why a Strong Immune System Matters and How to Strengthen Yours
In the quest for good health and well-being, few aspects of our health are as crucial as the resilience of our immune system. The immune system is a multitude of specialised cells that serve as the body's defence against harmful microbes, including viruses, bacteria, and other invaders. A robust immune system not only protects us from infections but also plays a pivotal role in overall health and longevity. So, what are the best ways to boost our immune system?
Navigating a world with challenges to our immune defences around every corner, from adapting viruses to the demands of modern life, the importance of strong immune support cannot be overstated. Whether you are a health enthusiast eager to optimise your immune function or someone seeking practical strategies for supporting immune health in the face of specific challenges, there are several effective ways to boost the immune system for sustained well-being.
Immune System Boosting Foods
Citrus Fruits
Citrus fruits, including oranges, grapefruits, lemons, and limes, are renowned for their high vitamin C content. Vitamin C is a potent antioxidant that supports the production of white blood cells, crucial defenders of the immune system. Antioxidants help neutralise free radicals, which can cause cellular damage that triggers many health issues. These fruits also contain flavonoids, compounds with anti-inflammatory properties, further enhancing their immune-boosting potential. Incorporating citrus fruits into the diet provides a refreshing and tasty way to ensure the body receives an ample supply of this essential vitamin, boosting the overall resilience of the immune system.
Berries
Berries, such as strawberries, blueberries, blackberries, and raspberries, are essential sources of anthocyanins and quercetin. Anthocyanins and quercetin help combat oxidative stress in the body, reduce inflammation and support immune function. Anthocyanins in berries boost the immune system by supporting the function of cytokines, which control the inflammatory response. Berries can also increase the growth and multiplication of beneficial bacteria in the gut. The beneficial bacteria can then enhance the activity of natural killer and phagocytic immune cells, as well as improve the function of other immune cells, such as T cells.
The wide variety of vitamins and minerals found in colourful fruits contributes to a nutrient profile that supports a healthy immune system. The diverse range of phytochemicals present in these fruits provides a host of immune-boosting benefits, making them not only delicious additions to the diet but also powerful immune-boosting agents.
Leafy Green Vegetables
Leafy greens such as spinach, kale, and Swiss chard are nutritional powerhouses that offer a wealth of vitamins, minerals, and antioxidants. Among these, vitamin A, vitamin C, and various forms of folate play essential roles in supporting immune function. Leafy greens also provide fibre, which is necessary for a healthy gut microbiome. The beneficial bacteria in the gut feed on the insoluble fibre in these fibrous vegetables, which enables them to grow and multiply. The combination of essential nutrients and phytochemicals makes leafy green vegetables a cornerstone in strengthening the immune system to protect the body from microbial invaders.
Onions
Onions are one of the most grown and consumed vegetables worldwide. They contain a total of thirty-four phenolics, including seventeen flavonoids, with quercetin being the most abundant. These compounds possess potent antioxidant and anti-neuroinflammatory properties, with flavonoids in onion peels exhibiting significant positive effects.
Quercetin is also known for its anti-allergic properties, which involve regulating the immune system and inhibiting the release of histamines, compounds that trigger allergic reactions. For this reason, quercetin is often found in treatments for conditions such as bronchial asthma and hay fever. In addition to onions, quercetin is also found in broccoli, apples, berries, grapes, certain herbs, tea, and wine. Whether incorporated into savoury dishes or used as aromatic additions, garlic and onions provide a flavourful means of boosting immune health.
Yoghurt and Probiotics 
Yoghurt, along with other probiotic-rich foods such as kefir and fermented vegetables, serves as a source of beneficial bacteria that promote a healthy gut microbiome. A robust gut microbiome is intricately linked to immune function, as it helps regulate the body's immune responses. Probiotics enhance the production of antibodies and support the activity of immune cells, thereby boosting the immune system's ability to defend the body against pathogenic microbes. Including yoghurt and probiotic-rich foods in the diet not only contributes to digestive health but also plays a crucial role in boosting the immune system. These foods also help reduce the risk of type 2 diabetes, heart disease, and metabolic syndrome.
Nuts
Almonds support the immune system due to their high vitamin E content. Almonds with their skin still intact have been shown to reduce the multiplication and spread of viruses, such as the herpes virus. This is due to the effects of specialised immune cells such as cytokines, interleukins, and tumour necrosis factors.
Pistachios
Pistachios deliver a powerful load of antioxidant and anti-inflammatory compounds, including anthocyanins, flavonoids, and the carotenoids lutein and zeaxanthin. They also contain the immune-boosting vitamins A, B, C, E, and K.
Walnuts
People often celebrate walnuts as a “superfood” because their natural substances work together to reduce the risk of certain types of cancer. Looking like miniature brains, walnuts pack a potent dose of anti-inflammatory omega-3 polyunsaturated fatty acids that support brain health. They also contain beneficial compounds such as tocopherols, antioxidant polyphenols, and ellagitannins.
When you eat walnuts, your gut bacteria convert ellagitannins into ellagic acid, which they then transform into bioactive substances known as urolithins. Some of these, such as urolithin A, possess potent anti-inflammatory properties. Walnuts are high in fibre, making them a prebiotic food for the “friendly” bacteria in the gut, which helps lower the risk of diseases such as colorectal cancer.
Pecans
Like walnuts, pecans also resemble miniature brains, are packed with anti-inflammatory omega-3 polyunsaturated fatty acids, and contain immune-boosting vitamins E, folate, and zinc. These nutrients help the body repair itself, fight off infections, and protect DNA. This is important because damaged DNA has the potential to trigger the growth and multiplication of cancerous cells. Eating pecans can also help lower cholesterol levels, which in turn reduces the risk of heart disease.
Brazil nuts
Along with almonds and walnuts, Brazil nuts are a valuable addition to a healthy immune system. Brazil nuts are one of the best dietary
sources of the anti-oxidant mineral selenium. This is needed for the health of the thyroid gland and to protect healthy DNA. Brazil nuts can boost the body's production of the innate antioxidant glutathione, which has anti-inflammatory effects. Brazil nuts have also been found to be particularly beneficial for individuals with chronic kidney disease. Selenium in them helps mitigate oxidative stress and inflammation.
Seeds
Pumpkin seeds are full of nutrients, including fibre, healthy fats, protein, vitamin E, zinc, magnesium, and folate. However, they also come with a range of polyphenols, phytosterols, flavonoids, and carotenoids. This makes them highly effective in combating oxidative stress in the body. For this reason, research has found them to be beneficial in boosting the immune system. They are also effective in reducing the risk of infections by parasites, as well as diabetes, high cholesterol, and even certain types of cancer, all due to their nutrient-rich profile.
Chia seeds are another seed that can support the immune system. They are full of fibre, both soluble and insoluble. The insoluble fibre keeps the beneficial gut bacteria happy because it serves as food, enabling them to grow and multiply, thereby crowding out pathogenic, infection-causing bacteria. The fibre also has a cleansing effect, grabbing onto chemicals that cause high cholesterol and cancer and removing them from the body. Chia seeds also contain a variety of phytochemicals, including quercetin, kaempferol, caffeic acid, and chlorogenic acid. These help fight inflammation and oxidative stress, which in turn supports the immune system. They specifically support the health of the heart and liver and have anti-cancer benefits.
Vitamins 
Vitamin C
In addition to the benefits already mentioned, vitamin C plays a vital role in maintaining the skin's integrity and strength. The skin is the first line of defence in the body’s immune system, so it is essential that bugs and germs cannot penetrate it. Vitamin C is also vital for healing wounds and cuts, which can serve as an entry point for bacteria, potentially leading to wound infection.
Vitamin E
A powerful antioxidant, vitamin E helps the body combat the effects of oxidative stress. It also plays a crucial role in supporting the immune system by regulating cell signalling and gene expression. Vitamin E also acts as a guardian for vascular health, making it more difficult for blood components to adhere to the walls of blood vessels and helping them function efficiently. It also stimulates the release of prostacyclin, helping to expand blood vessels and prevent blood cells from sticking together.
Immune System Boosting Herbs and Spices
Garlic
Garlic contains allicin, a compound known for its antimicrobial and anti-inflammatory effects. These properties contribute to a strengthened immune response, helping the body ward off infections. For centuries, garlic has been praised for its health benefits. The active ingredient in garlic is allicin but cooking destroys it.
Recent research suggests that garlic may enhance the immune system's performance by activating specific cell types, including macrophages, lymphocytes, natural killer cells, dendritic cells, and eosinophils. It does this through various mechanisms, including influencing the secretion of cytokines, promoting immunoglobulin production, enhancing phagocytosis (the process of engulfing and digesting pathogens), and activating macrophages (cells that engulf and digest cellular debris and pathogens). 
Various diseases develop and progress due to immune dysfunction, and garlic may exert its therapeutic effects by influencing cytokine secretion. This suggests that garlic may play a role in treating and preventing conditions such as obesity, metabolic syndrome, cardiovascular disorders, gastric ulcers, and even certain types of cancer. In essence, garlic seems to have a positive influence on the immune system, potentially contributing to its health-promoting effects.
Ginger
Ginger possesses anti-inflammatory and antioxidant properties, which can help control the ageing process. Its antimicrobial action provides an additional benefit by helping to treat infections. In the body, oxidative stress occurs when the production of free radicals or reactive oxygen species surpasses the antioxidant capacity. An imbalance in the body contributes to heart diseases, neurodegenerative conditions, cancer, and the ageing process. Ginger's bioactive molecules, especially gingerols, have demonstrated antioxidant activity in various scenarios, potentially counteracting the harmful effects of oxidative stress.
Turmeric
A golden spice from the roots of the Curcuma longa plant, turmeric has considerable benefits for the immune system. Turmeric contains approximately fifteen polyphenols, the most active and beneficial of which is curcumin. Curcumin has been found to have anti-inflammatory properties and exhibits strong antioxidant effects.
Research suggests that curcumin may influence the activity of various immune cells, including T cells, B cells, macrophages, and natural killer (NK) cells. These cells play crucial roles in detecting and eliminating harmful bacteria and viruses. Turmeric can further support the immune system because it exhibits antimicrobial properties. It can help combat bacteria and fungi, thereby preventing infections.
Turmeric is also anti-viral, as it inhibits viruses from replicating and spreading. It is particularly effective against the flu and human papillomaviruses, the latter of which can lead to cervical cancer if left untreated. On that note, curcumin has also been found to have anti-cancer properties.
Cinnamon
Cinnamon is a popular spice derived from the bark of trees in the genus Cinnamomum. It is not only known for its warm and sweet flavour but also for potential immune system support. With that said, more research is needed to fully understand the extent of cinnamon's impact on the immune system. Cinnamon contains several beneficial compounds, including cinnamaldehyde, cinnamic acid, proanthocyanidins, tannins, linalool, pinene, and eugenol. These compounds contribute to cinnamon's antibacterial, antioxidant, anti-inflammatory, and antifungal properties. Cinnamon has also been shown to have anti-diabetic properties, as it can help prevent diabetes by regulating blood sugar levels and enhancing insulin sensitivity. Cinnamon can reduce the risk of viral infections by inhibiting the attachment of viral cells to cells in the body.
Basil
Basil, a fragrant herb belonging to the mint family, offers many benefits for immune system support. This fragrant herb contains several beneficial compounds, including D-linalool, eugenol, catechins, quercetin, kaempferol, limonene, anthocyanins, terpinene, tannins, menthol, and rosmarinic acids, as well as potent essential oils.
Linalool and eugenol contribute to basil's anti-bacterial and anti-viral properties, supporting the immune system in warding off infections. Basil also has adaptogenic qualities. Adaptogens are substances that help the body adapt to stress and indirectly support the immune system by helping the body manage stress more effectively.
Basil has been found in numerous studies to be beneficial in the treatment of cardiovascular disease and metabolic disorders, including diabetes and metabolic syndrome. It can also support the immune system by protecting the brain and liver. This is due to its anti-inflammatory, antioxidant, and anti-microbial effects.
Rosemary
Rosemary not only adds an aromatic flavour to dishes but also offers potential benefits for immune system support. Like other herbs, rosemary contains many beneficial compounds that contribute to its antioxidant and anti-inflammatory properties, enabling it to support the immune system. These compounds include linalool, cineole, camphor, rosmarinic acid, limonene, and romano.
Rosemary has strong antioxidant properties. This is because it can stimulate the action of superoxide dismutase, an innate anti-oxidant that is produced in the body. Thyme and sage also produce this benefit. Rosemary also contains carnosic acid, which gives it anti-viral properties. It does this by blocking the viral cells from multiplying. Rosemary is especially effective against viruses that attack the respiratory system.
Lifestyle Practices for a Robust Immune System
Exercise
Regular exercise offers a range of benefits that positively impact the immune system. First, it helps the lymphatic system function more effectively. This is because the lymphatic system relies on regular movement to circulate lymph. It lacks a pump similar to the heart's circulation of blood throughout the body.
Physical activity stimulates the body to produce various immune cells, including white blood cells, which play a crucial role in defending against infections. Intense exercise over a short period can also stimulate the number of natural killer cells present in the body. However, engaging in intense activity over a prolonged period does not further enhance their benefits. Natural killer cells are reduced after a long period of intense exercise. Therefore, less is more when it comes to boosting this aspect of immune health.
That said, if you have an infection, especially one caused by a virus, it is best to avoid physical exercise. Exercising during an infection can increase virus replication and inflammation, particularly with viruses that target the heart and respiratory system. However, research indicates that regular exercise enhances the immune system and reduces the severity and duration of illnesses. In cases of life-threatening viruses like COVID-19, people who exercise regularly are less likely to develop complications or die.
Sleep
Why Lack of Sleep Makes You Grumpy
Most of us are aware that when we don't get enough sleep, we become irritable, snappy, and generally unpleasant to be around. We also tend to get “hangry” — a mix of hungry and angry — which creates a dangerous combination of the two emotions. Sleep deprivation stimulates the production of the hunger hormone ghrelin, which drives us to make poor food choices when we're tired. These include processed foods high in sugar, salt, and fat.
How Poor Sleep Triggers Inflammation and Weakens Immunity
This can lead to weight gain, which in turn can impact the immune system. On top of that, eating a diet high in sugar causes inflammation, reduces immunity in just hours, and increases the risk of developing allergies.
Sleep is closely connected to protecting against neurodegenerative diseases like Alzheimer's. This is because during sleep, the glymphatic system clears away plaques, waste, and proteins that are key features in the development of Alzheimer's disease. Not getting enough sleep can mess with this process. A lack of sleep can also disrupt the blood-brain barrier, which, long-term, can increase the risk of the development and progression of strokes, diabetes, and multiple sclerosis.
Sleep, Learning, and Memory: The Role of BDNF
On another note, sleep also plays a part in regulating learning and memory. It does this by influencing a substance called brain-derived neurotrophic factor (BDNF). When you don't get enough sleep for a long time, BDNF levels can go down. However, a combination of short-term sleep loss and exercise can increase BDNF in the hippocampus, a brain region associated with memory. Therefore, if you had an unsettled night, it is well worth doing some exercise the following day, if only to tire yourself out and improve your chances of sleeping better the next night.
Ensuring you get a good night’s sleep regularly is crucial for maintaining a healthy immune system. Therefore, it is essential to follow good sleep hygiene tips. Sleep in a cool, dark room. Go to bed and wake up at the same time every day. Avoid screens a couple of hours before bedtime to reduce exposure to blue light. Also, get natural daylight as soon as possible after waking up. Click here for more tips on getting a good night's sleep and overcoming insomnia.
Stress reduction boosts the immune system.
When you're stressed, nerve cells in the sympathetic nervous system release substances that influence the immune system. These substances interact with receptors on white blood cells. Immune cells, including natural killer cells, B cells, and T cells, have distinct receptors that influence their stress response.
Another way stress affects the immune system is through three systems in the body. These are the hypothalamic–pituitary–adrenal axis, the sympathetic–adrenal–medullary axis, and the hypothalamic-pituitary-ovarian axis. These systems release several hormones. These include epinephrine, norepinephrine (also known as adrenaline and noradrenaline), cortisol, prolactin, growth hormone, melatonin, β-endorphin, and enkephalin. These hormones bind to specific receptors on white blood cells, affecting their function. When individuals feel stressed, they often drink alcohol and sleep poorly, both of which weaken immunity.
Stress disrupts the functioning of our immune system and is linked to various health issues. Think of it this way: stress can make our immune system behave as if it's constantly dealing with a problem. This reaction is similar to what occurs in chronic inflammatory diseases, such as rheumatoid arthritis. This altered immune function doesn't just affect our physical health; it can also make psychological issues worse. For example, in conditions like irritable bowel syndrome, stress can make stomach troubles worse because of ongoing cortisol activity.
The Hidden Impact of Stress Hormones on Immunity
Stress can increase levels of substances such as proinflammatory cytokines. Researchers have linked these substances to conditions such as schizophrenia. Chronic stress also appears to increase the risk of developing autoimmune diseases. Researchers are investigating how autoimmune diseases influence the body's response to stress. They hope a better understanding will lead to new ways to reduce stress-triggered immune reactions. This will improve outcomes for people with autoimmune diseases.
In diseases such as multiple sclerosis, stress activates certain substances in the brain that cause inflammation, making the disease worse. Having some stress management strategies can help protect the immune system. These include breathing techniques, mindfulness, meditation, and talking therapies.
Reducing Alcohol to Boost the Immune System
When someone drinks alcohol, the body quickly prioritises eliminating it, recognising alcohol as a poison and working hard to remove it.
Alcohol damages the cells that line the digestive system, allowing microbes and toxins to more easily pass into the bloodstream. It also harms T cells and neutrophil immune cells. In the gut, alcohol disrupts beneficial bacteria that support immunity. Alcohol damages gut bacteria and the gut lining, allowing bacteria to enter the bloodstream, trigger inflammation in the liver, and eventually lead to liver disease and cancer. Heavy drinking also increases the risk of lung and respiratory diseases.
Why Even Occasional Drinking Can Impact Recovery and Healing
The effects on immunity can be caused by both long-term drinking and binge drinking. Even small amounts of alcohol can affect the immune system. When people drink alcohol, they tend to become less reserved and take more risks than when they are sober. As a result, they are more likely to suffer accidents such as burns, heavy bleeding, or head injuries. Unfortunately, recovery and healing from these conditions can be hampered due to alcohol disrupting the immune system. Therefore, it is beneficial to keep drinking alcohol to a minimum and avoid binge drinking to protect the immune system.
Diet, exercise, sleep, stress, and alcohol consumption all affect the immune system in various ways. The tips in this article offer guidance on how to protect the immune system effectively. Following them can help individuals live long and healthy lives. However, it is essential to remember that life is for living, and the saying “everything in moderation” applies. You can still protect your immunity without having to give up all the things in life that you enjoy.
Connect with us on Facebook!
Medical Disclaimer:
The content on Jane Stevens Nutrition is for educational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider before making changes to your diet, lifestyle, or supplement routine. Use of this information is at your own risk. Jane Stevens Nutrition is not liable for any outcomes resulting from your use of this site. Full medical disclaimer here
