This article highlights the intricate relationship between nutrition and immunity, It also emphasises the importance of a balanced diet rich in vitamins, minerals, and probiotics to support immune health.

---

However, the design of our immune system is complicated and impacted by an optimal balance of numerous elements, not simply nutrition, and especially not by any single food or nutrient. A balanced diet rich in vitamins and minerals, combined with healthy lifestyle factors such as appropriate sleep and exercise, as well as low stress, best prepares the body to fight illness and disease.

---

What is our immune system?

On a daily basis, we are continually exposed to potentially hazardous bacteria of various types. Our immune system, a complex network of stages and routes in the body, defends us from both hazardous germs and certain diseases.

It detects external invaders such as bacteria, viruses, and parasites and responds immediately.

Humans possess two types of immunity:

• Innate
• Adaptive

1. Innate immunity

It is a first-line defence against viruses that attempt to infiltrate our bodies, accomplished by protective barriers. These barriers include:

• Skin that keeps out the majority of pathogens
• Mucus that traps pathogens
• Stomach acid that destroys pathogens
• Enzymes in our sweat and tears help create anti-bacterial compounds
• Immune system cells attack all foreign cells entering the body

2. Adaptive or acquired immunity

1. It is a system that learns to recognise a pathogen. It is controlled by cells and organs in the body, including the spleen, thymus, bone marrow, and lymph nodes.
2. When a foreign substance enters the body, these cells and organs produce antibodies, which cause the proliferation of immune cells (including many types of white blood cells) that are specific to the dangerous substance and attack and destroy it.
3. Our immune system then adapts by remembering the foreign substance so that if it enters again, these antibodies and cells are even more efficient and quick to destroy it. Other conditions that trigger an immune response :

Antigens

1. Antigens are materials that the body recognises as alien and harmful, causing immune cell activity.
2. Allergens are a form of antigen that includes grass pollen, dust, food components, and pet hair.
3. Antigens can cause a hyper-reactive response in which too many white cells are released. People’s sensitivity to antigens varies widely.For example, a mould allergy causes wheezing and coughing in a sensitive individual but not in others.

Inflammation

1. Inflammation is a normal and necessary step in the body's innate immunological response. When infections attack healthy cells and tissue, mast cells respond by releasing substances called histamines, which induce inflammation. Inflammation can cause discomfort, swelling, and the discharge of fluids to help wash out infections.
2. Histamines also trigger the release of more white blood cells to combat infections. However, persistent inflammation can cause tissue damage and overwhelm the immune system.
3. Autoimmune diseases such as lupus, rheumatoid arthritis, and type 1 diabetes are partially genetic and cause hypersensitivity, in which immune cells attack and kill healthy cells.
4. Immunodeficiency disorders can depress or completely disable the immune system and may be genetic or acquired. Acquired types are more prevalent, including AIDS and malignancies such as leukaemia and multiple myeloma. In certain circumstances, the body's defences are sufficiently compromised that a person becomes extremely vulnerable to infection by invading microorganisms or antigens.

---

What factors can depress our immune system?

1. Older age: As we age, our internal organs may become less efficient; immune-related organs like the thymus or bone marrow produce fewer immune cells needed to fight off infections. Micronutrient deficits are sometimes linked to ageing, which can exacerbate a deteriorating immune system.
2. Environmental toxins (smoke and other particles contributing to air pollution, excessive alcohol): These chemicals can disrupt or decrease the proper function of immune cells.
3. Excess weight: Obesity is linked to low-grade chronic inflammation. Fat tissue produces adipocytokines, which can contribute to inflammatory processes.  Although research is still in its early stages, obesity has been discovered as an independent risk factor for the influenza virus, probably due to reduced T-cell function, a kind of white blood cell.
4. Poor diet: Malnutrition, or a diet deficient in one or more nutrients, can reduce immune cell and antibody synthesis and activity.
5. Chronic diseases: Autoimmune and immunodeficiency illnesses damage immune cells, potentially disabling them.
6. Chronic mental stress: Stress causes the release of hormones such as cortisol, which inhibit inflammation (which is required to activate immune cells) and white blood cell activity.
7. Lack of sleep and rest: Sleep is a time when the body restores itself by releasing a type of cytokine that fights illness; insufficient sleep reduces the amount of these cytokines and other immune cells

---

Does an immune-boosting diet exist?

Nutrients

1. All cells, including immune cells, require adequate nutrients as part of a diversified diet to function properly. Certain dietary patterns may help the body prepare for microbial invasions and excess inflammation, but individual items are unlikely to provide special protection.
2. Each stage of the body's immunological response is dependent on the presence of several micronutrients. Vitamin C, vitamin D, zinc, selenium, iron, and protein (including the amino acid glutamine) are some of the nutrients that have been identified as essential for immune cell growth and function.
3. They are found in a wide range of plant and animal diets. Diets with limited variety and low nutrient content, such as those based mostly on ultra-processed meals and deficient in minimally processed foods, can have a negative impact on a healthy immune system.
4. It is also thought that a Western diet strong in refined sugar and red meat and low in fruits and vegetables can disrupt good intestinal flora, resulting in chronic inflammation of the gut and weakened immunity.

Microbiome

The microbiome is an internal metropolis of billions of bacteria or microbes that inhabit our bodies, primarily in the intestines. It is an area of significant and ongoing research, as scientists discover that the microbiome plays an important role in immunological function. The gut plays an important role in immunological activity and antimicrobial protein synthesis.

The type of microorganisms that dwell in our intestines is heavily influenced by our food. A high-fiber plant-based diet rich in fruits, vegetables, whole grains, and legumes appears to promote the proliferation and survival of beneficial bacteria.

Certain beneficial microorganisms degrade fibres into short-chain fatty acids, which have been proven to increase immune cell function. These fibres are sometimes referred to as prebiotics since they feed bacteria. As a result, a diet high in probiotic and prebiotic foods may be advantageous.

Probiotic foods contain live helpful bacteria, and prebiotic foods contain fibre and oligosaccharides that feed and maintain healthy colonies of those bacteria.

Probiotic foods include kefir, yoghurt containing live active organisms, fermented vegetables, sauerkraut, tempeh, kombucha tea, kimchi, and miso. Prebiotic foods include garlic, onions, leeks, asparagus, Jerusalem artichokes, dandelion greens, bananas, and seaweed. A more general rule is to consume a mix of fruits, vegetables, legumes, and whole grains to obtain dietary prebiotics.

Chicken soup as medicine? A warm bowl of chicken soup is a popular go-to when we’re feeling under the weather.

Is there scientific evidence that it aids in healing? The short answer is no; there aren’t any clinical trials that show that chicken soup speeds healing any more than other foods. But when breaking down its ingredients, it does appear a worthwhile remedy to try. First of all, chicken soup is light and easy on the stomach when our appetite isn’t great.

Second, it supplies fluids and electrolytes to combat dehydration, which is readily caused by a fever. Finally, a typical chicken soup recipe has a variety of immune-system elements, including protein and zinc from the chicken, vitamin A from carrots, vitamin C from celery and onions, and antioxidants from onions and herbs. This is a nice and relaxing snack to include when you're not feeling well and doesn't require a doctor's prescription.

---

Do vitamin or herbal supplements help?

A single nutritional shortage can change the immune system's reaction. Animal studies have shown that zinc, selenium, iron, copper, folic acid, and vitamins A, B6, C, D, and E deficits can affect immunological responses.

These nutrients help the immune system in several ways

Working as an antioxidant to protect healthy cells, supporting the growth and activity of immune cells, and producing antibodies. According to epidemiological studies, those who are undernourished are more likely to contract bacterial, viral, and other diseases.

Spotlight on vitamin D Vitamin D’s role in regulating the immune system has led scientists to explore two parallel research paths

Is vitamin D insufficiency linked to the development of multiple sclerosis, type 1 diabetes, and other "autoimmune" disorders, in which the body's immune system destroys its organs and tissues? And could vitamin D supplements help boost our body’s defences to fight infectious diseases, such as tuberculosis and seasonal flu?

Eating a high-quality diet, as shown by the Healthy Eating Plate, can help prevent certain nutrient shortages. However, there are particular populations and conditions in which it is not always possible to consume a diverse range of nutritious meals, or in which nutrient requirements are higher. In these circumstances, a vitamin and mineral supplement can assist replace dietary shortages. According to studies, vitamin supplementation can boost immunological responses in certain groups.

Low-income households, pregnant and lactating women, infants and toddlers, and the critically ill are examples of groups at risk. The elderly are a particularly high-risk group. The immune response normally declines with age, as the quantity and quality of immune cells decrease. This increases the likelihood of poor outcomes if the elderly suffer chronic or acute disorders. In addition, about one-third of the elderly in industrialised countries have nutrient deficiencies.

Some reasons include a decreased appetite due to chronic diseases, depression, or loneliness; multiple medications that can interfere with nutrient absorption and appetite; malabsorption due to intestinal issues; and increased nutrient requirements due to hypermetabolic states associated with acute or chronic conditions. Diet variety may also be limited owing to financial restrictions or a lack of interest in cooking for one person; bad dentition; mental impairment; or a lack of transportation and community resources to access nutritious meals.

A general multivitamin/mineral supplement providing the recommended dietary allowances (RDA) may be used in these cases unless otherwise directed by one’s physician. Megadose supplements (many times the RDA) do not appear justified and can occasionally be damaging or even inhibit the immune system (for example, zinc). Remember that vitamin supplements are not a substitute for a healthy diet because no supplement contains all of the advantages of whole foods. Herbals Several herbal supplements have been recommended to improve immune function.

---

What does the research say?

Echinacea: Although cell studies have demonstrated that echinacea can eliminate influenza viruses, little human research has yielded inconsistent results in determining echinacea's active components. Taking echinacea after suffering a cold has not been proven to lessen its length, but taking it when healthy may provide some protection against getting a cold.

Garlic: Allicin sativum, the main element in garlic, is thought to have antiviral and antibacterial benefits on the common cold, although there are high-quality clinical research comparing garlic supplements to placebos. A Cochrane review found only one trial of reasonable quality with 146 participants. Those who took the garlic supplement for three months had fewer colds than those who took a placebo, but once sick, both groups had identical durations of illness.

It is important to note that these findings are based on a single trial and must be reproduced. Tea catechins: Cell studies have indicated that tea catechins, such as those contained in green tea, can inhibit the replication of influenza and some cold viruses while also increasing immunological function.

---

Steps to help support a healthy immune system​​​

1. Consume a healthy diet that includes whole fruits and vegetables, lean proteins, whole grains, and lots of water.
2. A Mediterranean Diet is one option that incorporates these items. If a balanced diet is not readily available, a multivitamin containing the RDA for multiple nutrients may be used instead. Avoid smoking (or stop if you already do).
3. Consume alcohol in moderation. Engage in moderate, regular exercise. Aim for 7 to 9 hours of sleep per night. Try to stick to a sleep pattern, waking up and going to bed at the same time every day.
4. Our biological clock, or circadian rhythm, affects sensations of tiredness and wakefulness, thus following a consistent sleep schedule helps to maintain a balanced circadian rhythm, allowing us to sleep deeper and more restfully.
   Aim to manage stress. This is easier said than done, so try to find some healthy strategies that work best for you and your lifestyle, such as exercise, meditation, a specific interest, or chatting to a trusted friend.
5. Another tip is to practise regular, aware breathing throughout the day and when you feel stressed. It doesn't have to be long—just a few breaths can assist. If you need some help, try this short mindful breathing exercise.
6. Wash your hands throughout the day, including when you come in from outside, before and after preparing and eating food, using the lavatory and coughing or having your nose.
7. Significant studies has shown that specific vitamins, minerals, and vital fatty acids play critical roles in immunity. These nutrients maintain the specialist defences that keep viruses and bacteria out of our systems, eliminate intruders that enter, and aid recovery from disease and infection.

---

Nutrients for the immune system

1. Many nutrients are essential for maintaining a healthy immune system. If you are deficient in any of the nutrients listed above, you are more likely to develop serious disease or infection.
2. Do your normal food selections match the guidelines on this list? Contact a licensed dietitian nutritionist (RDN) to find out how your everyday diet stacks up.
3. If you believe you are coming short, examine the "Where can I get more?" section of the table. We've provided a few food examples to get you started, but the LPI's Micronutrient Information Centre contains nutrition information for many more foods.
4. If you already know that your body is deficient in a particular nutrient, such as iron in the case of anaemia, prioritise that nutrient first.

---

Can supplements help?

While it is ideal to obtain the majority of your nutrients from food, this is not always achievable. The ideal technique is to identify where you fall short and then supplement to cover the gaps. Experts at the Linus Pauling Institute have identified four "immune essential" supplements that all people should explore.

Vitamin C, vitamin D, DHA (an omega-3 fatty acid), and zinc can all aid our bodies against infection. Following our recommendations, you can take one or more of these supplements to support your immune system.

Multivitamins are also vital for achieving your goals. These supplements can help you meet all of the LPI guidelines, particularly for minerals.

Most general multivitamins will meet your needs. An expensive brand may not always imply superior quality.

Important: Make sure you choose the appropriate type, such as those for ladies or older folks.

Multivitamin tips:

1. Your multivitamin should contain 100% of the Daily Value (or close to it) for each of the vitamins and minerals indicated in the table above.
2. Check for quality testing on your supplements, such as the USP or NSF seals.
3. Check if your multivitamin contains zinc. Make sure not to consume more than 40 mg of zinc per day from food and supplements combined.

---

What about older adults?

Our immune systems become less effective as we age. This is due to the fact that older persons do not absorb nutrients as well as younger adults, and we require more nutrients as we age. For these reasons, elderly persons should take specific vitamins.

As a result, the LPI has established particular supplement recommendations for older persons. All of the advice presented here will help persons over the age of 50 support their immune systems.

Caution: Older persons should consume no more than 8 milligrammes of iron and 40 mg of zinc each day.

LPI Recommendations for adults over 50

In addition to the above, look for the following in your multivitamin supplement:

• 2 mg vitamin B6
• At least 100 µg of vitamin B12
• 10-15 mg of zinc
• No iron

Also, make sure you are getting:

• 2,000 IU/day or more from vitamin D from supplements
• 400 mg/day or more of vitamin C from all sources

---

Disclaimer- The views and opinions expressed in this article are those of the author and do not necessarily reflect the official policy or position of M3 India.

About the author of this article:  Pallavi Dubey has done a Master's in Clinical Nutrition & Dietetics, currently working as a Senior Clinical Nutritionist at Recoup Health, Bangalore.