Research points to foods that boost your body’s defenses

In a recent review in the magazine Food sciences and nutritiona team of researchers has summarized current medical knowledge about the role that certain common foods play in strengthening the immune system. The extensive article discussed the benefits of consuming fruits, vegetables, herbs, animal products and other foods for maintaining a healthy immune system.

Study: Common Foods for Boosting Human Immunity: An Overview. Image credits: Danijela Maksimovic / Shutterstock

Background

The human immune system protects the body against pathogenic invasions. People are born with innate immunity (with cells such as macrophages and neutrophils). Some immunity (such as some types of white blood cells or lymphocyte cells) is acquired through exposure to pathogens. However, scientists have long known that a healthy diet is crucial for maintaining and improving immunity. A dysfunctional immune system can lead to problems such as bronchial asthma, cystic fibrosis and fibromyalgia.

Immune cells require sufficient energy to function, while micro and macronutrients maintain the immune response. Although the immunological function of specific nutrients such as vitamins, minerals and fiber has been assessed in previous research, the immune benefits of specific foods have not been investigated. In this review, the research team aims to address this gap by documenting commonly available foods that can boost immunity and build resistance to disease.

Immune system and nutrition

In humans, the immune response mainly results from active immunity, in which antibodies are produced in the body. In addition to immune cells, other components include physical barriers such as the skin, physiological barriers such as saliva and stomach acid, and complement proteins.

Antibodies or immunoglobulins, which are produced as a result of exposure to pathogens, are classified as immunoglobulins A (IgA), D (IgD), E (IgE), G (IgG) and M (IgM). T and B lymphocytes, such as suppressor T cells, killer T cells, and helper T cells, play an important role in identifying, attacking, and eliminating pathogens. Organs such as the spleen filter infections and abnormal cells in the blood, while glands can trap germs and other foreign material.

Healthy lifestyle choices such as eating a nutritious diet, following a regular sleep schedule, minimizing stress and avoiding unhealthy habits such as smoking can boost immunity and reduce the risk of certain conditions.

In addition to plant and animal foods, water plays a crucial role in strengthening immunity. Staying hydrated keeps mucous membranes moist, cells stay oxygenated, and various systems continue to function. Toxins are carried to the kidneys and then to the urinary tract before being expelled from the body, while dehydration can cause them to build up in the body and cause disease. Drinking adequate amounts of water can also prevent urinary tract infections by stopping the formation of kidney stones.

Inadequate consumption of nutrients can weaken the development of the immune system and make the body more vulnerable to allergies, infections and chronic inflammation. This underlines the importance of adequate nutrition for the optimal functioning of the immune system.

The researchers conducted a literature search of major scientific databases such as PubMed, Web of Science and Scopus to identify studies that focused on the immunomodulatory properties of common foods. These include peer-reviewed literature such as research papers, meta-analyses and systematic reviews.

Foods and nutrients that boost immunity

Citrus fruits such as oranges and lemons are rich in vitamin C, which promotes the formation of lymphocytes, strengthens the body’s epithelial barriers and functions as an antioxidant by reacting with free radicals, which can damage the immune system. Other beneficial compounds found in citrus fruits include selenium, dietary fiber, folic acid and flavonoids, which are antioxidant and anti-inflammatory agents.

Papayas contain folic acid, retinol, riboflavin, thiamin, niacin, potassium, iron, fiber and calcium. Carotenoids such as beta-carotene can be converted into vitamin A and enhance the immune response, while retinoic acid promotes the growth of lymphocytes at sites of infection and inflammation in the stomach.

Similarly, kiwifruit also contains vitamin C, K, potassium, carotenoids, fiber and antioxidants; they are anti-inflammatory foods that can reduce the risk of flu. Pomegranate has antiviral properties and can suppress germs such as Listeria, Clostridium and Salmonella, while promoting healthy bacteria such as Lactobacillus and Bifidobacterium.

Indian gooseberries contain a powerful antioxidant called ellagic acid, while almonds are rich in vitamin E. Broccoli is rich in fiber and a number of antioxidants, as well as vitamins A, C and E, phytochemicals such as polyphenols, minerals and vitamins. Ginger is not only a promising immunomodulator, but also improves digestion and improves appetite, which can also be beneficial for the immune system. Garlic, turmeric, onion, mushrooms and tea are also useful foods that can be included in regular diets for a healthier immune system.

The role of animal foods (ASF)

An important characteristic of AVP is that they contain easily digestible and high-quality proteins, essential amino acids and micronutrients. Prolactin, a hormone found in milk, promotes the movement of lymphocytes and thymocytes; Milk also contains immunoglobulins and whey proteins, which stimulate the synthesis of antibodies.

Yogurt is similar in composition to milk, but calcium can be absorbed more efficiently from yogurt than from milk. In addition to protein, vitamins and minerals, eggs contain choline, which breaks down the amino acid homocysteine, which has been linked to cardiovascular disease. Eggs are an affordable source of protein for those who do not have access to legumes and dairy products.

While medications are critical in healing health problems, maintaining a nutritious diet provides a first line of defense against infections and diseases. Including whole foods and beneficial fruits, vegetables, dairy and eggs can reduce the risk of developing several conditions and reduce their severity if they do occur.