Food Allies for the Best Immune System

Living a healthy lifestyle and properly nourishing your microbiota are the best strategies for promoting overall health and fighting off external invaders like viruses.

What is the Immune System?

The immune system defends the body against infection and disease. To do so, it has an impressive array of cells and organs that work as a team. These include antibodies, white blood cells (lymphocytes), bone marrow and the lymphatic system (e.g. spleen, lymph nodes, tonsils).

Even the skin and mucous membranes of the nose and mouth are part of our first line of defence, whose role is to prevent unwanted intruders from entering our body. When external invaders, such as the flu virus or pathogenic bacteria (e.g. salmonella), unfortunately manage to get past this first barrier of protection, the immune system activates other lines of defence to protect the body.

The Foundation of Good Immunity: A Diverse and Sufficient Diet

The immune system needs a lot of energy to function, and even more when we are sick or have to fight "enemies". Therefore, the first strategy to properly fuel our immune system is to eat enough to avoid running out of energy, and to opt for a healthy and varied diet to avoid nutritional deficiencies.

What's even better is that a winning diet is also good for the microbiota [1], which works in concert with the immune system. This is fascinating and logical since approximately 70% of our immune system is found in the gut! In fact, the gut acts as a barrier to prevent intruders from invading our bloodstream. As a result, gut health plays a big role in maintaining a healthy immune system.

It has been shown that our diet can enrich or deplete the quality and variety of bacteria that inhabit our digestive system, i.e. our intestines. For example, a diet composed of an abundance of fibre from plants such as legumes (e.g. lentils, chickpeas, lupins), nuts and seeds, fruits, vegetables and whole grains (quinoa, brown rice, buckwheat) is positively associated with the growth of bacterial populations favorable to microbiota health [2].

Therefore, a diet based on the recommendations of Canada's Food Guide Balanced Plate is optimal for maximizing overall health and immunity.

Conversely, a diet low in fibre and high in fat, animal protein and sugar stimulates the growth of less beneficial bacteria and contributes to the deterioration of good bacteria populations, unbalancing the microbiota.

Good to know!

When people who are deficient in these nutrients are supplemented with zinc, vitamin A or C, for example, we see an improvement in the immune response, which becomes more "normal". On the other hand, supplementing people who do not suffer from nutritional deficiencies cannot further strengthen the defense mechanisms. [1]

Source : https://ods.od.nih.gov/News/The_Scoop_-_Summer_2020.aspx

The Key Role of Certain Nutrients on the Immune System

Vitamin A

Vitamin A is essential for maintaining healthy skin and mucous membranes, which are the physical barriers of our first line of defence.

Sources: organ meats, egg yolk, milk, orange and dark green vegetables (e.g. carrots, sweet potatoes, kale, spinach).

Vitamin D

Vitamin D plays a crucial role in activating the immune system's defences. For example, T-cells need vitamin D to better fight viruses and bacteria. In addition, vitamin D helps maintain the integrity of the intestinal mucosa, preventing pathogens from crossing the intestinal barrier.

In addition, vitamin D helps maintain the integrity of the intestinal mucosa, preventing pathogens from crossing the intestinal barrier.

Sources: Vitamin D is synthesized by the skin under the effect of the sun's rays and is rarely found in the diet (fatty fish, egg yolk, cod liver oil, fortified milk). This is why it is recommended to take a vitamin D supplement as soon as the leaves fall in the fall and until the end of winter. The recommended dose for adults varies between 400 IU and 2000 IU per day. To find the dose of vitamin D supplement that is right for you, it is always a good idea to talk to your doctor or health care professional.

Probiotics

Probiotics are live microorganisms that, when ingested in sufficient quantities, contribute to a balanced microbiota and have positive effects on health. Specifically, by supporting our good gut bacteria to do their job well, probiotics can have benefits on digestion and the immune system.

Sources: Probiotics are found naturally in fermented foods and beverages such as sauerkraut, kefir, kombucha, tempeh and Korean kimchi. They are also available in supplement form.

Proteins

Antibodies are proteins released by white blood cells, called b-lymphocytes. Their role is to detect all foreign bodies entering the body. This is why proteins are essential to the proper functioning of the immune system.

Sources: Since proteins from plants promote a healthy microbiota, they are to be preferred: legumes, tofu, tempeh, edamame, nuts and seeds. Note that most of these plant protein sources are also rich in magnesium, a mineral known for its important role in the proper functioning of immunity.

Always be sure to seek the advice of your physician or other health care professional with any questions regarding a medical condition.