We are going through a strange period, that of Covid-19, and more and more people are desperately looking for “remedies” and magic foods to protect themselves. In this article we will find out if, after all, diet can help boost our immune system.
The immune system needs to be constantly alert for any signs of invasion or danger. More specifically, immune cells need to be able to distinguish themselves from the foreign invader as well as to distinguish harmful from non-harmful molecules.
It is the microbiota that contributes significantly to the training and regulation of the immune system. It is therefore considered vital to achieve and maintain a healthy intestinal flora with the help of a proper nutritional model. Before proceeding , it is appropriate to mention the factors that can reduce- diminish the function of the immune system in the first place.
Which factors can reduce our immune system:
With the passage of years, the internal organs begin to wear out and become less and less functional as a result. Organs associated with the immune system such as the thymus gland or bone marrow produce fewer immune cells needed to fight infections.
Environmental toxins (tobacco, excessive alcohol)
These substances can damage or suppress normal immune cell activity.
Obesity is associated with chronic low-grade inflammation. More specifically, it has been identified as an independent risk factor for the influenza virus, probably due to reduced function of T-cells, a type of white blood cell.
In line with the previous factor, a poor diet rich in processed foods and deficient in nutrients and malnutrition can affect the production and activity of immune cells and antibodies.
Autoimmune disorders and immunodeficiencies attack and possibly deactivate immune cells resulting in the gradual destruction of the body’s defences.
Chronic mental stress
Stress releases hormones such as cortisol that suppresses inflammation (inflammation is initially required for immune cell activation) and white blood cell activity.
Lack of sleep
Sleep is a recovery period for the body, during which a type of cytokine is released to fight any infections. A small amount or frequency of sleep reduces the amount of these cytokines and other immune cells.
Researchers have concluded that there are a number of micro and macronutrients which, rather than being incorporated into the diet, can contribute to the overall well-being of the immune system. More specifically, there are certain dietary patterns that can better prepare the body for microbial attack and inflammation, but it is unlikely that foods in isolation will offer specific protection. This is because each stage of the body’s immune response relies on the presence of many micronutrients at the same time. Examples of nutrients that have been identified as critical for immune cell development and function include probiotics, prebiotics, vitamin C, vitamin D, zinc, selenium, iron and protein, etc.
Prebiotics and Probiotics
Diet plays a big role in determining the types of microbes that live in the gut. A high fibre diet rich in fruits, vegetables, whole grains and legumes seems to support the growth and maintenance of beneficial microbes. Some beneficial microbes break down fibre into short-chain fatty acids, which stimulate immune cell activity. These fibers are called prebiotics because they feed microbes. Therefore, a diet containing probiotic and prebiotic foods can be beneficial. Probiotic foods contain live beneficial bacteria and prebiotic foods contain fibre and oligosaccharides that feed and maintain healthy colonies of these bacteria.
Probiotic foods include kefir, yogurt with live active cultures, fermented vegetables, pickled cabbage, tempeh, kombucha tea, kimchi and miso.
Prebiotic foods include garlic, onions, leeks, asparagus, bananas and seaweed.
Vitamin C is thought to increase the production of white blood cells, which play an important role in fighting infections.
Almost all citrus fruits are high in vitamin C. Oranges and orange juice, red and green peppers, strawberries, gooseberries, kiwi. But apart from citrus fruits, vegetables such as red peppers, broccoli and tomatoes are equally rich in this element.
The design of our immune system is complex and is influenced by the ideal balance of many factors, not just diet, and especially no one particular food or nutrient. “Western” diets that have limited variety and fewer nutrients, while consisting primarily of over-processed foods, can negatively impact a healthy immune system. However, a balanced diet consisting of a range of vitamins and minerals, combined with healthy lifestyle factors such as adequate sleep, exercise and less stress, can help the situation.