Summer is slowly coming to an end. Our body will soon have to face harsher weather conditions and common winter infections (colds, flu, gastroenteritis, etc.), in addition to COVID-19, which continues to circulate. To best prepare for the cold seasons, it is strongly advised to boost your immune defences. No need to rush to a pharmacy to acquire one of these famous cocktails of vitamins and minerals. There are even more accessible and natural solutions to strengthen your immune system.
These solutions are mainly based on two pillars:diet and physical activity. In other words, taking care of yourself is the guarantee of spending the winter in top form. Certain foods, very rich in vitamin C, should now be included in your daily meals. And while our motivation is generally reduced when the days are gray and cold, it is essential to maintain regular physical activity.
Indeed, it is now proven that physical activity and sports play an important role in the functioning of our immune defences, in particular by stimulating hematopoietic cells, located in the heart of the bone marrow and which produce blood cells, including including lymphocytes. It should be noted, however, that this beneficial effect depends on the intensity of the exercise:some studies maintain that excessively intense training (observed in athletes, for example) can on the contrary lead to immune dysfunction and an increased risk of disease.
However, moderate physical exercise (walking, running, cycling) is still recommended and was quickly proposed as an auxiliary tool in the fight against COVID-19. A 2005 study published in Medicine &Science in Sports &Exercise reports that a 30-minute session of brisk walking significantly increases the production of killer cells (T cells) and various other types of white blood cells.
Similarly, a study involving nearly 1000 participants, followed for 12 weeks in fall/winter, showed that practicing aerobic exercise at least 5 days a week significantly reduced the number and severity of upper respiratory tract infections compared to sedentary people.
Exercising outdoors will be all the more beneficial:exposure to natural light allows the body to synthesize vitamin D – a nutrient that very few foods provide in significant quantities. However, an adequate intake of vitamin D (15 micrograms per day according to ANSES) reduces the risk of viral infection, in particular respiratory infections. Reduced vitamin D levels were also quickly associated with severe forms of COVID-19.
Another behavior to strengthen your immune defenses:eliminate stress. Indeed, chronic stress causes the brain to produce more cortisol, which leads to a number of negative physical effects, including the inhibition of certain immune system responses. Because it also helps to reduce stress, sport is therefore doubly recommended!
On the diet side, it is vitamin C that you will have to hunt:its role in immune function is well established. Vitamin C, for example, supports the epithelial barrier function against pathogens and thus protects the skin against environmental oxidative stress. It accumulates in white blood cells, increasing their power to destroy viruses and bacteria. Vitamin C has also been shown to improve the differentiation and proliferation of B and T lymphocytes, major constituents of our immune defences.
Our body is unable to synthesize this vitamin, so it is food – mainly fruits and vegetables – that allows us to build up reserves. The recommended daily intake is 110 mg for an adult. Among the foods richest in vitamin C:guava, acerola, pepper, papaya, kiwi, orange, mango, Brussels sprouts, parsley, red fruits, etc.
Another food of choice to guard against winter infections:royal jelly, a substance secreted by young nurse bees. Not only does it contain a large amount of vitamins, but also mineral salts and essential fatty acids, which also help boost our immunity, as Total Santé points out.
Finally, note that it is strongly advised to slow down your consumption of alcohol and tobacco, because both weaken our natural defenses. “Alcohol compromises the body’s immune system and increases the risk of adverse health effects. Therefore, people should minimize their alcohol consumption at all times, and especially during the COVID-19 pandemic “, recalled last year the World Health Organization in a press release.
