How to naturally support your immune system?

- The skin is a mechanical, chemical (the skin is "hostile" to microbes with a slightly acidic surface), and biological barrier.
- The mucous membranes, more sensitive, have developed an additional means of defence: mucus.
- The respiratory tract allows micro-organisms through, but has defence mechanisms such as coughing to expel them.

The role of inflammation is to slow down and contain the infection.
- Vasodilation increases blood flow so that agents such as phagocytes can reach the site more quickly.
- Phagocytes identify foreign substances and absorb them, without having specific receptors for an antigen like T or B lymphocytes. Other white blood cells of the innate immune system, such as natural killer lymphocytes, can recognise cells infected by certain viruses and destroy them.
- Other white blood cells such as basophils release cytokines, which are involved in inflammation. Cytokines help stimulate and restart the destruction process carried out by macrophages.

It stimulates the production of white blood cells and the production of antibodies by B lymphocytes.
Where to find it? In butter, egg yolk and dairy products. (Or in the cod liver oil our grandmothers used to take!)

Vitamin C is an antioxidant that helps support the immune system and limit oxidation of immune system cells. It also contributes to iron absorption.

Where to find it? In yellow or red peppers, parsley, lemon, blackcurrants, kiwi, broccoli…

Zinc plays an important role in immune response.

Where to find it? In oysters (the food with the highest content), beef, sesame seeds, and in smaller quantities in wheat germ, walnuts, pumpkin seeds, shiitake mushrooms and legumes. 

Prioritise dietary intake, as adverse effects can occur with high doses of zinc through supplementation.

The gut flora contains nearly 100 billion micro-organisms, which play a role in digestion and immune defence by blocking the arrival and colonisation of pathogens on the intestinal wall. This is known as the "barrier" effect of the gut flora.

Each probiotic strain has specific and complementary properties. These include lactic acid bacteria such as lactobacilli or bifidobacteria, as well as live brewer's yeast.

Studies have shown that lactic acid bacteria may also stimulate immune cells to produce antibodies in the case of respiratory infections or flu-like conditions, particularly in children and older people.

A Finnish study from 2001 involving 700 children showed that a Lactobacillus supplement provided a slight but nonetheless significant protection against respiratory infections.

Where can you find them? You can take blends of bacteria containing more than 3 billion bacteria per gram, with at least 5 billion per day, for 2–3 weeks.
Don't forget to eat lacto-fermented vegetables such as sauerkraut!

Vitamin D is thought to play an important role in activating immunity, by increasing the activity of macrophages and an antimicrobial molecule. A vitamin D deficiency is associated with greater susceptibility to infections.

Where to find it? In winter, to top up your vitamin D levels, go outside and expose your face and forearms to the sun for around 15 minutes. Vitamin D produced by the skin has a half-life approximately twice as long as vitamin D that is ingested. 

The foods richest in vitamin D are fish liver oils, and oily fish such as sardines, herring, and salmon. Eggs, milk, and butter also contain it, but in smaller quantities.

In certain situations, your doctor may prescribe a vitamin supplement.

Garlic has traditionally been used to help fight viral infections. It contains compounds with antioxidant and anti-inflammatory properties.

In a 2012 study of 120 adults, researchers showed that garlic could have a positive effect on the immune system in winter. They administered a garlic powder dietary supplement to 50% of participants, while the other half received a placebo. After 45 days of supplementation, patients who received garlic showed a significant increase in the activity of certain lymphocytes. After 3 months of supplementation, both groups were affected by winter viruses, but those taking garlic experienced symptoms 20% milder than the placebo group.

How to consume it? You can add 1 to 4 cloves of garlic per day to your diet, or take it in capsule form if you really don't like the taste!

Elderberries are very rich in vitamins and minerals such as vitamin C, calcium, magnesium, iron, and zinc. High in polyphenols, they act as a powerful antioxidant. They may help support the immune system when it is challenged by a viral infection.

A 2004 American study of 60 flu patients showed that those who took an elderberry syrup within 48 hours of symptoms appearing experienced a reduction in both the duration of the flu and the severity of their symptoms. 

How to take it? As a syrup, 500 mg three times a day for a few days.

Neither royal jelly nor honey, propolis comes from the resins of certain trees collected by bees, which then mix them with their saliva to seal and protect the hive from external threats and keep it clean. It contains resins (50%), essential oils (7%) and wax. It also contains vitamins, flavonoids and antioxidants from the polyphenol family.

Propolis is thought to be particularly effective in managing respiratory infections. Flavonoids may be capable of inhibiting the enzyme responsible for viral proliferation. 

How to use it? It is advisable to choose organic propolis, free from heavy metals and pesticides. Brown propolis is recommended, in the form of hydroalcoholic extracts, powder or mixed with honey. Do not forget other hive products such as royal jelly or pollen.