In this winter of 2025-26, are you suffering from a series of colds? These infections are not due to chance: an inflammatory diet can be the cause. To remedy this, Julie Boët, dietician-nutritionist, shares with us some “healthy” foods that can effectively support your immune system.
Recurring colds: how to explain them?
When we eat unbalanced – for example during the holiday season – our immune system is damaged. These excesses disrupt the balance of the intestinal flora and affect our ability to fight colds.
“We often underestimate the impact of an inflammatory diet. However, it is among the frequent causes of repeated infections,” confirms Julie Boët. “Indeed, an excess of ultra-processed products, fast sugars, poor quality fats and alcohol maintains low-grade inflammation which unnecessarily mobilizes our immune defenses, thus becoming less effective in the face of attacks such as viruses. she continues.
To this is often added an unbalanced intestinal microbiota. Gold, “approximately 70% of immune cells are found in the intestine”recalls the expert. Result ? When the flora is depleted, the intestinal barrier becomes more permeable… and disrupts the immune response. In other words: we get sick more often and recover less well.
Chronic fatigue also plays a significant role – an exhausted body lacks the energy to produce effective immune cells. “This lack of sleep reduces the production of protective cytokines and antibodies“, says the dietician.
Chronic stress, on the other hand, elevates cortisol, a hormone that, in the long term, decreases immunity. All these factors put together can be enough to weaken the defenses if no good habits are adopted at the same time.
So many arguments which must push us to “eat better“, confirms Julie Boët.
Anti-cold foods to favor
Fruits and vegetables rich in vitamin C
Fruits and vegetables rich in vitamin C, such as citrus fruits, kiwis or peppers, contribute to the proper functioning of white blood cells and the reduction of oxidative stress. “Their effect, however, remains modest if the overall energy intake is insufficient or if the diet lacks proteins, essential for the production of antibodies. recalls the nutrition specialist.
Fermented foods
Fermented foods like yogurt, kefir, raw sauerkraut or miso help nourish the intestinal microbiota. By promoting bacterial diversity, they indirectly strengthen immunity. “But they do not compensate for a diet low in fiber! Without vegetables, fruits, legumes and whole grains to feed these bacteria, their effect remains limited“, emphasizes Julie Boët.
Oily fish
Oily fish, rich in omega-3, play an interesting role in modulating inflammation: by reducing it, they allow the immune system to function more effectively. “Here again, consuming mackerel or sardines occasionally will not be enough if the rest of the diet remains very pro-inflammatory,” specifies the nutritionist.
Garlic, onion and certain spices
Garlic, onion and certain spices such as ginger or turmeric are often highlighted for their anti-microbial and anti-inflammatory properties. “However, even if they can support the body’s defenses, particularly in winter, their impact remains moderate. They do not reverse lack of sleep, nor iron, zinc or vitamin D deficiencies, frequently associated with recurrent infections.” underlines the dietitian.
Proteins
Protein should also have a special place on your plate. “Insufficient intake, common among people who eat little or poorly, directly weakens immunity. And for good reason: eggs, fish, legumes, poultry, tofu and other dairy products provide the amino acids necessary for the production of the body’s defense cells.“, relates the expert. Without these basic nutrients, other so-called “beneficial” foods become ineffective.
Sometimes it also happens that eating better is not enough. Hydration, for example, plays a key role in protecting the respiratory mucous membranes, in the same way as the ambient air breathed.
“Too dry air, combined with insufficient hydration, weakens the respiratory tract and facilitates the entry of viruses“, confesses the practitioner. “Limited exposure to natural light, especially in winter, also promotes vitamin D deficiencies, a nutrient essential to immunity. In some cases, supplementation may be necessary in the form of drops, under supervision. concludes the nutritionist.
Enough to adopt these good anti-cold practices now.