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Health Three easy ways to boost your defences... and three, not so effective, star productsThe important thing is to 'train' our defences on a daily basis so that they are strong
Friday, 6 February 2026, 16:23
We tend more and more to look for solutions for everything in little bottles.
Perhaps we are becoming lazy or lack confidence in our ability to improve our lives on our own.
That's why the dietary supplement industry for everything - looking better, having energy, gaining physical stamina, boosting sex life, enhancing the brain - is all the rage.
Although the answer to our needs, or the needs we think we have, is often not sold in pharmacies, herbalists or supermarkets, it's right at our fingertips. This happens a lot with all the supplements, substances and nutrients marketed to strengthen the immune system, something that since the pandemic "has become especially important", according to Alfredo Corell, a specialist in immunology, populariser and author of 'Inmunidad en Forma' .
Three star products which are less effective
Dairy product (like Actimel): 'It has beneficial doses of probiotics, although some varieties are very sugary.' That's why Corell recommends yoghurt or kefir instead.
Echinacea: Corell considers it to be an 'harmless supplement.' 'It has very low scientific evidence in the prevention of colds,' he says.
Shiitake, maitake and reishi mushrooms: No significant effects have been observed in healthy people, but there is some efficacy in people with immune problems, although studies are lacking.
In the pandemic, he points out, we became aware that having good defences was what could save our lives in the event of infection: before the vaccine there was little else to do but rely on them, so many of us began to worry about how we would have them (it's not something as verifiable as the state of our hair or our energy level, for example) and to look for ways to reinforce them. "Often at unnecessary expense," says the expert.
Why does he say that? Because, he says, to have a strong immune system you don't have to do strange things or search the internet for compounds or foods that promise wonders. For him, the important thing is to 'train' the defences on a daily basis so that they are strong. He has found that what works best are three, very simple things:
1. A daily probiotic
This simple routine already puts us on the right track, since "the quality of our defences is closely linked to the state of our gut, which acts as a defence barrier against pathogens," he says. And where can we find such beneficial probiotics? The easiest: natural yoghurt and kefir. And, if you dig a little deeper, sauerkraut, kimchi, miso, some cheeses - especially brie, camembert, feta or gorgonzola - and pickles - pickled onions, gherkins... - are also loaded with them.
2. Warning: exercise... moderate!
Numerous studies have shown that physical exercise boosts the immune system, but "if you overdo it, it makes it worse, it increases susceptibility to infections," says the expert, so all those who beat themselves up should be aware that they are not doing themselves any favours on an immunological level. What do we mean by moderate? "It has been shown that during strength training, substances are released that increase the immune system and cardio increases endorphins and reduces cortisol (the so-called stress hormone, and stress is one of the enemies of the immune system).
"It has been known for decades that fit people have lower rates of respiratory infections, for example. And not only that, when they do get sick, they tend to suffer less severe symptoms: this is what researchers call the 'vaccine effect', which has been studied in the context of covid," says Corell. As he explains, in the pandemic it was found that those who exercised regularly had a 36 per cent lower risk of hospitalisation and a 43 per cent lower risk of death.
"Even those who did little exercise were more protected than those who did none," he says. The researchers believe that sport helps increase the circulation of immune cells and releases signalling proteins (cytokines) that guide immune cells towards infections. More benefits? Physical activity is associated with less chronic inflammation, which improves our chances of fighting infections, and enhances the effects of vaccines (they maintain antibodies longer).
3. Sleep habits
If we sleep badly, our defences suffer terribly. That's why maintaining good sleep habits, which means getting seven to eight hours of sleep, is so important for our bodies to be able to respond as well as possible to illness. "Many immune functions follow a circadian pattern, like sleep, which means that their effectiveness and activity varies according to the time of day.
Thus, it is known that defences are primed for increased activity at night, when the body is at rest and can engage in repair and defence. "Insufficient sleep increases susceptibility to infections and even compromises the effectiveness of vaccines," he stresses, recommending that a vaccine should only be given if you have had a good night's sleep for the previous three or four days.