A Spanish study – first-of-its-kind in the world – shows for the first time that a healthy eating pattern has a protective effect against SARS-CoV-2 infection
While vaccines continue being administered to Spaniards, diet is becoming the most powerful shield against SARS-CoV-2 – on top of facial masks and social distance. This is addressed by a complete Spanish scientific study – first-of-its-kind in the world–, pending review, which confirms that a strong adherence to the Mediterranean diet reduces the risk of infection by Coronavirus by 64% in comparison with those who have a less healthy lifestyle. “This is the first time we have shown that with a dietary pattern as a whole we are able to reduce vulnerability to the new Coronavirus,” Miguel Ángel Martínez-González affirmed. He is a professor at Harvard University and director of the Department of Preventive Medicine and Public Health at the University of Navarra. He led this work along with the Predimed network of researchers.
To reach this conclusion, in recent months the Martínez-González team has carried out a detailed analysis of roughly 5,000 people participating in the SUN project (Seguimiento Universidad Navarra), a prospective epidemiological cohort study with 93% adherence. “We know all the health details of these people, their medical history and their eating pattern. In this case, out of more than 9,000 individuals, we have excluded health professionals because during the first months of the pandemic they were highly exposed to the virus without appropriate protection measures, potentially altering the results. Thus, through epidemiological models we found that these 5,000 people had a very robust protection from the Mediterranean diet against Coronavirus infection with a clear dose-response effect; in other words, the higher the adherence to this diet, the less likely the infection”, professor Martínez-González pointed out. He revealed that the risk drops by up to 50% when adherence to this diet is moderate, compared to those who do not eat this diet.
Faced with such an overwhelming statistic about protection, it is worth finding out where the secret lies. And Martínez-González is clear about it: “We are not talking about the ‘power’ of a single compound, but about a wholesome diet style that is capable of providing all the nutrients, vitamins and minerals necessary for a good function of the organism, with a great anti-inflammatory and antioxidant potential”. These properties translate into direct effects on the immune system and the inflammatory response “through monounsaturated fatty acids, tocopherols and polyphenols, which the Mediterranean diet abundantly provides; as well as indirect effects, since it is a diet low in saturated fat and has a good linoleic acid/alpha linolenic profile,” said Pablo Suárez, a member of the Nutrition area of the Spanish Society of Endocrinology and Nutrition (SEEN). And this same explanation was ratified by Carmen Martín Alonso, member of the Spanish Immunology Society (SEI), who recognized that, “without a doubt, our immune system is the best weapon we have against Covid-19, and the Mediterranean diet contains everything necessary in adequate proportions for its correct function. Good hydration is also important, especially for older people, since the virus enters through the mucous membranes and if they are not well hydrated from not drinking enough water, we are making it easier for the virus”.
The association between nutrition and the immune system is very complex “and many factors are involved such as vitamins, minerals, the microbiota … The insufficiency of some of these micronutrients, such as zinc or vitamin D, can cause immunological disorders, while “pro-inflammatory” eating patterns are capable of worsening people’s immune capacity and hinder their defense mechanisms against external aggressions,” explained Suárez, who added that “diets high in fiber and prebiotics, such as the Mediterranean diet, have been associated with a decrease in some blood inflammatory parameters, as well as favorable modifications in the gut microbiota, which seem to influence the immune state”.
However, as Suárez warns, “no diet will prevent infection on its own, as this can only be achieved with safe behavior habits, hygiene and vaccines.” Nevertheless, what all the experts agree on is that eating a Mediterranean diet results in a good general health, “since these are people with a lower obesity rate, lower diabetes, cholesterol, and high blood pressure prevalence… In short, their health, thanks to that balanced diet, is much better, and without these underlying conditions the risk of infection and worst-case prognosis of Covid-19 is much lower,” explained Martínez-González.
What should we eat?
With these evidence on the table, it is time to put into practice and find out what this Mediterranean diet should mean in terms of our plates: “Extra virgin olive oil, which is the most characteristic food of this diet, provides most of its immunomodulatory, anti-inflammatory and antioxidant properties through monounsaturated acids, while nuts and fish – also predominant in this diet – provide a large amount of omega-3 fatty acids, which have remarkable anti-inflammatory properties”, Suárez emphasized.
But that is not all, since “vitamins and minerals are very important, and despite being needed in small quantities are essential for the proper functioning of our immune system. Vitamin D is key, and is obtained by consuming vegetable fat (oil, nuts) and exposure to sunlight. Also yogurts and other probiotics, as it has been scientifically proven that they stimulate and strengthen natural immunity, while zinc and selenium, found in meat, whole grains and cheese, are also necessary for the immune system,” said Martín Alonso, who recommended prioritizing fresh and local food.
Foods to Avoid
Almost as important as what we eat is what to avoid eating, since “a diet high in ultra-processed foods worsens the response capacity of the immune system,” said Carmen Martín Alonso. And that means reducing the consumption of “processed cheese and red meat, high in saturated and trans fatty acids, which are capable of promoting a harmful pro-inflammatory state. Furthermore, some studies associate the intake of refined sugar with a decrease in the immune capacity and, therefore, a greater susceptibility to contracting infections”, warned Pablo Suárez. The explanation lies in the fact that “when people overconsume these foods, the defense system is continuously active, the cells of the immune system are compromised and uncontrollable responses can be triggered, in addition to the damage on the walls of veins, promoting thrombi”, Martín Alonso explained.
Date: March 29th, 2021
By Raquel Bonilla
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