Does the Mediterranean diet lessen the likelihood of contracting Covid-19? Authoritative voices share their perspectives.
A group of researchers in Indonesia examined how a certain lifestyle could influence the chances of contracting COVID-19. They discovered that following the Mediterranean diet might decrease your likelihood of contracting COVID-19, as mentioned in a study published on Wednesday in the journal PLOS One.
As Andre Siahaan, the study's senior author and a lecturer at the University of North Sumatra's Center of Evidence-Based Medicine in Indonesia, put it in an email, "There have been numerous studies which indicate a strong link between COVID-19 and inflammation in the body. On the other hand, the Mediterranean diet is well-known for its anti-inflammatory properties. Our study supports a connection between the two, aligning with our hypothesis."
Inflammation has been associated with both the emergence and severity of COVID-19.
Since the coronavirus outbreak in 2019, there have been over 775 million reported cases of infection worldwide, as reported by the World Health Organization. This number continues to climb, with over 47,000 new cases reported in the week leading up to August 4 — the latest statistics from the WHO. The death toll from COVID-19 now stands at over 7 million.
To investigate whether the risk of infection and severity might be reduced by following the Mediterranean diet, researchers reviewed six studies containing over 55,400 participants from five different countries. Participants reported their adherence to the Mediterranean diet using questionnaires.
Three of these studies concluded that there was a "significant" link between the Mediterranean diet and a lower risk of contracting COVID-19, while two others produced non-significant findings. In total, participants who followed the Mediterranean diet had a lower risk of infection. However, the authors noted that this risk reduction cannot be accurately quantified due to the differing levels of significance across studies.
As for whether the diet could also reduce the number of symptoms or the severity of the disease, the evidence is less clear. According to the authors, the evidence is graded as "low certainty" in this regard.
Only one study reported a "significant" link between greater adherence to the Mediterranean diet and fewer COVID-19 symptoms, while three others did not find a significant relationship. One study found that the diet reduced the likelihood of severe COVID-19, but two others showed inconsistent results.
Among the food categories analyzed in some studies, a higher consumption of olive oil, fruit, and nuts; a lower consumption of cereals and red meat; and a moderate intake of alcohol were associated with a lower risk of contracting COVID-19. Eating more vegetables, fruits, legumes, nuts, fish, and whole grains was linked with a lower risk of severe COVID-19.
"These results could have significant public health implications, highlighting the importance of proper nutrition in preventing both communicable and non-communicable diseases," said Dr. Jordi Merino, an associate professor at the Novo Nordisk Foundation Center for Basic Metabolic Research at the University of Copenhagen in Denmark. Merino was not involved in the study.
Unanswered questions
The study presents preliminary findings, Merino added, so potential weaknesses that could impact the reliability of the results should be considered.
These weaknesses include the fact that all studies were observational, meaning they provide correlations but do not prove that the Mediterranean diet does or does not have a protective effect against COVID-19. "This is a significant limitation in nutrition research, as it only examines associations between lifestyle factors and health outcomes," Merino said. "Factors other than diet, but connected to the Mediterranean diet, could play a role in the findings."
These confounding factors, which were not accounted for in many studies, could have influenced findings regarding the effectiveness of the diet. Examples of confounding factors include well-established contributors to the risk of contracting COVID-19, such as obesity and diabetes, as well as social determinants of health, including access to healthy food. Merino noted that the interplay between these factors is complex and cannot be fully understood in isolation.
"The studies that did not account for confounding factors reported significant associations, while two studies that did account for confounding factors reported non-significant associations," the authors wrote.
Furthermore, the self-reporting of health information, such as COVID-19 and diet history, is susceptible to biased responses, such as inaccurate recollections of food consumption. Exposure to COVID-19, which was not measured in the studies, is another significant factor in determining a person's risk of infection.
Given these uncertainties, more research is required before definitive conclusions can be drawn.
Improving diet for disease risk
While short-term diet changes may have limited impact on the risk of contracting COVID-19, the long-term benefits of a sustained healthy diet could be more substantial, Merino said.
"These foods are rich in antioxidants, fiber, and micronutrients that boost immune function, and may help our natural microbiome and reduce inflammation," said Dr. Sara Seidelmann, an assistant professor of clinical medicine at Columbia University's Vagelos College of Physicians and Surgeons.
Regardless of its potential protective effects against COVID-19 or severe symptoms, the Mediterranean diet is "a healthy and delicious lifestyle choice" that Merino recommends and follows herself.
The Mediterranean eating plan has shown benefits in reducing or lessening the threat of issues like heart disease, strokes, dementia, breast cancer, high cholesterol, memory loss, depression and other matters.
Siahaan, the main researcher, stated, "Altering someone's diet might not be straightforward, but gradually introducing Mediterranean diet components into your life is a sensible approach."
These components include fruits, veggies, whole grains, legumes, nuts, fish, and olive oil, while cutting back on red meats and processed foods, as Seidelmann pointed out.
However, it's crucial to note that getting vaccinated is still "the most effective" and secure way to prevent Covid-19-related hospitalization, long-term health complications, and death, according to the American Centers for Disease Control.
Beyond methods like vaccination and mask-wearing, "by embracing healthy dietary habits and tackling underlying health disparities, we can strengthen population resilience and boost overall health outcomes," Merino suggested.
Following the Mediterranean diet could potentially reduce the risk of experiencing severe COVID-19 symptoms due to its anti-inflammatory properties, as suggested by the study's findings. Adhering to this diet has been linked to various health benefits, including reducing the risk of conditions like heart disease and breast cancer.
