THURSDAY, Aug. 22, 2024 (HealthDay News) -- COVID cases have surged this summer, but a new study suggests that following the Mediterranean diet might spare you from infection.

In a review published Wednesday in the journal PLOS One, Indonesian researchers discovered that the healthy eating regimen, which centers on fruits, vegetables, whole grains, legumes, fish and heart-healthy fats like olive oil and nuts, lowered the risk of COVID infection.

“There have been numerous studies that heavily associated COVID-19 with inflammation [in the body], while the Mediterranean diet has been long known for its anti-inflammatory properties,” senior study author Andre Siahaan, a lecturer at the Center of Evidence-Based Medicine at the University of North Sumatra in Indonesia, told CNN. “Through our study, we reported a link that further strengthened the connection between these two, in line with our hypothesis.”

“We are aware that changing someone’s diet may not be easy, however, slowly adjusting and incorporating the Mediterranean diet elements one by one into your life would be a good idea,” Siahaan added.

One expert applauded the findings.

“These results could have significant public health implications, underscoring the importance of optimal nutrition in preventing both communicable and noncommunicable diseases,” Dr. Jordi Merino, an associate professor at the Novo Nordisk Foundation Center for Basic Metabolic Research at the University of Copenhagen in Denmark, told CNN.

To investigate whether the risk of infection and severity of disease may be altered by the Mediterranean diet, the team reviewed six studies with more than 55,400 participants from five countries that were published between 2020 and 2023.

To determine COVID cases, four studies relied on participants’ reports of whether they had been infected, while another study identified cases by both self-reports and tests for antibodies. All studies with findings on symptom severity were also based on participants’ memories.

What did they find?

Three studies showed a “significant” association between the Mediterranean diet and reduced risk of COVID infection, while two other studies showed nonsignificant results. Across all the studies, people following the Mediterranean diet had a lower risk of infection, Siahaan said.

Whether the diet could guard against severe disease wasn't as clear, the authors noted.

Only one study reported a significant link between greater adherence to the Mediterranean diet and fewer COVID symptoms, while three others found a nonsignificant relationship. Meanwhile, one study found the diet reduced the likelihood of severe COVID, while two others had inconsistent findings.

The review provides only preliminary insights, Merino added, because there were shortcomings in the research.

Those include that all the studies were observational, so the results don’t prove the Mediterranean diet directly protects against COVID, said Lisa Drayer, a nutritionist, author and CNN health and nutrition contributor.

“This is a big limitation in nutrition research, as it only looks at associations between lifestyle factors and health outcomes,” Drayer told CNN. “Factors other than diet, but associated with the Mediterranean diet, could play a role in the findings.”

Many of the studies in the review didn’t take these factors, which include obesity, diabetes and social disparities, into account, Merino said. The interplay between these things “is complex and cannot be fully understood in isolation,” he added.

Not only that, but the self-reporting of COVID infection is prone to inaccurate memory of what someone ate or how much they consumed certain foods, according to the study.

Last but not least, the level of exposure to COVID wasn’t measured in the studies and that can determine infection risk, Drayer said, “much more so than diet.”

Most importantly, getting vaccinated remains the best protection against COVID-related hospitalization, long-term health outcomes and death, according to the U.S. Centers for Disease Control and Prevention.

More information

The CDC has more on COVID-19.

SOURCE: PLOS One, Aug. 21, 2024; CNN