A healthy diet has long been hailed by some experts as one potentially important factor influencing the risk of Covid-19, or how bad someone’s case gets.
But a team of researchers in Indonesia looked into how a specific lifestyle might affect these odds — finding that following the Mediterranean diet may reduce your risk of getting Covid-19, according to a review published Wednesday in the journal PLOS One.
Participants reported their adherence to the Mediterranean diet using questionnaires.
Three studies found a “significant” association between the Mediterranean diet and reduced risk of coronavirus infection, while two other studies showed nonsignificant results.
“Factors other than diet, but associated with the Mediterranean diet, could play a role in the findings.” These aspects that can affect the results if not controlled for are known as confounding factors.
Improving diet for disease risk While short-term dietary changes may have a limited impact on the risk of Covid-19, the long-term benefits of a sustained healthy diet could be larger, Merino said.
Regardless of how protective the Mediterranean diet may be against getting Covid-19 or developing severe symptoms, it’s “a healthy and delicious lifestyle choice” that Drayer recommends and follows herself, she said.
“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,” said Siahaan, the senior author.
Long praised by some experts as one potentially significant factor influencing a person’s risk of contracting Covid-19, or how severe their case becomes, is a healthy diet.
A review published in the journal PLOS One on Wednesday suggests that eating a Mediterranean diet may lower your risk of contracting Covid-19. The researchers in Indonesia investigated how a particular lifestyle might affect these odds.
The review’s senior author, Andre Siahaan, a lecturer and member of the Center of Evidence-Based Medicine at the University of North Sumatra in Indonesia, wrote via email, “There have been numerous studies that heavily associate COVID-19 with inflammation (in the body), while the Mediterranean diet has been long-known for its anti-inflammatory properties.”. As predicted by our hypothesis, we found a link through our study that further solidified the relationship between these two. “.
Covid-19’s onset and severity have both been linked to inflammation.
The World Health Organization states that since the coronavirus outbreak in 2019, there have been over 775 million documented cases of infection. According to the most recent data from the WHO, that number is still rising, with over 47,000 cases recorded in the week preceding August 4. With COVID-19, over 7 million people have lost their lives.
In order to examine if the Mediterranean diet may reduce the risk and severity of infection, the team examined six studies published between 2020 and 2023, totaling over 55,400 participants from five different countries. Participants used questionnaires to report how closely they followed the Mediterranean diet.
While one study used both self-reports and antibody tests to identify cases, four other studies used participant reports to determine the number of Covid-19 cases. Every study that reported on the severity of the symptoms also relied on the participants’ memories.
While two other studies produced nonsignificant results, three studies found a “significant” correlation between a Mediterranean diet and a lower risk of contracting coronavirus infection. The Mediterranean diet was associated with a lower risk of infection in all of these studies’ subjects; however, Siahaan noted that the variation in significance across studies makes it difficult to accurately pin down this risk.
However, it’s unclear if the diet could also lessen the severity of the illness or its number of symptoms, according to the authors, who rated the evidence for these areas as “low certainty.”. “.
Three studies found no significant relationship between reduced Covid-19 symptoms and increased adherence to the Mediterranean diet, while only one study found a significant correlation. Two studies produced contradictory results, but one concluded that the diet decreased the risk of severe Covid-19.
Higher consumption of nuts, fruit, and olive oil; lower consumption of cereal and red meat; and moderate alcohol intake were the food categories measured in some studies that were linked to a lower risk of coronavirus infection. Consuming more fruits, vegetables, nuts, legumes, fish, whole grains, and legumes has been associated with a decreased risk of severe Covid-19.
Dr. Jordi Merino, an associate professor at the University of Copenhagen’s Novo Nordisk Foundation Center for Basic Metabolic Research, stated, “These results could have significant public health implications, underscoring the importance of optimal nutrition in preventing both communicable and noncommunicable diseases.”. Merino did not contribute to the review.
Unanswered questions.
Merino stated that since the review offers only preliminary insights, significant flaws that compromise the validity of the results should be taken into consideration.
Lisa Drayer, a nutritionist, author, and contributor to CNN’s health and nutrition section, who was not involved in the review, cited a number of these, including the fact that all of the studies were observational and that the results provide correlations rather than conclusive evidence about the protective effects of the Mediterranean diet against Covid-19.
Through email, Drayer stated, “This is a big limitation in nutrition research, as it only looks at associations between lifestyle factors and health outcomes.”. The results may be explained by variables unrelated to nutrition but connected to the Mediterranean diet. “.
Confounding variables are those characteristics that, if they are not taken into account, may have an impact on the outcomes. These were overlooked in a large number of the studies, which may have affected the conclusions regarding the diet’s efficacy. These include vital elements that have been shown to increase the risk and severity of Covid-19, like diabetes, obesity, and socioeconomic determinants of health like access to wholesome food, according to Merino. According to Merino, the interactions between these elements “are complex and cannot be fully understood in isolation.”.
The authors stated that “two studies that adjusted for confounding factors reported non-significant association, while the studies that did not adjust for confounding factors reported significant association.”.
Furthermore, the study found that biased responses, such as a false memory of what ate or how much of a particular food was consumed, are common when people self-report health information (in this case, diet history and Covid-19).
A person’s risk of infection is also greatly influenced by exposure to Covid-19, which was not assessed in the studies, according to Drayer. This factor is “much more so than diet.”. “.
The authors stated that additional study is required in order to reach firm conclusions because of these unresolved issues.
enhancing nutrition to lower disease risk.
According to Merino, the long-term advantages of a consistent healthy diet may outweigh the short-term benefits of dietary modifications, which may have little effect on the risk of Covid-19.
The Columbia Vagelos College of Physicians and Surgeons assistant professor of clinical medicine, Dr. Sara Seidelmann, wrote in an email that “these foods are rich in antioxidants, fiber, and micronutrients that enhance immune function and may help boost our natural microbiome and reduce inflammation.”.
Drayer described the Mediterranean diet as “a healthy and delicious lifestyle choice” and said she personally adheres to it, regardless of how effective it may be at preventing Covid-19 or severe symptoms.
Additionally, studies have shown that the Mediterranean diet may help lower the incidence or severity of heart disease, stroke, dementia, breast cancer, high cholesterol, memory loss, depression, and other conditions.
“We understand that altering one’s diet may not be simple, but it would be wise to gradually make changes and integrate each component of the Mediterranean diet into your daily routine,” stated senior author Siahaan.
Seidelmann stated that while lowering red meats and processed foods, these include fruits, vegetables, whole grains, legumes, nuts, fish, and olive oil.
But above all, according to the US Centers for Disease Control and Prevention, vaccination “remains the best” and safest defense against hospitalization, long-term health consequences, and death linked to Covid-19.
“By adopting healthy dietary practices and addressing underlying health disparities, we can enhance population resilience and improve overall health outcomes,” Merino said, adding tactics like vaccination and mask use to the mix.
