BOSTON, Mass. (KSNW and press release) – When it comes to developing COVID-19, what you eat matters, according to a new study by health science company ZOE, Harvard Medical School and King’s College of London.

Researchers analyzed the eating habits of nearly 600,000 study participants in February 2020, before the pandemic. What they found: People with the highest quality diet were around 10% less likely to develop COVID-19 than those with the lowest quality diet and 40% less likely to become severely ill.

“We’ve been noting who, which persons are getting symptoms of COVID, who’s going positive, who’s negative, et cetera, by using a daily symptom app,” professor of epidemiology at King’s College London and co-founder of ZOE, Tim Spector said.

This is the first study to show that a healthy diet cuts the chances of developing the disease in the first place. According to a release, the study’s scale meant researchers were able to adjust for multiple confounding factors.

The study also found those who ate a poorer diet were more at risk, especially if they live in a more socioeconomically-deprived area.

Nutrition does not have to be complicated. Spector recommends aiming to eat 30 plants a week.

“Obviously fruits, vegetables, but also different types of nuts, different kinds of seeds, different kinds of herbs and spices, all these things are important,” Spector said.

Spector recommends berries and fruits rich in color, but also things like coffee, dark chocolate and red wine can be good for your gut. Fermented foods like yogurt, kefir, kombucha, kimchi and sauerkraut can also contribute to a high-quality diet.

“Avoid basically what 60% of calories in America are, which is ultra-processed food. So all the things with multiple additives and chemicals that don’t resemble real food, these are bad for your gut,” Spector said.

Based on the study’s results, the researchers estimate nearly a quarter of COVID-19 cases could have been prevented if these differences in diet quality and socioeconomic status had not existed, according to the release.