People who eat a Mediterranean-style diet have a lower risk of getting COVID-19, and if they do it's a milder case, large study finds
A large new study suggests eating a high-quality diet rich in vegetables and oily fish may lower your risk of COVID-19, and lead to a less severe case if you were to be infected.
Researchers from Harvard, King's College London, and the research company ZOE looked at data from 592,571 adults in the UK and US involved in the COVID symptom study.
Comparing self-reported COVID-19 symptoms with surveys of participants' eating habits, they found that people who ate the highest quality diets — with Mediterranean-style dishes, full of veggies, grains, nuts, fish, and healthy fats like olive oil — were 10% less likely to get COVID-19.
Those with the healthiest diets were also 40% less likely to become severely ill from the disease than people who ate less nutritious food, according to the June 25 pre-print, which has not been peer-reviewed.
That was true even after accounting for lifestyle factors like mask wearing, exercise, and socioeconomic status.
However, people living in poor communities were most vulnerable to the health risks of a low-quality diet, the data suggests.
Plant-based and Mediterranean
Researchers rated diet quality based on previous research of healthy plant-based diets and UK dietary guidelines.
The healthiest diets, per the study, focused on nutrient-rich whole foods, lots of plants, and few processed foods.
This includes plant-based and pescetarian diets as well as the Mediterranean diet, which research consistently shows to be among the healthiest styles of eating.
The researchers found that people who ate these diets tended to have a healthier gut microbiome, beneficial bacteria in the digestive system. These friendly microbes are associated with many health perks like lower inflammation and better blood sugar control.
Crucially, a healthy gut microbiome is also associated with a lower risk of illnesses including COVID-19.
In contrast, diets were ranked as lower quality if they included more animal products and processed foods, including like juice, potato chips, French fries, refined grains, and added sugars.
Wealth and exercise also play a major role in COVID risk, data suggests
What people eat, and their health as a result, is closely related to other factors, including where they live, and how much money they make.
In this study, participants with a higher-quality diet were more likely to exercise regularly and live in an area linked to more socioeconomic advantages.
However, wealthier people had a lower risk of contracting COVID-19, regardless of their diet.
When people from poorer communities also had a low-quality diet, they were 25% more likely to get COVID-19 than wealthy people with a similar eating habits.