You don’t need to be an expert to know that eating more plants is good for you. There’s a reason why we’re always being told to aim for those magical ‘five a day’ and ‘30 plants a week’ targets – the fibre and nutrients in our leafy and colourful friends help our body to function properly.

And, according to a new study published in BMJ Nutrition, Prevention & Health, plants may play a significant role when it comes to our immune systems. It found that people who follow predominantly plant-focused vegetarian or vegan diets are 39% less likely to catch Covid-19 than those who consume plenty of meat and dairy. 

The study, which took place between March and July 2022, involved 702 adult volunteers who were surveyed on their eating patterns and how frequently they ate different food groups, as well as their lifestyle and medical history. They were then divided into two groups: omnivores (those who ate meat and dairy frequently alongside plants) and what they called ‘plant-based’ (those who ate little to no meat or dairy). The second group was further divided into flexitarians (people who ate meat three or fewer times a week), vegetarians and vegans.

From March to July, 330 people in the study contracted Covid-19. Before considering any medical conditions or pre-existing risk factors, the omnivore group still had a significantly higher incidence of infection compared to the plant-based group, at 52% v 40%. But after accounting for those potentially influential factors – such as weight and physical activity levels – those following a predominantly plant-based or vegetarian/vegan diet were still 39% less likely to become infected than the omnivores who took part.

The results suggest that a diet high in plant products – fruit, vegetables, legumes, grains, nuts and seeds – could protect against Covid-19 infection.     

According to the study’s authors: “Plant-based dietary patterns are rich in antioxidants, phytosterols and polyphenols, which positively affect several cell types implicated in the immune function and exhibit direct antiviral properties.”

Now, it’s worth noting that this study was entirely observational, meaning the researchers did not measure the impact of the diets on the participants, but it still adds to pre-existing research that suggests eating more plants could have a positive impact on immune health. 

Not only do we know that the nutrients in plants are fantastic for supporting our immune system, but we also know that eating more plants can support a diverse and healthy gut microbiome, which research has shown to be directly linked to immunity.  

We know that up to 80% of the immune system is in the gut, a figure based on the surface area of the gut versus that of the skin, respiratory system and reproductive systems, which all help to protect us from unwanted pathogens. “The gut is a literal barrier to the outside world,” nutritional therapist Marjolein Dutry van Haeften previously told Strong Women. “The entire lining of the gut (from the mouth all the way down the intestinal tract) is lined with a mucosal layer that functions to protect us from viruses, bacteria and fungi.

“Our microbiome and body work together to recognise disease-causing agents and set them apart from harmless foreign material.”

So, if you want to protect yourself from any unwelcome bugs this winter, then upping the number of plants in your diet (as well as reducing your reliance on meat and dairy) is a great place to start. It doesn’t have to be difficult – you can count legumes, grains, nuts and seeds among your daily plant intake and incorporate lots of fresh herbs and spices to add variety.  

Images: Getty