Diet for a good immune response

New Covid variants are becoming increasingly infectious – with the Delta variant currently causing worrying surges. This is of particular concern in relation to those who have not yet received both vaccines. 

Vaccination helps – but even when we’ve been vaccinated we nevertheless need to be able to mount a strong immune response. So it’s no less important to support our immune systems, whether or not we’ve had our jabs. 

New research 

New research has recently revealed that consuming a diet high in fruit and vegetables helps reduce a person’s risk of developing severe COVID-19 infection.

Drawing on a study of more than 2,800 frontline doctors and nurses who were at high risk of infection from COVID-19 as a result of their job, the team from Johns Hopkins Bloomberg School of Public Health in Baltimore Maryland studied their diets and their risk and severity of COVID-19 infection.

The study, “Plant-based diets, pescatarian diets and COVID-19 severity: a population-based case-control study in six countries“, was published in the BMJ Nutrition Prevention & Health journal.

In this new study, the researchers examined three diets:- 

  • plant-based – a diet that contained a higher proportion of vegetables than meat
  • pescatarian – a diet of fish with a high proportion of vegetables
  • low-carb, high-protein diet.

The study authors identified medical front-liners who were working in different countries such as Germany, Spain, Italy, France, the United Kingdom and the United States. Participants involved in the study faced extensive exposure to SARS-CoV-2, the virus that causes COVID-19 infection.

Researchers looked at the diet, medical history and occurrences of COVID-19 among the study participants. They included information on the participants’ personal background and their use of medications and lifestyle.

Among the participants involved in the study, 568 reported they had COVID-19 symptoms or were asymptomatic even though they tested positive for the virus. Another group of 2,316 individuals said they had not had any symptoms – or they had had a negative swab test result.

Of the 568 cases, 138 clinical practitioners reported they experienced moderate to severe COVID-19 infection while the remaining 430 said they experienced very mild to mild symptoms.

The researchers then factored in various variables which included age, medical specialty, ethnicity and lifestyle factors as well as levels of physical activity and smoking.


The researchers found that among those who took part in the survey, those who consumed a diet containing a high proportion of fruit and vegetables had substantially lower chances of COVID infection, compared to those eating a low-carb, high-protein diet – who had four times the chances of developing a moderate to severe COVID-19 infection.


The researchers suggest that a diet that includes a high proportion of vegetables is rich in vitamins, nutrients, and minerals that are essential for a healthy immune system. 

These nutrient-dense foods are essential for mounting an adequate immune response – which in turn can affect vulnerability to COVID-19 infection. Such a diet increases protection from severe COVID-19 complications.

Food For Thought

I’ve been researching and writing on nutrition and health for over four decades. The more I look into the role of individual nutrients, the more astounded I become by nature’s provision for our well-being. Covid has dramatically highlighted the difference in health outcomes that a healthy diet can make – as this study demonstrates.

But a nutrient-dense diet can enhance – not just immunity – but every aspect of health, from the physical to the mental. 

Read more here