Can a good diet help prevent you from catching COVID-19?

Dr Joan Ransley

As winter approaches, COVID-19 and other respiratory infections are likely to become more common. It is almost three years since the start of the pandemic, but the virus still has not gone away. Now research findings are pointing to the crucial role diet plays in your chance of catching and becoming seriously ill with this disease.

Does diet have an impact on helping to prevent catching COVID-19?

Studies have shown people who eat the ‘highest quality diet’ are about 10% less likely to develop COVID 19 than those with a poor diet. Those with a good quality diet are also 40% less likely to get severe COVID-19 requiring treatment in hospital regardless of age, ethnicity, socioeconomic status, gender.

What foods are included in a high-quality diet?

The sort of diet that can help protect you from catching COVID-19 is rich in plant foods such as fruits, vegetables, wholegrains, nuts and seeds. Oily fish and, fermented foods such as live yogurt, kimchi and unpasteurised cheese have also been shown to improve the quality of the diet.

Can this sort of diet help recovery from COVID-19?

Research has also shown a plant-based diet containing oily fish and fermented foods can help your recovery if you have caught COVID-19.

What is diet quality?

Scientists have found is that it is not single food that help to build up your immune system and help to protect you from catching COVID-19 but ‘diet quality’ that is an important factor.

Diet quality is a term used by nutritionists to describe the overall pattern of an individual’s food intake over weeks and months.

Why does what we eat help to protect against infections?

What we eat has a major effect on our overall health. Eating a good quality diet can help people to keep a healthy weight. Being overweight is a major risk factor for catching and becoming ill with COVID-19.

The food we eat also has a major impact on our gut microbiome (bugs in our gut) and our immune system. Having a healthy gut microbiome is key to having a healthy immune system.

What are the best ways to improve the quality of the diet?

1. Keep ultra-processed foods and sweetened drinks to a minimum. On average in the UK, ultra-processed food makes up over 50% of our shopping baskets. These foods often bear little resemblance to foods found in nature. They are often high in fat, salt and added sugar, and depleted in dietary fibre. Think cakes, biscuits, snacks, and fried, fast food.
2. Include plenty of the following foods in your diet:

• • Vegetables. They contain fibre, minerals and vitamins that help to support your immune system.
  • Fruit. Whole fruit is naturally sweet and is packed with nutrients that are good for your health.
  • Wholegrains including, oats, brown rice, pearl barley, buckwheat. They all contain plenty of fibre and complex starches that are good for healthy gut bacteria.
  • Oily fish including, salmon, mackerel and sardines. They are high in omega-3 fats, which are essential for our health. Aside from these healthy fats, fish contain important nutrients, including iodine, iron, selenium, vitamin B2, vitamin D, and zinc.
  • Fermented foods including kefir, kimchi, sauerkraut, live yogurt. These foods increase the quantity and diversity of the trillions of microbes in the gut microbiome. A healthy gut microbiome supports your immune system, helping you fight off infections, including COVID-19.

What to eat if you have COVID-19

If you have COVID-19, it’s important that you top up your fluid levels and stay hydrated as the body uses a lot of water if it is fighting an infection. Eat plenty of nutritious high energy food from the lists above. Eating smaller meals or snacks throughout the day may be easier than eating big meals.