The Role of Nutrition in the Immune System

Should we pay more attention? Part I of II

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As the coronavirus (COVID-19) is spreading rapidly across the globe, it is important to take note of the approaches that can help prevent and fight infections, particularly viral infections. Evidence already suggests that viral infections are one of the world’s greatest public health challenges (WHO, 2020). The World Health Organization (WHO) estimates seasonal influenza results in 3-5 million cases annually. Today we understand hygiene and social distancing play a key role in protecting yourself and others from contracting a virus while also slowing the spread of infections. Here are a few simple ways to reduce your risk to infections:

– Wash your hands regularly for 20 seconds with soap and water or alcohol-based hand rub.
– Cover your nose and mouth when you sneeze or cough with a disposable tissue or flexed elbow.
– Avoid close contact with people who are sick.
– Stay at home and self-isolate from others if you feel unwell.

Incorporating nutrition

Good nutrition is fundamental to improving immunity. The immune system is the body’s defense against disease and infection and it has long been established that several factors influence the function of the immune system including stress, sleep and nutrition (Song et al, 2019; Patel et al 2012 and Gombart et al 2020). The WHO guidance on diet, especially during the current pandemic states that “good nutrition is crucial for health, particularly in times when the immune system might need to fight back” (WHO, 2020). Providing a diet high in nutritious foods rich in vitamins and minerals supports optimal function of the immune system by providing antioxidants to slow damage of cells caused by free radicals (Lobo 2010) or assisting in T-cell production (Cohen 2017). 

Although, presently, we do not have data concerning nutritional factors in relation to the risk and severity of viral diseases such as COVID-19 the role of nutrition in immunity has been well established. For example, a study on the role of vitamin A in the treatment of measles in children found a reduced risk of mortality and pneumonia when vitamin A was administered over two days (D’Souza and D’Souza, 2002). The European Journal of Clinical Nutrition concluded that “Without adequate nutrition, the immune system is clearly deprived of the components needed to generate an effective immune response” (Marcos et al, 2003). Good nutrition is thus important in supporting an optimum immune system which can reduce the risk of viral infections (Beck and Levander, 2000).

It is now recognized that the complex, integrated immune system requires several micronutrients that have essential, often synergistic roles at every phase of the immune response (Gombart et al, 2020). In fact, even marginal deficiencies in certain nutrients have been shown to impair the immune system (Gombart et al, 2020). Micronutrients are believed to work collectively to support an optimum immune system. Based on a variety of systematic and clinical data, vitamins AB6, B12C, D, E, folate, zinc, iron, copper, and selenium (read our Vitamin and Mineral: a brief guide) are particularly important to boosting immune response.

The chart below identifies the role of these vitamins in immunity and shares recommended amounts and sources in the diet. In a forthcoming post, we will highlight the important minerals supporting the immune system and the work Sight and Life has achieved over the past 30 years to ensure access to vital nutrients, especially for children and women of childbearing age.

*Current advice on supplementation concludes that consuming a balanced diet provides all the necessary nutrition required but where there are challenges in meeting dietary recommendations, supplements are a useful addition in helping meet our nutritional needs (EUFIC, 2020).

*Please note these are approximate values and can vary based on recommended reference values employed.

Interested in learning more, read Part II HERE.


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