Approved Research

Uncovering the cause-and-effect relationship between immunonutrients, infectious diseases and diet-related diseases using UK-Biobank and other cohort studies

Lay summary

Unhealthy dietary habits are major drivers of non-communicable chronic diseases (NCDs), such as obesity, diabetes, cardiovascular diseases and cancer. Moreover, there is a cross-talk between the immune system and the development of these diseases. More specifically, the immune system and inflammatory response are both involved in the development and progression of these diseases through the promotion of a systemic chronic inflammation state. For instance, obesity induces low-chronic inflammation that can eventually start damaging healthy cells, tissues and organs, leading to the development of diabetes and cancer. Immunonutrients can modulate the immune system homeostasis and may have potential to modify susceptibility to develop these diseases. Examples of immunonutrients that are critical for the growth and function of immune cells include vitamin C and D, zinc, copper, and selenium, amongst others.

Today it is postulated that there is a link between infectious diseases and diet-related metabolic diseases. However, little is known on the interaction between these two groups of diseases. Deepen this knowledge is currently a public health priority. Indeed, with new infectious diseases such as COVID-19, which are more severe and more fatal in individuals with obesity, cancer or diabetes, the role of co-morbidities in the susceptibility to and severity of infectious disease has become evident. With regard to infectious diseases, immunonutrients may also enhance the host defense and protection from infections, such as those with SARS-Cov-2 (COVID-19 disease).

A better understanding of the relationship between nutrition, immune function and human health will provide new clues for preventing diet-related diseases including cancer, and in turn, will improve the burden of COVID-19 morbidities and mortality. Thus, we propose to explore the impact that immunonutrients have on the immune system, regarding some inflammatory components and metabolites, their association with the risk of severe outcomes from infection with SARS-CoV-2 and their effect on the risk of developing metabolic and diet-related diseases including diabetes, cancer and obesity. We will apply the combination of different epidemiological approaches including those of traditional observational studies, as well as causal inference methods to elucidate these associations. One of these methods is Mendelian Randomization, which makes use of genetic variants to make causal inferences from observational data. The UK Biobank data will be used to assess these associations. Results will be validated using the European Prospective Investigation into Cancer and Nutrition (EPIC) study and other publicly available data.