Diet and Immune Function

Abstract

A well-functioning immune system is critical for survival. The immune system must be constantly alert, monitoring for signs of invasion or danger. Cells of the immune system must be able to distinguish self from non-self and furthermore discriminate between non-self molecules which are harmful (e.g., those from pathogens) and innocuous non-self molecules (e.g., from food). This Special Issue of Nutrients explores the relationship between diet and nutrients and immune function. In this preface, we outline the key functions of the immune system, and how it interacts with nutrients across the life course, highlighting the work included within this Special Issue. This includes the role of macronutrients, micronutrients, and the gut microbiome in mediating immunological effects. Nutritional modulation of the immune system has applications within the clinical setting, but can also have a role in healthy populations, acting to reduce or delay the onset of immune-mediated chronic diseases. Ongoing research in this field will ultimately lead to a better understanding of the role of diet and nutrients in immune function and will facilitate the use of bespoke nutrition to improve human health.

Eating habits and lifestyle Changes during COVID-19 lockdown: an Italian survey

“…It was expected that during the quarantine there would be a reduction of the consumption of fresh food, accompanied by vitamins and minerals de ciency, including vitamin C and vitamin E and beta-carotene with antioxidants and anti-in ammatory properties. The de ciency of these micronutrients is associated both obesity and impaired immune responses, thus making more susceptible to viral infections [31,32]. However, during the lockdown, the Italians have paid attention to Mediterranean food, and nutritional quality has remained high, especially in Northern and Central Italy, areas in which there is also a lower BMI than in areas of Southern Italy and the Islands (p<0.05) [33].…”

COVID-19: is there a role for immunonutrition, particularly in the over 65s?

“…3 It is known that viral clearance and infection recovery require activation of the host's immune response, and nutrition could be a means of achieving this. 4 Suboptimal immune competence commonly occurs in later life, with undernutrition, protein-energy malnutrition and micronutrient deficiencies being age-related lifestyle factors that can further hamper this. 5 Undoubtedly there are many nutritional myths of bolstering the immune system, including diet, fruit, vitamin C, antioxidants, vitamins, minerals and probiotics-all typically being mentioned most often on the infosphere.…”

“…5 It has been elegantly stated that an ideal immune system should be 'constantly alert and monitoring for signs of danger or invasion'. 4 Professor Philip Calder is one of the leading experts in nutritional immunology and has published widely on this topic. In his article 'Feeding the Immune System', he explains that the immune system functions by acting as an exclusion barrier, identifying and eliminating pathogens and involving complex interplay between many different cell types and chemical mediators.…”

Healthy Lifestyle Behaviors Are Major Predictors of Mental Wellbeing During COVID-19 Pandemic Confinement: A Study on Adult Arabs in Higher Educational Institutions

“…Thus, a proper nutrition become of vital importance to support immune system and improve energy balance, in order to reduce the risk of developing chronic and infectious diseases. [16] Staying stuck at home, especially if it has low levels of natural light, may reduce light-based signals for wakefulness and sleep, which are necessary for our daily rhythm (circadian). Especially since many do not work or have their weekly working hours reduced due to COVID-19, the majority of them may be tempted to sleep every morning.…”