Research duo Emma Derbyshire and Joanne Delange from Nutritional Insight, Surrey, UK, are investigating the role of immune nutrition – a diet that boosts or affects the immune system in people over 65 in COVID-19. Your study, entitled “COVID-19: Is There a Role for Immune Nutrition, Especially in Those Over 65?” Was published in the latest edition of the BMJ Nutrition, Prevention and Health.
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected over 60 million people worldwide since it emerged in late December 2019 in the city of Wuhan, Hubei Province, China, with over 1.43 million suffering from severe COVID. 19 disease. The World Health Organization (WHO) declared a pandemic on March 11 this year. Since then, the pandemic has remained one of the greatest public health problems in recent human memory.
Public health strategies to prevent the spread of this highly infectious virus include social distancing, preventing gatherings, wearing masks, and hand hygiene. The focus was not on the immune system and foods that might boost the immune system, the researchers write.
This review sought to collect the available evidence of immune nutrition, or a diet and diet that helps strengthen the immune system, particularly in the elderly, who are more prone to SARS-CoV-2 infection and its complications.
The researchers refer to immune nutrition as a form of disease prevention or “prehabilitation” that could “help the body deal with potentially deadly viruses like the coronavirus”.
The researchers explain that the definition of prehabilitation in the scientific literature states that they are “interventions that can help improve the patient’s health when exposed to a physiological stressor, so that they can better manage that stress . “
Diet and Illness
The researchers say there is abundant evidence that poor diet, protein-energy malnutrition, and deficiencies in micronutrients such as vitamins and minerals are part of “related lifestyle factors” that can contribute to a sub-optimally functioning immune system.
Certain components of the diet, including fruits, vitamin C, antioxidants, vitamins, minerals and probiotics, are called immune nutrition, which help boost immunity and may play a role in “resistance to respiratory viruses and diseases,” the researchers write .
SARS CoV-2 and the immune system
The raging COVID-19 pandemic around the world is caused by SARS-CoV-2, which is part of the coronavirus family. There are currently no safe and effective treatments for this virus, nor are there any vaccines to prevent infection. SARS-CoV-2 can cause atypical viral pneumonia in some vulnerable people, especially the elderly. Some may even need oxygen or artificial respiration and intensive care. Elderly people with other health problems like heart disease, obesity, diabetes, etc. may be at higher risk of developing complications like acute respiratory distress syndrome (ARDS), which leads to multiple organ failure and even death.
The immune system is made up of four components – T cells, B cells, the complement system, and phagocytes. There are two arms of the immune system – innate and adaptive immunity. These protect the body from infections. A healthy diet strengthens the immune system.
The team writes that Professor Philip Calder, an expert on immune nutrition, says in his article “Feeding the Immune System” that the immune system acts as a barrier against incoming infections.
Age and Immune System
Immune function decreases with age. This is known as “immunosensitivity”. Both the innate and acquired immune systems decrease with age. The reasons for this decline are:
- Decrease in T cell functions due to thymus involution and decrease in the production of new naive T cells
- “Inflammation” or inflammation related to aging
- Bad nutritional status related to age. Micronutrient deficiencies typically occur in older people
- Menopause and andropause can also contribute to nutrient deficiencies
Immune nutrition and COVID-19
Some of the key findings of the researchers’ scientific literature review were:
- A healthy immune system needs vitamins A, D, C, E, B6, B12, folic acid, copper, iron, zinc and selenium. There is an interplay of these nutrients in a healthy immune system
- Immune nutrients of considerable importance are vitamins C, D and zinc.
- Vitamin C helps develop the epithelial barrier functions of the airways, which prevent the invasion of pathogens. It can help prevent pneumonia.
- Vitamin D is a powerful immune regulator. B and T lymphocytes, macrophages, and monocytes are some of the immune cells that have vitamin D receptors on their surface. Vitamin D plays a protective role in respiratory infections
- The authors write: “Zinc is considered the” gatekeeper “of immune function.”
The researchers wrote, “The general public, and indeed the aging population, should be encouraged to follow Public Health England instructions and continue to take supplements containing 10 micrograms of vitamin D daily …”. They recommend foods high in vitamin C (broccoli (60 mg / 100 g), black currants (130 mg / 100 g), fortified breakfast cereals (up to 134 mg / 100 g), and oranges (37–52 mg / 100 g They recommend foods that are rich in natural zinc, such as canned crabs (5.7 mg / 100 g), canned shrimp (3.7 mg / 100 g), canned adzuki beans (2.3 mg / 100 g). 100 g) and boiled eggs (1.3 mg / 100 g)) ”. The recommendations refer to vitamin D supplementation with an upper limit of 50 µg / day and an upper limit for daily zinc of 25 mg / day.
There is a lack of studies examining the effects of immune nutrients on “vulnerable groups such as those over 65 years of age with underlying health conditions such as asthma, chronic obstructive pulmonary disease, diabetes and heart disease, or those with immunosuppression”.
The research duo believe that public health strategies should also focus on immune nutrition as a form of pre-habilitation to prevent the spread of infection, promote recovery, and reduce the burden on health systems from increased hospital admissions.
- Derbyshire E, Delange JCOVID-19: Is there a role for immune nutrition, especially in those over 65? BMJ Nutrition, Prevention & Health 2020; 3, doi: 10.1136 / bmjnph-2020-000071, https://nutrition.bmj.com/content/3/1/100