Researchers from the Nutritional Insight, Surrey, United Kingdom, explored the role of immunonutrition – nutrition that drives immunity for those over 65 years of age.
The researchers call immunonutrition a form of prevention of disease or “prehabilitation”, which could help the “body to cope with potentially lethal viruses such as coronavirus”.
The study titled ‘Covid-19: Is There a Role for Immunonutrition, Particularly in the Over 65s?’ stated that poor nutrition, protein-energy malnutrition, as well as deficiencies are part of “related lifestyle factors”, which can contribute to a sub-optimally functioning immune system.
The researchers wrote in their study: Certain components of the diet, including fruit, vitamin C, antioxidants, vitamins, minerals, and probioticsare termed as immunonutrition that could help boost immunity and have a possible role in resisting respiratory viruses and diseases.
Researchers duo Emma Derbyshire and Joanne Delange from the Nutritional Insight, Surrey, released the findings in the latest issue of BMJ Nutrition, Prevention, and Health .
78% of adults making a more conscious effort to build immunity amid Covid
The researchers further noted that with age, the immune function declines. This is called ‘immunosenescence’. Both innate and acquired immune systems decline with age. The reasons for this decline include inflammation associated with aging, menopause, andropause, and reduction in T cells, among others.
Some of the main findings of the study noted that some vitamins and minerals, including Vitamin C, A, D, B, C, E, B12, and Zinc, should be taken every day to boost immunity.
Researchers mentioned that Vitamin C helps in the development of the epithelial barrier functions of the respiratory system that prevents invasion by pathogens. It can help prevent pneumonia.
Vitamin D is a powerful immunoregulator and plays a protective role in respiratory infections, stated the researchers, adding that zinc is regarded as a ‘gatekeeper’ of immune function.”
Recommendations
The researchers wrote: “The general public and indeed the aging population should be encouraged to follow guidance from Public Health England and continue taking supplements containing 10 μg of vitamin D daily...”.
They recommend foods rich in vitamin C (broccoli (60 mg/100 g), blackcurrants (130 mg/100 g), fortified breakfast cereals (up to 134 mg/100 g) and oranges (37–52 mg/100 g). They also asked people to take foods rich in natural zinc such as “canned crab (5.7 mg/100 g), canned shrimps (3.7 mg/100 g), canned adzuki beans (≈2.3 mg/100 g) and boiled eggs (1.3 mg/100 g).
The recommendations are for vitamin D supplementation with an upper limit of 50 µg/day and an upper limit of daily zinc at 25 mg/day.
The researchers believe that public health strategies should also focus on immunonutrition as a form of prehabilitation to prevent the spread of the infection, boost recoveries, and reduce the burden on the healthcare systems due to an increase in hospital admissions.