Nutrient supplementation has very little or no effect on prevention of viral respiratory tract infections in healthy individuals
KRAKOW, Poland, July 11, 2021 /PRNewswire/ — A Taskforce on Nutrition and Immunomodulation of the European Academy of Allergy and Clinical Immunology (EAACI) examined the question of whether the use of nutrient supplements by healthy children and adults in different world regions can prevent viral respiratory tract infections (RTIs), such as COVID-19.
The task force concluded that nutrient supplementation has very little or no effect on prevention of RTIs in healthy individuals. Zinc supplementation appears to offer some protection for children only in Asia. Vitamin D may have some protection in adults, but only in the USA and Canada.
The results will be presented at the yearly conference of the EAACI Hybrid Congress 2021 in Krakow, Poland by Dr. Berber Vlieg-Boerstra, research dietitian at OLVG Hospital, Amsterdam, the Netherlands.
Over a period of one year, the taskforce conducted a comprehensive systematic review on the topic to identify and better understand modifiable factors, such as nutrient supplementation, that could enhance the immune response to improve resistance to RTIs, such as COVID-19, in the general population.
The taskforce assessed the scientific evidence from 115 studies until April 2020, encompassing 199,055 subjects (191,636 children and 7,419 adults) from 37 countries, for nutrients which have a recognized role in immune function. These were multiple micronutrients, vitamin A, folic acid, vitamins B12, C, D and E, beta-carotene, zinc, iron and long chain polyunsaturated fatty acids.
All available scientific literature on the research question was studied and only randomized controlled trials in humans, studies with the highest level of evidence, were included. In these studies, the effect of supplement administration in healthy children or adults was measured on primary prevention of RTIs as compared to placebo. The taskforce developed a systematic review and meta-analysis, meaning that clearly defined, systematic methods were used and results from several similar studies were combined. Per nutrient, age group (children and adults) and world region results from similar studies were analyzed.
By separately analyzing different world regions, only studies performed in Asia showed any meaningful protective effect of zinc supplementation on RTIs (RR 0.86, 95%CI 0.7-0.96). Vitamin D supplementation in adults showed a slight decrease in the incidence of RTI (RR 0.89, 95%CI 0.79-0.99), particularly in North America (RR 0.82 95%CI 0.68-0.97), but not in Europe or Oceania.
“The main message for the general healthy consumer is that enhancement of the immune function to prevent RTIs, such as COVID-19, is unlikely to be obtained through micronutrient supplementation. In contrast, based on data from the current pandemic, we expect a more promising preventive effect from a healthy, anti-inflammatory lifestyle such as a healthy diet, to enhance our immune system,” say Dr. Berber Vlieg-Boerstra, Dr. Nicolette de Jong (Erasmus MC Rotterdam, the Netherlands and Dr. Bright Nwaru, University of Gothenburg, Sweden) who led the study.
Dr. Berber Vlieg-Boerstra, [email protected]; +31620965612
The European Academy of Allergy and Clinical Immunology (EAACI) is an association of clinicians, researchers and allied health professionals founded in 1956. EAACI is dedicated to improving the health of people affected by allergic diseases. With more 13 000 members from 125 countries and over 75 National Allergy Societies, EAACI is the primary source of expertise in Europe and worldwide for all aspects of allergy.