The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the coronavirus disease 2019 (COVID-19) pandemic, has had a significant impact on the global healthcare industry and economy. In addition, the prevalence of long-term COVID, characterised by the persistence of symptoms for more than three months, has had a significant impact on millions of people.
Several COVID-19 vaccines, therapeutics, and non-pharmaceutical interventions have been developed to combat the ongoing pandemic. However, a better understanding of the risk factors associated with SARS-CoV-2 infection would aid in preventing future infections.
Nutrition is the most important source of energy and a major determinant of human health. A balanced diet is associated with the maintenance of a healthy gut microbiome, which is a crucial factor in immune regulation.
According to a recent study, those who consume more fruits and vegetables and a healthy plant-based diet have a lower risk of contracting COVID-19. This observation suggests a possible association between diet and COVID-19.
The NOVA classification system categorises food-based products into four groups based on the extent and function of their industrial processing. Ultra-processed foods (UPFs) are industrial formulations of processed food ingredients such as fats, oils, starch, sugar, and protein isolates. By adding colorings, flavourings, and emulsifiers, these food products undergo hydrogenation, hydrolysis, or other chemical processing.
In general, UPFs are rich in saturated fats, sugars, trans fats, and sodium. In addition, these products contain low quantities of protein, fibre, vitamins, and minerals.
Several studies suggest that UPFs are the primary dietary source of food adulterants and neo-formed compounds, which may alter the gut microbiome and increase the risk of inflammation.
About the research
Individuals who rely heavily on a UPF-rich diet frequently suffer from mineral and vitamin deficiencies, immune system damage, and heightened susceptibility to infections. The presence of UPFs is associated with an increased risk of inflammatory bowel disease, cardiovascular disease, and cancer.
Scientists have observed a dearth of evidence regarding the association between UPF consumption and COVID-19 risk. A recent study published in the European Journal of Nutrition investigated the relationship between UPF consumption and the risk of SARS-CoV-2 infection.
The current study utilised data from the United Kingdom Biobank, a prospective cohort consisting of approximately 500,000 participants from 22 assessment centres in Scotland, Wales, and England. All study participants were between the ages of 40 and 69. In this study, 41,012 participants from the U.K. Biobank were considered.
Utilizing the Oxford WebQ dietary questionnaire, scientists assessed the participants’ dietary intake over the previous 24 hours. This questionnaire included 206 food items and their quantities, as well as 32 beverages.
The online dietary questionnaire was recalled a minimum of twice and a maximum of five times for the 24-hour dietary assessment. Using an adjusted multivariable logistic regression, the current study measured the association between UPF consumption, as indicated by the percent daily gramme intake, and SARS-CoV-2 infection.
A significant correlation between UPF consumption and increased COVID-19 risk was observed. This association was consistent across age, comorbidity status, and educational level subgroups.
Despite the fact that the association between UPF consumption and COVID-19 was partially mediated by body mass index (BMI), a direct effect of UPF weight ratio on COVID-19 risk was established.
Among the mechanisms connecting UPF consumption and an increased risk of COVID-19 are elevated sugar and trans-fat levels, which stimulate pro-inflammatory effects. This condition may impair the production and function of immune cells.
Moreover, UPFs are rich in saturated fats and low in fibre, which may result in chronic activation of the innate immune system and suppression of the adaptive immune system. Chemical additives to UPFs are also detrimental to human health. In addition, a diet high in UPF may result in vitamin and mineral deficiencies, which could have a significant impact on the human immune system.
It was discovered that BMI partially mediated the association between UPF and COVID-19. During the COVID-19 lockdown, there was a significant increase in UPF consumption, which may have affected people’s immunity and made them more susceptible to infection.
This is the first study to investigate the association between UPF consumption and the risk of SARS-CoV-2 infection. This large prospective cohort study found that a diet high in UPF was associated with a substantially increased risk of COVID-19. To protect against severe clinical outcomes, a healthy diet with reduced UPF consumption has been recommended.
- Zhou, L., Li, H., Zhang, S. et al. (2022) Impact of ultra-processed food intake on the risk of COVID-19: a prospective cohort study. European Journal of Nutrition. doi:10.1007/s00394-022-02982-0