Poor health, including poor metabolic health, has been associated with increased risk and severity of COVID-19.
Examples of sub-par metabolic health include high levels of blood sugar, triglycerides, HDL cholesterol, blood pressure, and waist circumference – all of which can be related to diet.
This begs the question: how does diet impact risk and severity of the novel coronavirus?
According to researchers from King’s College London and Harvard Medical School, such evidence is lacking. To address this gap, the researchers analysed data for 592,571 participants in the UK and US from a smartphone-based COVID Symptom Study, with a particular focus on diet quality, risk and severity of COVID-19, and its intersection with socioeconomic deprivation.
Analysing diet and socioeconomics
The COVID Symptom Study included participants recruited between March and December 2020.
Aside from reporting on COVID-19 symptoms and personal medical history, participants were asked to report on diet and lifestyle habits. Their postcodes were also noted.
Specifically, they were asked how often on average they consumed one portion of a particular food item (out of 27 food items in total).
Findings in the preprint paper, that has yet to be peer-reviewed, revealed that those with the healthiest diets, were more likely to be older, female, healthcare workers, of lower BMI, and/or to engage in physical activities five days per week or more. They were also less likely to live in areas with higher socioeconomic deprivation.
Throughout the study, 31,815 cases of COVID-19 were documented, with over 3,886,274 ‘person-months’ of follow-ups. Amongst these, COVID-19 rates per 10,000 person-months were 72 for participants judged to have the healthiest diets, while this increased to 104.1 for those with the poorest diets.
Ultimately, the researchers concluded that high diet quality, compared to low diet quality, was associated with lower COVID-19 risk.
Findings were echoed concerning COVID-19 severity, whereby high diet quality, as compared to low diet quality, was associated with lower risk of severe COVID-19.
Similarly, diet quality was lower and COVID-19 risk higher in areas of ‘high socioeconomic deprivation’ and those reporting low physical activity levels.
Addressing social determinants of health
The researchers’ data, they said, provide evidence that a healthy diet – one characterised by ‘healthy plant foods’ – was associated with both lower risk and severity of the novel coronavirus, even after accounting for other healthy behaviours, social determinants of health, and virus transmission measures.
“The joint association of diet quality and socioeconomic deprivation was greater than the addition of the risks associated with each individual factor, suggesting that diet quality may play a direct influence in COVID-19 susceptibility and progression,” they continued.
“Our findings suggest that public health interventions to improve nutrition and poor metabolic health and address social determinant of health may be important for reducing the burden of the pandemic.”
‘Diet quality and risk and severity of COVID-19: a prospective cohort study’
Published online 25 June 2021
Authors: Jordi Merino, Amid D. Joshi, Long H. Nguyen, et al.