Indian food habit & food ingredients may have a role in lowering the severity & high death rate from COVID-19 in Indians: findings from the first nutrigenomic analysis

Abstract

Background & objectives: During the COVID-19 pandemic, the death rate was reportedly 5-8 fold lower in India which is densely populated as compared to less populated western countries. The aim of this study was to investigate whether dietary habits were associated with the variations in COVID-19 severity and deaths between western and Indian population at the nutrigenomics level.

Methods: In this study nutrigenomics approach was applied. Blood transcriptome of severe COVID-19 patients from three western countries (showing high fatality) and two datasets from Indian patients were used. Gene set enrichment analyses were performed for pathways, metabolites, nutrients, etc., and compared for western and Indian samples to identify the food- and nutrient-related factors, which may be associated with COVID-19 severity. Data on the daily consumption of twelve key food components across four countries were collected and a correlation between nutrigenomics analyses and per capita daily dietary intake was investigated.

Results: Distinct dietary habits of Indians were observed, which may be associated with low death rate from COVID-19. Increased consumption of red meat, dairy products and processed foods by western populations may increase the severity and death rate by activating cytokine storm-related pathways, intussusceptive angiogenesis, hypercapnia and enhancing blood glucose levels due to high contents of sphingolipids, palmitic acid and byproducts such as CO₂ and lipopolysaccharide (LPS). Palmitic acid also induces ACE2 expression and increases the infection rate. Coffee and alcohol that are highly consumed in western countries may increase the severity and death rates from COVID-19 by deregulating blood iron, zinc and triglyceride levels. The components of Indian diets maintain high iron and zinc concentrations in blood and rich fibre in their foods may prevent CO₂ and LPS-mediated COVID-19 severity. Regular consumption of tea by Indians maintains high high-density lipoprotein (HDL) and low triglyceride in blood as catechins in tea act as natural atorvastatin. Importantly, regular consumption of turmeric in daily food by Indians maintains strong immunity and curcumin in turmeric may prevent pathways and mechanisms associated with SARS-CoV-2 infection and COVID-19 severity and lowered the death rate.

Interpretation & conclusions: Our results suggest that Indian food components suppress cytokine storm and various other severity related pathways of COVID-19 and may have a role in lowering severity and death rates from COVID-19 in India as compared to western populations. However, large multi-centered case-control studies are required to support our current findings.

Keywords: sphingolipid; tea; turmeric; COVID-19; Caffeine; death rate; diet- iron; palmitic acid; severity; transcriptome; zinc.

Fig. 1

Schematic flow chart of overall methodology or study design.

Fig. 2

Dietary habits in Indian and western populations. Per capita daily consumption of 12 key foods and nutrients (variables) along with the population density and death rates (person/100,000) in India and three western countries (Also shown in Supplementary Table 1).

Fig. 3

Blood nutrigenomics profiles of samples from western and Indian populations. (A) Number of L. rhamnosus, curcumin, and DHA responsive genes increased with increased disease severity in India and the USA and Greece, but not in Spain. (B) The NES-based analysis shows that the curcumin response score is positive and highest in samples from asymptomatic cases in India compared to the severe cases in India. In contrast, the NES is negative for curcumin in all samples in western countries (Black arrow). NES, net enrichment score.

Fig. 4

Key dietary and nutrient interactions with COVID-19 pathways at molecular level that determines COVID-19 severity and fatality rates in Indian and Western populations. The figure is developed based on our results, available literature,-.↑ and ▲ indicate upregulation or increase, ← is activation, and Tdenotes inhibition.