Idli-sambar and rajma rice are among an array of Indian foods that may have saved many in the country from death during the COVID-19 pandemic, a new scientific study said.
The study by a team comprising scientists from Brazil, Jordan, Switzerland, Saudi Arabia, and India was published in the April edition of the Indian Journal of Medical Research by the Indian Council of Medical Research (ICMR).
The infection and death rates in the case of pandemics are likely to be higher in densely populated countries. But India presented the opposite picture during COVID-19 for the researchers.
“If we calculate the death per 1 lakh population, we can see that the death rate in India with 428 people per square kilometre was five-eight times lower than that in less-populated Western countries with a density of 36-92 people per square kilometre,” Debmalya Barh, one of the authors of the study said.
An expert in genomics and precision health who conceptualised and led the research, he is an honorary scientist at the West Bengal-based Institute of Integrative Omics and Applied Biotechnology and teaches at the Federal University of Minas Gerais (UFMG) in Brazil.
“We looked into the phenomena from a precision health point of view where the gene, behaviour, and environment interactions determine the phenotype of any person. As there are huge differences in cultural aspects, including the food habits and food ingredients between India and Western countries, we focused on this area,” he said.
The first to use the nutrigenomics approach for COVID-19 to find an answer, the scientists concluded that food habits and food ingredients probably played an important role, besides vaccination and other measures in reducing the severity and high death rate in Indians.
The researchers first made two groups — low death rate (39 deaths/1,00,000) countries and high death rate (225-300/1,00,000) countries. India was in the former category and the U.S., Greece, and Spain were combined in the latter (Western) category.
Then they identified the per capita daily consumption of key foods, spices, and nutrients between these two groups at the national level of each country. Vegetables, whole grains, legumes, red meat, dairy products, fish, alcohol, coffee, fruit, nuts, tea, and turmeric are found to be the key variables between these two groups.
Finally, they correlated these variables with observed death rates and performed in-depth comparative pathways and nutrigenomics-based analyses of blood transcriptomes of asymptomatic and severe COVID-19 patients from these two groups of populations.
For India, the researchers used transcriptome profiles of COVID-19 patients from south India (Karnataka) and north India (Haryana).
The scientists found that at the national level, Western populations consume 10-20 times more red meat, eight-12 times more processed foods, five-seven times more dairy products, three-eight times more fish, 10-12 times more coffee, and two times more alcohol than Indians. On the other hand, Indians take 1.5 times higher legumes and vegetables, and four times more whole grains than Western populations.
“Most importantly, while the Western populations take no or negligible amount of tea and turmeric, Indians take an average 1.2 gm and 2.5 gm tea and turmeric per person per day, respectively,” Nirmal Kumar Ganguly, the second Indian researcher and former ICMC Director-General said.
File image for representation. | Photo Credit: K. Bhagya Prakash
The researchers highlighted the south Indian idli-sambar and the north Indian rajma-rice. “Indian diets such as idli (rice and black gram 2:1 ratio) sambar (lentil-based vegetable stew), rajma rice, legumes, and whole grain-based vegetarian foods maintain high iron and zinc concentration in blood in Indians,” the study said.
One idli may contain twice the zinc than most commonly used zinc-supplemented vitamin tablets. Additionally, the Indian vegetarian diets are rich in fibre that prevents CO2 and LPS-mediated COVID-19 severity. Catechins present in tea act as natural cholesterol-lowering drug atorvastatin,” the study said.
“We also think that regular consumption of tea by Indians maintains high HDL and low triglyceride in the blood which may have lowered the risk of COVID-19 severity. Most importantly, the Indians consume nearly 2.5 gm of turmeric per person per day through their various foods. The curcumin of turmeric is an immune booster, anti-inflammatory, and antioxidant compound that maintains strong immunity in Indians,” Professor Barh said.
“Our nutrigenomics analyses show Western diets have the properties that can trigger almost all the molecular pathways associated with COVID-19 severity. The increased consumption of red meat, processed foods, and dairy products by Western populations activates cytokine storm and several COVID-19 severity-related pathways,” Professor Ganguly said.
While acknowledging the role of dietary habits in combating COVID-19, the researchers suggested a multi-centred and large-scale case-control study to identify more factors that helped Indians fight the pandemic.
The other authors of the study are Vasco Azevedo and Aristóteles Góes-Neto of UFMG, Alaa A.A. Aljabali of Jordan’s Yarmouk University, Switzerland-based immunology and vaccinology expert Kenneth Lundstrom, and Khalid J. Alzahrani of Saudi Arabia’s Taif University.
Published - April 19, 2023 04:55 pm IST
