Study finds three unique milk-digestion gene variants in Indian Himalayan communities | Varanasi News

Varanasi: Three genetic variants linked to the ability to digest milk have been identified for the first time in an Indian population, with a major study revealing how centuries of dairy consumption shaped the genetic adaptation of Himalayan communities to high-altitude living. The study, conducted by 13 scientists from five institutions, found that populations such as the Bhutia, Tamang and Sherpa carry distinct genetic mutations associated with lactase persistence.The study was jointly conducted by the Department of Zoology, University of Calcutta; Cytogenetics Laboratory, Department of Zoology, BHU; Laboratory of Genomics and Profiling Applications, Hyderabad; Centre for Genetic Disorders, BHU; and CSIR-Centre for Cellular and Molecular Biology, Hyderabad.Researchers analysed DNA samples from several Himalayan communities to understand how high-altitude populations adapted to harsh climates and distinct dietary practices.BHU geneticist Prof Gyaneshwer Chaubey said researchers plan to conduct broader genome sequencing and clinical studies to better understand the biological mechanisms behind these genetic adaptations.University of Calcutta associate professor Rakesh Tamang said traditional Himalayan communities such as the Bhutia, Tamang, Sherpa and other groups of Tibetan origin have been associated with pastoral and dairy-based lifestyles for centuries. The study found that these groups carry not only the lactase-tolerance variant common in Europe and the Indian plains but also a major variant associated with populations of the Tibetan Plateau.Shaptaparni De, the study’s first author, said prolonged consumption of milk and dairy products helped these communities meet their nutritional needs in extreme Himalayan conditions. Over generations, this dietary practice contributed to adaptive genetic changes, a process known as convergent evolution or gene-culture co-evolution.To support the findings, scientists compared genetic data from major linguistic groups in India, including Indo-European, Dravidian, Austroasiatic and Tibeto-Burman speakers. The analysis showed that Himalayan populations, particularly those of Tibetan origin, have a distinct genetic profile compared with populations in the plains.Chandana Basu, a scientist at the Centre for Genetic Disorders, BHU, said the findings would help explain the origin of milk and lactose tolerance in South Asia, especially India. The study may also offer new insights into ancient migration, historic trade routes and high-altitude biological adaptation.