St John's Medical College, Bangalore, India
Dunn Clinical Nutrition Center, Cambridge, UK
St John’s Medical College, Bangalore
In my undergraduate days, I was intrigued by Burkitt’s work in Africa, which described the benefits of dietary fiber and the ills of a ‘westernized diet’. That was a remote concern in India at the time, but even so, when Dr Prakash Shetty, who was then in the Department of Physiology at St John's Medical College, invited me to work with him on dietary fiber and colonic physiology, I jumped at the opportunity. My engagement with human metabolism grew outward in subsequent post-doctoral associations with Philip James and Marinos Elia in the UK, where I learnt to use stable isotope probes of metabolic substrates to investigate the role of the sympathetic nervous system in energy metabolism adaptations. As a young faculty member in St John’s, I was fortunate to run into Vernon Young from MIT, who invited me to develop a stable isotopic method to investigate essential amino acid requirements. This was fascinating work that eventually led to a change in the WHO/FAO policy relating to the protein requirements of man. It also showed me how basic human biological work could have profound implications on policy that was not only relevant to human health, but also to food production. That set me on a path to engage with public health and policy.
India was changing in rapid and unsettling ways, and still is. It became evident that the Indian phenotype and environmental exposure were somewhat unique, with a vulnerability to the ill-effects of both under- and overnutrition. Good basic physiological investigations into mechanistic biology were needed to underpin the epidemiological evidence available, and to inform initiatives to supplement nutrition. From the food perspective, science had also largely ignored important research into traditional food groups like pulses, millets and green leafy vegetables, which are important sources of protein, minerals and vitamins; all attributes of a good quality diet. How they are digested and absorbed, particularly in India, with its own peculiar environmental concerns, is also a question.
It is a full circle now, from my beginnings with the ‘westernized diet’. It is no longer a remote concern in India. We still do not know how well food is digested and its nutrients absorbed, even if it were of good quality. After nutrients are absorbed, relatively non-invasive evaluations of their acute and chronic effects on physiological function and health are important. It is complex, because of the confounding effects of environmental enteropathy on absorption, the need to develop non-invasive, sensitive and dynamic strategies that can be used to measure nutrient absorption and their efficacy in vulnerable populations.