Narrative Review: Sugar and Rice and the Diabetes Epidemic in India-A Historical Context.

South Asians appear to be particularly susceptible to diabetes. India hosts 18 percent of the world's population but more than 25 percent of the world's diabetics, and individuals of South Asian descent carry this presumed increased risk for diabetes when they emigrate to other parts of the world. One conundrum is that the epidemic of diabetes began around Calcutta (modern day Kolkata) in east India well before it appeared in the United States and Europe, and this emergence occurred despite the frequent occurrence of famines and starvation in India. Here we review the history of diabetes in India and the possible significance of high carbohydrate in low-protein diet contexts. We suggest that the circumstantial relationship between diet and a spectrum that includes diabetes associated with obesity at one end, and impaired glucose tolerance and protein malnutrition (kwashiorkor) at the other, could be significant. If the cause of type 2 diabetes in South Asians is primarily nutritional, and, as suggested by others, aggravated by starvation and famine that increased the risk for low birth weight as an additional risk factor for diabetes, these insights may together help explain an enhanced susceptibility of South Asians to diabetes.