We have been hearing that diabetes is a lifestyle disease, an epidemic of modernisation etc. Did it really come suddenly? What about our forefathers?
The incidence of diabetes has definitely increased in the 20th and 21st century. But it is not a new disease. Egyptian papyrus mentions a disease where people urinate a lot and lose weight. Charaka- Samhita talks about Madhumeha, a disease with sweet urine which requires severe diet restriction. In fact the word diabetes means “ that drains”, indicating that it drains off body fluids. Mellitus means sweet like honey. There are a lot of literature reference of sweet urine. Galen, the famous Greek physician attributed diabetes to a urological disorder. For a long time, diabetes was assumed to be a renal malady So whats new about Diabetes mellitus? The incidence and pathophysiological shift with time.
There are few theories on the same but as I said theories are theories and proof may not be solid. One famous hypothesis is the thrifty gene hypothesis. According to this theory, diabetes evolved from an evolutionary adjustment of our body to starvation. As the population increased in the 19th and 20th century, starvation was rampant.
People literally lived on small quantities of small qualities of food for months followed by periods of feasting during aplenty. So body evolved through a “Thrifty gene” which enabled storage of excess food whenever possible as fat deposits. These deposits were relatively refractory to the effects of insulin (the sugar utilisation hormone) just to avoid immediate utilisation. The idea was that the body utilised these fat deposits as source of energy during famines.
With time, most likely people with this capacity survived and their progeny flourished which probably led on to the obesity and Diabetes epidemic. The cost of refined low quality carbohydrates fell in the last century and the diet shifted predominantly to refined carbohydrates and low quality fat. These are easily digestible and get deposited as fat which are refractory to the effects of insulin. This is proposed to be the cause behind the diabetic and obesity epidemic.