Dr Dwaipayan Bharadwaj talks about the role an individual’s environment plays in the case of Type 2 Diabetes in a chat with Deepti Sharma,reported by Sunila Kelkar.
Dr. Dwaipayan Bharadwaj is the Senior Principal Scientist at the Genome and Molecular Medicine Unit with the CSIR – Institute of Genome and Integrative Biology, New Delhi. His research interest is in the field of the genetic basis of Type 2 Diabetes and obesity. He is a part of a group of Indian scientists who have mapped the genetic variations seen among the India’s diverse population. This has paved the way for further research to test the susceptibility to diseases and efficacy of drugs for complex diseases like diabetes, cardiovascular and neuropsychiatric disorders in the Indian population. Dr. Bharadwaj is one of the most eminent scientists in the field of Diabetology in India, and he shares his exciting work with the DH team
Nature versus nurture
Do diseases occur because we are born with certain genes? Or does the environment contribute? The influence of nature as opposed to nurture in an individual’s development is often a topic of lively debate. In recent times questions have been raised whether many environmental factors like age, diet, lifestyle, maternal nutrition, low birth weight, etc. have a strong effect on the manifestation of Type 2 Diabetes. But this correlation is still unclear. This has increased the level of interest towards further research in Epigenetics, a term used to describe how genes themselves are modified by environmental factors.
Epi-(above)–genetics factors are thought to play a role in complex diseases like Diabetes. There are many instances where researchers are unable to pinpoint factors that fully explain how complex traits are passed down from one generation to the next. This suggests the possibility that factors which are beyond genetics such as environmental factor lead to complex diseases. Interest in this field of studying an individual’s environmental stressors has contributed to the study of epigenetics. There have been studies conducted to compare the environmental factors of people with Diabetes to those of people who don’t have Diabetes. The findings denote differences in the genes of these two groups mainly in those genes involved in important metabolic processes. Like any complex disease, Type 2 Diabetes is manifested because of a complex interaction between environmental factors and your genes. Along with a genetic predisposition, environmental factors such as factors like age, diet and lifestyle play a crucial role in the development of Diabetes. Poor eating habits in addition to a sedentary lifestyle may result in the development of Type 2 Diabetes. New research suggests that these environmental factors could actually influence your genes! In other words, genetics, family or heredity-related aspects may in turn be modified by your lifestyle.
Beta cells go on strike
Insulin is essential to control your body’s sugar levels. A diet consisting of a higher intake of sugar and sweets will result in increased production of insulin to deal with the higher blood sugar levels. Consider your pancreas to be a factory and the beta cells to be the factory workers. To tackle this higher blood sugar level, the beta cells in the pancreas will have to secrete more and more insulin to maintain the sugar level. This results in the factory being overworked and the factory workers so fatigued that they very soon start secreting bad quality insulin or no insulin at all. This results in hyperglycemias (high blood sugar level). Continued hyperglycaemia is associated with hypertension, obesity which in turn leads to severe vascular complications such as an increased risk of cardiovascular disorders. These health concerns may be avoided by people who exercise regularly and consume a balanced diet resulting in normal levels of insulin secretion.
Blame your brain
There have been newer research findings which hint at a novel neural connection to Diabetes. Disease related genes and pathways have been identified that affect the onset of Type 2 Diabetes. A massive sample of over 12,500 people from the Indian sub-continent was collected. This helped identify a neuro- gene with no previous association to Diabetes. This was the most commonly recognised gene in the majority of the Indian population who were tested. This gene was found to increase the risk of developing Type 2 Diabetes in the Indian population to 1.6 times higher. This established the existence of a neurological link that influenced the manifestation of Diabetes. This has led to the line of thought that Diabetes could be a form of a neurological disorder – it probably clarifies why we give in to the temptation to eat aesthetically appealing food.
Environmental determinants influencing childhood obesity
The socio-economic divide plays a unique role with regards to the manifestation of Type 2 Diabetes in India. As is seen in adults, children from affluent backgrounds who lead a sedentary lifestyle are more vulnerable to Diabetes than those from a weaker economical background. The advent of technology has altered the manner in which children entertain themselves. Playing outdoor games has been replaced with computer games. This paradigm shift in lifestyle leads to burning of fewer calories. Additionally, intake of food which has more calories but very low nutritive value has also resulted in an increased risk of onset of Diabetes.
To conclude, good glycemic control, hypertension and lipid management along with annual Diabetic Retinopathy screening by fundus examination is essential for preventing blindness and visual impairment caused due to Diabetic Retinopathy.
On the other hand, underprivileged children rarely lead a sedentary lifestyle. Not only do these children have a lower access to high calorie foods like pizzas, burgers and cola drinks but their financial constraints also restricts their intake of these foods. In India, this has resulted a higher number of affluent children being obese than the underprivileged children. But a reverse trend is seen in the United States of America where obesity is more prevalent in the underprivileged sections of society. There the high calorie foods such as pizzas, burgers and cola drinks are more inexpensive than healthy foods. This reiterates that faulty food intake is a leading cause of obesity which in turn could lead to Diabetes.
Your choices matter
Around 60 known genes cause Diabetes, a complex disease. But this only explains the causation of about only about 10 per cent of the risk of diabetes further bolstering the role played by environmental and lifestyle risk factors. This brings forth the fact that in spite of a genetic predisposition for Diabetes, any individual can initiate and implement preventive and corrective measures. This is done simply by appropriate management of your lifestyle choices.