Chemicals including chemical pesticides and solvents in our food have been associated with increased risk of cancers, auto-immune diseases, neurological problems, reproductive and birth defects. However, what is new is the role for chemical toxins in the development of obesity and associated conditions including diabetes, heart disease and high blood pressure.
For the first time, a novel idea published in the Journal of Alternative and Complementary Medicine in 2002, postulated the role of chemical toxins in the development of obesity. This hypothesis led to the review of data showing that the current epidemic of obesity coincides with the marked increase in the industrial use of chemicals in the last 40 years. Numerous studies have stated that chemicals such as pesticides DDE, HCB, organo-phosphates, heavy metals and solvents cause weight gain, possibly by interfering with weight regulating hormones, neurotransmitters and altering the nervous system. These chemicals are also being included in the obesogen category, which refers to molecules that inappropriately regulate fat and lipid metabolism to promote obesity.
The fact that obesity is undoubtedly related to faulty eating, sedentary lifestyle and is a complex interaction between genetic behaviour and environmental factors, is well established. However, the relationship between toxic chemical components in the food chain contributing to the escalation of the obesity epidemic is believed to begin even before birth. It suggests that perinatal and early developmental exposures to environmental chemicals may play a role in the development of obesity later in life. A study published in 2007 in the journal ‘Environmental International’ measured concentrations of widely used pesticides and chemicals in blood samples of 700 pregnant mother–child pairs in Greece. A 10-fold increase in the mothers’ pesticide concentrations was associated with higher risks of generalized and abdominal obesity, higher blood pressure and increased body weight in the children.
The scientific hypothesis that adult health and risk of diseases begins in fetal or early neonatal periods is not unique and new. Increasing number of studies now report that exposure to chemicals during critical periods of development at low doses alters developmental programming resulting in obesity. Increasing evidence also links the widespread exposure to pesticides to the global epidemics of type-2 diabetes and obesity. A 2015 animal study published in the journal ‘Environmental Research’ reported that mice exposed to a commonly used pesticide (organophosphate), showed increase in food ingestion, blood glucose, cholesterol and body fat regulating hormones including ghrelin, leptin and insulin.
Identification of these obesogens, originating from pesticides and chemicals in our food and gene-environmental interaction is an exciting area of future research in the wake of the growing uncapped epidemic of obesity. Meanwhile, a healthy diet, regular physical activity, stress management, along with ‘adopting organic’ is surely a prudent approach to safeguard our well being.
Author is a clinical nutritionist and founder of http://www.theweightmonitor.com and Whole Foods India