Tuesday, August 19, 2014

Obesogens - More than a Calorie

Maybe NOT!

Have you ever heard that obesity results from too many calories in vs. the number of calories out? The simple solution for being overweight is then to balance the energy equation by eating less and exercising more... right? Well, maybe this is not the case for everyone; what if a calorie in, is more than a calorie out? Perhaps there is an assortment of factors which provide more pathways which result in a growing number of individuals to retain more calories than they expend. 

Our guest writer Joe Kugler will present below some recent evidence that many chemicals present in our everyday life could be responsible for a significant rise in obesity. Additionally, that the institute for health metrics at the University of Washingtion reported in May 2014 that 29% of the world's population (2.1billion people) were either overweight or obese. What's alarming about that statistic is that the obese segment of the population in adults has increased by 27.5% since 1980. And interestingly, the team at the Health Institute in Washington observed substantial increases in BMI and abdominal obesity over the years, however they did not find any significant increases in caloric consumption.... "say what?" 

So, besides a world wide reduction in exercise and physical activity since 1980, Joe Kugler, a student of Kinesiology in Vancouver BC, explores another theory to challenge the typical energy budget as depicted in the diagram above. 

Con't from pg 7 of his atricle Kugler explains:  

In 2006, Dr. Bruce Blumberg, who was studying a class of compounds call Organotins, coined the term Obesogens for a group of chemicals  that seem to promote obesity by increasing the number of fat cells (and fat storage into existing fat cells), changing the amount of calories burned at rest, altering energy balance to favor storage of calories, and altering the mechanisms through which the body regulates appetite and satiety (Janesick 2012). Although the majority of studies on Obesogens have been animal studies, it seems likely that these chemicals will be found to have similar effects on humans ­- especially on prenatal fetuses, infants, children, and adolescents (Holtcamp 2012). Some Obesogens have been hypothesized to even directly affect adults, with epidemiologic studies linking levels of chemicals in human blood with obesity (Tang 2011) and studies showing that certain pharmaceuticals activate PPARĪ³ receptors (Lustig 2010) causing weight gain in patients taking them.

Obesogens are pervasive in our environment and humans are not the only organisms being exposed. Our pets and animals that share our immediate ecosystem are exposed to many of these Obesogens as well. While diet and lack of exercise continue to be seen as the root cause of the energy balance equation breaking down and of the resultant human obesity epidemic; this cannot explain the results of a recent study, which showed that eight species of animals, including pets, laboratory animals, and feral rats living in proximity to humans, have become obese in parallel with the human obesity epidemic (Klimentidis et al. 2011). The likelihood of this being a chance occurrence has been estimated at about 1 in 10 million (Klimentidis et al. 2011).

Dr. Blumberg discovered that undifferentiated stem cells exposed to a particular Organotin called tributyltin or TBT showed a preference to become fat cells instead of bone or cartilage cells. And when exposed to low doses of TBT, the animals he was studying became fatter.

*** What this means is that mirco doses of obesogens in our diets and activities of daily living are causing a cascade of chemical reactions in our bodies and can potentially make us retain more fat than we consume. ***

So where are Obesogens?

Organotins, including TBT, have many applications including use as stabilisers in PVC, catalysts in chemical reactions, glass coatings, agricultural pesticides, biocides in marine antifoulant paints and wood treatments and preservatives (Batt, 2006) and in anti­odour/anti­fungal treatments for textiles and textile polymers (Greenpeace, 2003b, Peters, 2006). Because of this wide spread use, TBT eventually ends up in our everyday lives. It has been found in soil, household dust, and carpets (Kannan 2010). It is present in contaminated seafood and it has a half life of 87 ∓ 17 years in deep sediments found in shipping ports and harbours (Cardwell 1999). Although now banned, TBT continues to be found in marine environments and most likely will continue to be present for decades. (Cardwell 1999). It has been found in samples of human blood, liver and milk samples. (Kannan 1999) (Mino 2008)(Nielsen 2002).

Since the initial discovery that TBT exposure had an impact on weight, approximately 15­-20 other chemicals have been found to have the same effects including bisphenol A (Summ 2009), perfluorooctanoic acid (PFOA) (Hines 2009) , and even fructose has been implicated (Goran 2013). These three chemicals are pervasive in modern society. Bisphenol A is found in many plastic products especially those with recycle code 7 and it was banned from baby bottles and sippy cups in 2012, however it continues to be allowed in other drinking containers. PFOA is a surfactant used for reduction of friction, and it is also used in nonstick cookware, Gore­Tex™ waterproof clothing, Scotchgard™ stain repellent on carpeting, mattresses, and microwavable food items (Holtcamp 2012). Fructose is omnipresent in the food supply as High Fructose Corn Syrup. 

The continued reliance on “eat less, exercise more” as the only response to the global obesity epidemic seems to be more than a bit naive given the growing body of evidence pointing to the role of Obesogens as endocrine disruptors interfering with the bodies processing of calories, feelings of fullness, and the basic functioning of stem cell differentiation. Certainly, the ease of access to calorie dense foods and lack of physical activity are important to the development of the obesity epidemic, but more seems to be going on. Even people in the lower end of the BMI curve, for whom the energy balance equation should be working, are getting heavier in tandem with those in the overweight and obese portions of the curve (Lustig 2006). So, whatever is happening appears to be affecting everyone not just those who are overweight or obese.

Although the obesity epidemic may be being helped along by the obesogens, government and society at large must do more to promote physical activity and ensure that healthy food choices are affordable and readily available to all segments of the population. And in return, individuals must avail themselves of these resources. In the meantime, take Dr Blumberg’s advice and limit your exposure to these obesogens by eating organic foods, eliminate or at least reduce the use of plastic to store and serve food and beverages, and avoid processed foods (Blumberg 2012).

-  Thanks Joe Kugler BSc.

Cameron Hunt Regsitered Kinesiologist

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