Jade Teta ND, CSCS
If you are a personal trainer, nutritionist, physician, or fitness enthusiast and you still think being overweight is all about calories in vs. calories out, here is some new research that may finally change your mind. A new study published in the April 13th, 2009 issue of the journal PLoS ONE has shown environmental toxins are a significant factor in obesity (4). This is an issue I deal with in my clinic everyday. Since I work as both a personal trainer and physician I have seen first hand how metabolic fat-burning can be drastically impacted by food quality (i.e., bad fats, white carbohydrates., etc) food toxicity (i.e., gluten sensitivity/allergy) and chemical toxicity (mercury, pesticides, plasticizers, etc). It is a huge oversight among many in the weight loss industry and something that is becoming a much bigger issue than many professionals understand.
Pollutants do make us fat
Persistent organic pollutants (POPS) is the term researchers use to describe chemical toxins found in ground water and soil that have been shown to concentrate in plants and animals, move up the food chain, and can be consumed by humans. Past research by Lee Et. Al. in 2006 (1) has already shown a positive association between elevated blood levels of POPS and severe metabolic dysfunction. One particularly prevalent toxin is the herbicide atrazine. Atrazine is sprayed on crops, especially corn, and is found in high concentrations across the US with the highest concentrations in the Midwest and Southeast. This is also the area of our country with the highest prevalence of obesity. Interestingly, several review studies have been published that show that the introduction and use of atrocine starting in the early 1960′s closely matches the rise of obesity in many areas of our country (2,3). I posted the diagrams in the article showing this trend (the concentrations of atrocine are shown on the top, while the obesity concentrations are shown on the bottom).
It is important not to draw exaggerated conclusions from this data. There are many other factors that have even closer correlation to obesity in our country. However, it is interesting to me that many people blame calories and especially high fat diets as the major reason there is a problem. Research studies do not bare this out. As a matter of fact calorie consumption has not changed much and fat intake has actually decreased during the time obesity has risen in our country. Evidence shows fat intake has actually dropped in the US between 1971 and 2000 while at the same time obesity rates skyrocketed from 14.5% to 30.9% over the same time. However, dietary carbohydrate intake increased significantly along with reductions in activity (5,6). Based on this information toxicity, carbohydrate intake, and decreased physical activity may be more to blame for the obesity epidemic than fat and calories.
How atrazine and other pollutants interrupt metabolism
In this recent study is was shown that atrozine acts as a “hormone disruptor”. Trace amounts of this chemical resulted in negative and persistent alterations in insulin and leptin levels, two hormones that impact fat storage and appetite respectively. Rats fed trace amounts of this chemical developed metabolic derangement and fat loss resistance while rats not exposed showed no effect. For those who like to understand some of the in-depth science, atrozine was shown to interrupt the key energy producing materials in cells (mitochondria). This could lead not only to difficulty burning fat, but also fatigue. This same chemical along with others has been implicated in cancer as well.
Obesity and weight loss are not simply a matter of calories, and it is the dogmatic adherence to this belief by many top professional in all areas of our health care system that is impeding the ability to make meaningful headway against the obesity epidemic. This study should give pause to anyone in the weight loss industry as well as those who are weight loss resistant. The dogmatic adherence to the calorie model may work some of the time, but it is inadequate for a rising majority of obese client
- Lim S, et. al. Chronic exposure to the herbicide, atrazine, causes mitochondrial dysfunction and insulin resistance. PLoS One. 2009;4(4):e5186
- Lee, et. al. A strong dose-response relation between serum concentrations of persistent organic pollutants and diabetes: results from the National Health and Examination Survey 1999–2002. Diabetes Care 2006;29: 1638–44
- Flegal, et. al. Prevalence and Trends in Obesity Among US Adults, 1999–2000. JAMA: The Journal of the American Medical Association 2002;288: 1723–7.
- Kuczmarski, et. al. Increasing prevalence of overweight among US adults. The National Health and Nutrition Examination Surveys, 1960 to 1991. JAMA: The Journal of the American Medical Association 1994;272: 205–11.
- Wang, et. al. Will all Americans become overweight or obese? estimating the progression and cost of
the US obesity epidemic. Obesity. 2008;16:2323-2330. - Wright, et. al. Trends in intake of energy and macronutrients- United States, 1971-2000.
Morbidity and Mortality Weekly report 2004;53:80-82.
