Industrial Pollutants in Vegans

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What is the impact of adopting a vegan diet on the concentrations of organochlorines in the blood? What are organochlorines? Organochlorines are chemical products that were widely used after World War II as insecticides, and in industry. In the 1960s, their adverse effects for the environment and human health began to be known, and in the 1970s, their use was banned in most industrialized countries, including the United States.

However, because they are so resistant to degradation, many of these persistent organic pollutants continue to be present in most food chains worldwide. Furthermore, because they are attracted to fat, these chemicals accumulate in the fat tissue of organisms. Being at the top of the food chain, humans are contaminated via food, in infancy, from what their moms ate, and later from animal products such as fish, meat and dairy products.

But vegans don’t eat any animal products, which are the main source of these toxic pollutants, so their exposure to these compounds should theoretically be lower than that of non-vegetarians. There are studies showing lower concentrations in the breast milk or fat tissue of vegetarians, but what about vegans?

They found that vegans were significantly less polluted than omnivores regarding a whole list of carcinogenic industrial toxins and pesticides—even after controlling for age and weight, which makes the difference in contamination even more dramatic, because, of course, the vegans had less body fat.

What surprised the researchers was that the vegans had as much as they did. Here’s the data. As you can see, there are certainly lower levels among vegans compared to omnivores. But why isn’t there an even bigger spread?

The researchers offered a number of explanations. The vegans may have been breastfed as infants, and thus exposed to organochlorines accumulated by their mother, which are then transferred to her baby at the time of lactation. And most vegans aren’t vegan from birth. Becoming vegetarian or vegan is often a decision made in adulthood. Thus, the omnivore diet followed during childhood and adolescence results in a contamination by accumulated organochlorine compounds.

And in addition, vegans may, on rare occasions, depart from their diet and eat some animal products, and contaminate themselves that way.

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• H. Arguin; M. Sánchez; G.A. Bray; J.C. Lovejoy; J.C. Peters; R.J. Jandacek; J.P. Chaput & A. Tremblay. Impact of adopting a vegan diet or an olestra supplementation on plasma organochlorine concentrations: results from two pilot studies. Br J Nutr., 103(10):1433-41, 2010.

Image thanks to Daniel Catt via flickr

• adolescence
• animal fat
• animal products
• body fat
• breast milk
• carcinogens
• children
• factory farming practices
• fat
• industrial pollutants
• infants
• omnivores
• persistent organic pollutants
• pesticides
• plant-based diets
• vegans
• vegetarians
• women's health