Weed killer, toxic food and your mitochondria

Posted on Mon, 26 May 14

Environmental toxins, especially herbicides, can zap your energy by killing your mitochondria in the same way they kill weeds. Learn how, and what you can do about this little talked about but important environmental health issue.

One of the ways by which herbicides kill weeds is by acting on the membrane of chloroplasts, the components of plant cells involved in photosynthesis. Chloroplasts have a functional structure alike that of our mitochondria, and similarly make energy (although from sunlight, instead of food) and store it in the form of adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide phosphate (NADH).

Considering this remarkable similarity between chloroplasts in the cells of plants and the mitochondria within the cells of animals like us, it should perhaps be no surprise to learn that the herbicides that contaminate our environment and food supply can negatively affect mitochondrial function.

Energy killers

One of the best examples of a herbicide and mitochondrial toxin in our food supply that may have important health effects is atrazine, one of the most commonly used herbicides on food crops. Atrazine inhibits photosynthesis by disrupting electron transport on chloroplast membranes (1). So would the effects of atrazine jump from plants to animals and also inhibit energy production in mitochondria? Well, in a landmark study a research group was able to demonstrate that chronic exposure to low concentrations of atrazine does indeed have a similar toxic effect in animals and impairs mitochondrial function (2).

This discovery was fueled by the hypothesis that atrazine could be playing and important role in the diabetes and obesity epidemic by disrupting energy metabolism and glucose regulation. Indeed the research group that pioneered this work found that atrazine use correlated strikingly with obesity prevalence in humans on geographical maps, especially in farming areas of North America where the herbicide is extensively used. Hypothesizing that atrazine may be disrupting mitochondrial energy production in the same way it disrupts energy production in chloroplasts, they set up their experiment.

The study involved low-dose administration of atrazine in drinking water to rats over a period of 5-months to mimic low-dose human exposure. The effects of atrazine were remarkable; atrazine exposure changed the ultrastructure of mitochondria (they were swollen and malformed), reduced energy synthesis, decreased basal metabolic rate (BMR), and increased body weight as well as intra-abdominal fat and insulin resistance without any change in food intake or physical activity level.

Negative effects of herbicides and other persistent man-made organic pollutants (POPs) such as plastics and pesticides on metabolism have been under investigation in humans as well, and lend further weight to this finding. Using a low calorie diet to induce weight loss, break down body fat and liberate stored pollutants, a research group has found that increased blood levels of POPs correlates with reduced skeletal muscle oxidative capacity, serum thyroid hormone concentration, and resting metabolic rate (3,4). So it appears the effects of these environmental toxins play out in the real world as well.

Roundup controversy

The link between adverse effects of herbicides and human health sparks heated and controversial debate. One of the reasons for this is that chemicals like atrazine are thought to be relatively safe to humans, and that much of this safety data has been funded by the companies that make the chemicals. Another chemical, glyphosate, which is one of the active ingredients in the herbicide Roundup, is an excellent example of the questionable safety of widely used herbicides.

Remarkably, because they are assumed to be safe there is very little exposure and long-term safety data on the major herbicides, including atrazine and glyphosate. However, a recently published study examined exposure to glyphosate in humans and revealed some rather interesting, and concerning, insights (5).

As the authors of the new study point out “glyphosate-containing herbicides are applied in large amounts to crops 2 to 3 times per season to remove weeds and dry out grain in a process called ‘desiccation. Once applied, glyphosate accumulates in leaves, grains or fruit. Glyphosate residues cannot be removed by washing and cooking does not break them down. Glyphosate residues can remain stable in foods for a year or more, even if the foods are frozen, dried or processed.” It would make sense then that food would be a major source of exposure, and this is what they set out to analyze.

This new analysis of glyphosate exposure is particular interesting because the researchers looked at exposure in people consuming organic vs. conventional diets, and also aimed to see if higher glyphosate levels were associated with poorer health. Indeed they found that a conventional diet was associated with significantly higher glyphosate levels, and that people who were chronically ill had significantly higher glyphosate residues when compared to a group of healthy controls.

Although the primary mechanism of action of glyphosate is thought to be inhibition of protein synthesis in plants, and thus considered generally non-toxic to humans, glyphosate-containing herbicides have been shown to impair mitochondrial function, suggesting they may indeed be in important mitochondrial toxins (6). And the assumed safety of glyphosate and similar chemicals has been called into question (7).

Coming clean

There is evidence to suggest that environmental, man-made toxins can have important and very serious health effects (8). And for some people toxic exposure may result in an energy crisis, manifesting as serious debilitating chronic fatigue syndromes (9). At present, the best hope for minimizing the potential effects of herbicides is (a) through toxin avoidance, and (b) through enhancement of detoxification.

As the recent study on glyphosate suggests, an organic diet can minimize exposure (5). In fact, transitioning to an organic diet has been shown to reduce detectable pesticide levels to almost non-detectable levels within just 5-days (10).

In addition to toxin avoidance, natural compounds in foods can be used as part of a nutritional detoxification plan as they influence herbicide absorption, elimination and may reduce toxicity. Here are a few key recommendations (for a free guide visit ScientificWellness.org/Detox):

Protein powder; 2 heaped tablespoons of a good whey or rice protein added to a smoothie daily – the high quality protein helps to support your livers ability to eliminate toxins.^_

N-acetyl-cysteine; 1500-1800 mg daily - increases glutathione, an important natural antioxidant and detoxifier of herbicides.

Green super foods; 1 teaspoon or 3-5 grams of a green food such as Chlorella and/ or Spirulina daily – they reduce absorption of toxins and help with the elimination of stored chemicals.

But perhaps most important is increased awareness of this issue, fortunately events such as The Detox Summit (TheDetoxSummit.com) are set to lift the lid on the can of Roundup.

This article first featured in CAM Magazine, May 2014. 

References:

1. Soloman KR, Baker DB, Richards RP, Dixon KR, Klaine SJ, et al. (1996) Ecological risk assessment of atrzine in North American surface waters. Environ Toxicol Chem 15: 31–76.
2. Lim, S. et al. 2009. Chronic exposure to the herbicide, atrazine, causes mitochondrial dysfunction and insulin resistance. PLoS One 4: e5186. doi: 10.1371/ journal.pone.0005186.
3. Imbeault P, Tremblay A, Simoneau JA, Joanisse DR. Weight loss-induced rise in  plasma pollutant is associated with reduced skeletal muscle oxidative capacity. Am J Physiol Endocrinol Metab. 2002 Mar;282(3):E574-9.
4. Pelletier C, Doucet E, Imbeault P, Tremblay A. Associations between weight loss-induced changes in plasma organochlorine concentrations, serum T(3) concentration, and resting metabolic rate. Toxicol Sci. 2002 May;67(1):46-51.
5. Kruger M, et al. Detection of Glyphosate Residues in Animals and Humans. J Environ Anal Toxicol 2014, 4:2
6. Peixoto F. Comparative effects of the Roundup and glyphosate on mitochondrial  oxidative phosphorylation. Chemosphere. 2005 Dec;61(8):1115-22.
7. Mesnage R, Defarge N, Spiroux de Vendômois J, Séralini GE. Major pesticides are more toxic to human cells than their declared active principles. Biomed Res Int. 2014;2014:179691.
8. Wong MH, Armour MA, Naidu R, Man M. Persistent toxic substances: sources, fates and effects. Rev Environ Health. 2012;27(4):207-13
9. Brown BI. Chronic fatigue syndrome: a personalized integrative medicine approach. Altern Ther Health Med. 2014 Jan-Feb;20(1):29-40
10. Lu C, Barr DB, Pearson MA, Waller LA. Dietary intake and its contribution to longitudinal organophosphorus pesticide exposure in urban/suburban children. Environ Health Perspect. 2008 Apr;116(4):537-42.