Is organic better for us?

Marc CohenA meeting with Professor Marc Cohen is never quick. It’s packed with news of his latest research projects and ideas for more. Conversations digress, leading to related topics, and before you know it you’re convinced the science investigating chemical effects on the body is in good hands – hands that could be more effective if there was more funding.

“It costs $2500 to do just one urine sample test for the chemicals we’re looking for, so it makes it really hard to do individual studies,” Marc says. The professor of Health Science at RMIT University, Melbourne, is a leader in integrative and holistic medicine.

You might be familiar with a study he did with Dr Liza Oates that found one week on an organic diet reduced organophosphates in adults’ urine by 90 per cent. This initial research is being followed up by more studies.

Oooh, it does get in!

The latest study looks at the levels of 480 different pesticides, including organophosphates and glyphosate (the active ingredient in Roundup®), in the urine of adolescents. This will produce the first reports on the levels of these pesticides in Australians and one of the few reports in the world documenting the levels of glyphosate in humans.

Given glyphosate is the most commonly used agrichemical in the world, Marc is surprised that worldwide studies on pesticides and human health haven’t tested for it. “While we don’t know how many different pesticides we’ll find, whatever we find will be news,” he says.

An estimated 8000 pesticides are registered with the Australian Pesticides and Veterinary Medicines Authority (APVMA). Pesticides include herbicides, fungicides and insecticides. Of course this doesn’t mean they’re all used but that’s part of the problem: no one knows exactly how much is used because their sales and application aren’t regulated.

A mothers’ group in the United States found detectable levels of glyphosate in their breast milk and urine. While it wasn’t a scientific study, it suggests the chemical builds up in bodies over time, which is contrary to chemical manufacturers’ advice. Marc would like to see this study repeated and published in scientific literature.

He is also looking forward to getting the results of another study he’s involved in that takes the week-long organic diet study further by testing 480 pesticides in adults (the same 480 tested in the adolescents) before and after a week of eating organic food.

At least it’s in the urine, right?

Some argue that if pesticide residues show up in urine, it means the body is doing a good job of eliminating them. However, while the body may be able to eliminate water soluble pesticides in urine, if people continually consume them, they will maintain an ongoing presence in the body. Marc explains that it is also complex to determine the effects of pesticides because it is not just the type of chemical, it’s also the dose, timing and mixture that makes the poison. It’s also about the accumulation.

“There’s strong evidence that mixture effects may arise when several chemicals are combined at doses of concentrations around, or below, points of departure,” he says. Marc recently summarised the science behind what we know and what we don’t know about our chemical exposure in an article in ABC’s Organic Gardener magazine called ‘The Ten Toxic Truths’, which led to multiple radio interviews on the topic around the country.

Putting athletes to the test

His studies don’t stop at measuring the levels of pesticides but also look at the effects they have on function. He’s planning a rigorous double-blind, randomised, controlled trial of organic food on elite athletic performance. This study will measure the effects of pesticides on athletes at the Australian Institute of Sport. If even a small improvement is seen with an organic diet, this study could revolutionise sports nutrition globally because no elite can afford to give away an edge over their competitors.

“A study like this would be expensive but not prohibitive,” Marc says. He’s looking for a PhD student who might be interested in participating in this, as well as companies willing to provide funding.

Pesticides dumbing down Australia

A recent article published by Dr Philippe Grandjean and Dr Philip Landrigan in The Lancet Neurology, states: “The world is facing a silent pandemic of ‘chemical brain drain’ with increasing rates of neurodevelopmental disabilities, including autism, attention-deficit hyperactivity disorder, dyslexia, and other cognitive impairments.” It declares lead, arsenic, organophosphates, manganese and fluoride as confirmed neurodevelopment toxins and Marc is trying to determine how much of these and other chemicals are in Australian bodies and what effects they’re having.

And then there are the studies he’d like to do on breast milk and cord blood in Australia to compare with similar overseas studies. The organic industry needs more data; however, there are not many Australian researchers prepared to tackle the effects of chemicals. Marc and Liza are investigating issues that can be confronting and worrying, particularly for parents. The good thing is it all leads to greater awareness about the food we eat.

Funding wellness, not illness

The drive of researchers such as Marc and Liza is not enough to get this valuable work done. Australian Organic has contributed towards the costs of their studies but more funding is needed to delve deeper and understand the longer-term effects chemicals have on the body.

Marc would love to hear from companies who are interested in supporting this research. “Funding from just a few companies or a philanthropic organisation would help some of these studies get over the line. It really isn’t a lot of money, but the results could have huge ramifications for our health and for the organic industry.”

If you’re interested in supporting his research, please email Marc on

Further reading:

Environmental Health Perspectives: Estimating Pesticide Exposure from Dietary Intake and Organic Food Choices

Civil Eats: New Science Confirms: If You Eat Organic You’ll be Exposed to Fewer Pesticides

The Conversation: The real cost of pesticides in Australia’s food boom

RMIT University: Going organic for one week cuts pesticide exposure

Friends of the Earth: The Dose Makes the Poison?

Time: Why organic is the right choice for parents

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