Should I Eat Only Organic?


A recent study entitled ‘Association of Frequency of Organic Food Consumption With Cancer Risk: Findings from the NutriNet-Sante Prospective Cohort Study’ has caused quite a stir this week in the media discourse. Time to take a closer look.

This was a population-based prospective cohort study, meaning the researchers examined food intake questionnaires from nearly 70,000 French adults. They agreed to proactively report all foods and beverages consumed at each eating occasion during three 24-hour recall periods. In turn, the researchers created an ‘organic food score’ based on consumption frequencies classified as ‘most of the time’, ‘occasionally’ and ‘never.’ After lots of data crunching, the researchers concluded:

A higher frequency of organic food consumption was associated with a reduced risk of cancer. Although the study findings need to be confirmed, promoting organic food consumption in the general population could be a promising preventive strategy against cancer.

Headlines like these quickly followed.

And then the slightly more tame version hit the newstream too. Note we moved from ‘yes’ to ‘may be yes’ thanks to some more cautious journalists at the LA Times. A subtle difference perhaps, but kudos to @latkarenkaplan for dialing back the sensationalism.

Impressive Study Findings

First off, if you look at the media reports on this study, you may notice stats that appear slightly different from one write-up to the next. That’s because the researchers modeled ‘organic food score’ as both a discreet number using quartiles and then as a continuous one. Let’s not get too hung up on that statistical nuance. Here are some of the rather impressive findings when comparing people who consume organic foods at higher frequencies with those who consume at lower frequencies:

  • 25% reduction of overall cancer risk

  • 21% reduction of postmenopausal breast cancer risk

  • 77% reduction of all lymphomas risk

Also keep in mind the researchers controlled for age, sex, occupation, education level, marital status, income, physical activity, smoking status, alcohol intake, family history of cancer, body mass index, height, energy intake, fiber intake, processed meat intake, red meat intake, and for women, a host of potential confounders like postmenopausal status and use of oral contraception. This sounds like they certainly tried to ‘control for’ all those variables that could mess up their findings.

So Eat Only Organic?

While the findings are impressive and deserve serious consideration, there’s one rather glaring flaw in this analysis. Looking past the notion that the French volunteers simply had to jot down organic food intake based on ‘most of the time’ versus ‘never’ type categories (which that is already kinda questionable in terms of reliability), my issue is that the researchers are assuming that organic food intake frequency equates with quantification of pesticide intake.

It’s tempting to assume organic automatically has less pesticides. Unfortunately it’s not that simple. Organic agriculture allows for the use of pesticides, it’s just that they’re of natural not synthetic origin. To hit the point more squarely, let’s recap how the USDA talks about The National List of Allowed and Prohibited Substances:

In general, synthetic substances are prohibited for crop and livestock production unless specifically allowed and non-synthetic substances are allowed for crop and livestock production unless specifically prohibited.

Double speak aside, this study did not measure pesticide consumption in the diet directly. Instead they used frequency of organic food consumption as a proxy for pesticide exposure. Now, do I believe pesticide consumption is linked to increased cancer risk? Yes, most definitely. Do I want a way to know the pesticide levels in the foods I eat? Yes, most definitely. Is one surefire way to reduce my pesticide consumption to eat only organic foods? Uh…maybe. There’s lots of debate on this topic, coupled with a lack of information because databases can’t always cover all the pesticide residues possible across conventional and organic, nor can they reasonably cover every produce item from every growing region year round. It’s just not feasible. I at least take comfort in the 2016 finding from the USDA that 99.5% of samples tested had pesticide residues below EPA levels (and yes, I wonder about that other 0.5% too).


The Net

The net is that this one study is not going to change my purchasing behavior at all when it comes to choosing conventional versus organic foods.

The fact of the matter is that I do buy organic whenever possible because I believe in the grander proposition of what organic stands for, in theory at least. I also prefer to buy local whenever possible. Imagine my joy when I can get my hands on locally grown food and literally shake that farmer’s hand, even if what I’m buying may not be organic. And keep in mind some of the smaller growers do not go for organic certification because of the costs and hassles, and yet, they use organically-minded growing methods like crop rotation and integrated pest control.

Ultimately, I focus on brands that I trust. I would rather have responsibly grown food from start to finish that may not be organic, but is grown with care and sincere attention to factors like nutrient levels, taste and sustainability.

Oh, and show me a tool that uses blockchain or some whiz bang mobile tech to detect and report pesticide levels as I scan through the produce section of my supermarket, and I will be 100% on board! I’m ready and waiting.