Citywatch: Getting to the right question on the nutrient benefits of organic food
Citywatch: Whether it’s action or traction in the food world, cities are stepping up to the plate. The world is fast going urban, as are challenges of social, economic and environmental well being. Citywatch is crucial to Worldwatch. Wayne Roberts, retired manager of the world-renowned Toronto Food Policy Council, has his eye out for the future of food in the city. Click here to read more from Wayne.
The international media had a field day headlining a Stanford university dissing significant nutritional benefits of organic food. I hope it’s not too late for me to ask a few questions that might steer the debate in a more useful direction.
I would like the media to explain why a study that was not based on either original research or professional expertise was considered so significant.
The paper, published in the Annals of Internal Medicine, is strictly a “meta-analysis,” combining some of the findings of some 200 other scientists’ publications over the years. It is the ninth such paper to come out in a decade, and the fourth to turn thumbs down on organic claims to significant superiority in the nutritional realm – not exactly trail-blazing stuff. Nor, considering the ability of writers to cherry pick various findings from different individual studies, does a meta-analysis inherently prove much more than ability to cherry pick. That’s why new hard research, rather than summaries of old research, is usually the stuff of news stories.
I would also like to ask why no-one checked the qualifications of this 12-person team, which was granted immediate credibility, despite the absence of a professional nutritionist, agrologist or bio-medical specialist. One is a librarian, a few are graduate students, several are medical doctors who specialize in such fields as infectious disease, bio-terrorism, diagnosis or HIV, one is a mathematician, one an administrator, one a research assistant.
The heavy-hitter on the team is Igram Olkin, at 88 a retired professor in statistics. Stanford University media releases cite his renown as a specialist in meta-analysis, without mentioning that his name is batted around as a paid witness on statistics for the tobacco industry. Given that the Stanford team’s use of statistics is subjected to withering criticism by organic advocate and academic Charles Benbrook, it’s odd no mainstream reporter checked to see if where there’s smoke, there’s fire.
It’s also a bit odd that no-one asked what an article on nutritional merits of organic foods was doing in a medical journal, given that docs have minimal training, credentials or interest in this field – although maybe I’ve just answered my own question.
One of the first things I learned when researching for my first serious food book some 15 years ago was that the relation between organic and nutrition does not compute.
Nutritional levels vary according to a host of factors. One big one is the quality of soil long before anyone farmed it organically or conventionally (no history of volcanoes in New York means no rich volcanic ash in the soil, for example). Another factor that has little to do with organic or conventional is when the crop was picked (tomatoes get most of their vitamin C as they turn red, not when they’re hard and green, which is when they get picked by machines).
The list of crucial questions and variables keeps growing: how long was the produce in a truck or store, under what conditions was the food stored, how was the food prepared (some vitamins are destroyed by heat, some nutrients only become available when heated).
It’s quite likely that healthier and stronger plants grow on organically-managed soils, without any help from synthetic fertilizers or pesticides. But that’s no guarantee that the plants bulked up on more nutrients. Organic or not, plants work to meet their own survival needs, not ours, and the optimum level of vitamin B needed by a particular plant may or may not work best for humans. That’s why people choose particular plants if they’re looking for high doses of particular nutrients.
Put the whole mix together, and a study based on analysis of a conventional ruby red tomato, lightly cooked immediately after picking, will probably show more nutrients than an organic tomato picked green from an industrial organic farm a week ago, hauled across the continent on a truck, and left to sit at a salad bar, for example. These are the kinds of things that affect nutrient levels, and anyone who knows more about nutrition than editors of a conventional medical journal would hear alarms ringing in their ears if writers started making a big case about nutrient differences with or without organic.
This is why nutrition expert Marion Nestle started her blog item on the controversy by saying “sigh,” as in “have I not explained this a hundred times already?” Organic advocates rarely make a nutritional claim, she points out. So the Stanford article is knocking down its own straw man.
With dairy and meat, new evidence suggests that a key issue is how animals are treated. Still- controversial studies suggest that grass-fed animals have more nutritious milk and meat than animals fed corn and soy – no matter whether organic or conventional. That’s only logical, given that most animals evolved to eat grass rather than corn or soy, which are good for bulking up fast, but not necessarily so good for complex nutrients.
Organic scores well, even in the Stanford study, in terms of pesticide residue, which is as important to personal health as nutrients. Almost no-one is suffering from scurvy, rickets or wasting in North America or Europe, where the Stanford study got a lot of media, but breast, prostate, colon and bladder cancers have affected almost every family. A strong case can be made that toxic residues from pesticides, brought into the body by food, are implicated in these cancers. So this isn’t exactly a minor selling point for organics.
On the question of toxins, however, I’m also intrigued that there are any – not 30 per cent less, but any -- pesticide residues on organic. That can only mean that the toxins from conventional fields migrated by air, rain or water table to organic fields, and who knows where else.
Why didn’t that set off media alarm bells? It means that people who pay extra for organic are still getting toxic residues that rightfully belong to the people who produced and bought conventional food.
This is an issue worthy of a meta-analysis. Are organic consumers dupes, taking the toxic bullet for people who saved money thanks to pesticides. Is it fair that some farmers get to cut their production costs by spreading toxins throughout the environment?
Since the Stanford team is asking whether organic costs more when it doesn’t deliver more nutrients, why doesn’t the team also ask the flip side of the question -- whether conventional gets to charge less because the toxic load is passed on to everyone?
That question gets to the penultimate tricky question of agricultural prices. Why do some get to offload costs to the environment for free, while those who contribute to a safer environment get no fee compensating them for their extra work on behalf of the public good? If an environmental fee was paid to the farmer producing the environmental service, then all farmers would compete on an even playing field, and no academics would ever have to ask whether organic delivers more value for the money.
Why doesn’t the Stanford team, or any of the media following their study, ask that? There I go again, answering my own question.
What do you think? Leave a comment below.
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