By Caroline Scott-Thomas, 31-May-2010
Are organic foods healthier? The sad truth is that nearly 100,000 studies later, we just don't know. Meanwhile, this lack of certainty presents major business opportunities for the organic food industry.
The science examining the comparative health effects of organic and conventionally grown foods is shockingly woolly. Much less woolly is the recommendation of a US government panel earlier this month to choose organic foods – or at least wash conventionally grown produce – because you know what, we just don’t know whether all those chemical residues could cause cancer. There may be no evidence that they are harmful, but nor is there evidence that they are not harmful. What an extraordinary admission.
It is this lack of evidence one way or another that could be a boon for the organic food industry, as consumers increasingly take a ‘better safe than sorry’ approach to their diets. Organic food might be healthier, after all, and conventionally grown foods might cause cancer.
So what’s going on?
The latest review of research comparing the relative nutritional value of organic and conventionally grown foods was published in the American Journal of Clinical Nutrition last week. Of an impressive 98,727 articles published over the past 50 years, the researchers found only 12 that they deemed relevant. They concluded that the existing evidence is not sufficient to suggest that organic food is any healthier. The same researchers came to the same conclusion last year, when they looked at 162 studies. But so what?
Ignore the headlines that shout ‘Organics not really healthier’ or ‘Organics are waste of money’ – the truth is that the most significant finding of these reviews is that there is a paucity of well-conducted research.
A large number of studies were excluded because they did not specify an organic certifying body; there was no information on the cultivar or livestock breed; no statement of which nutrient or nutritionally relevant substance was reviewed; no information on statistical methods; or no information on laboratory methods.
“A surprising and important finding of this review is the extremely limited nature of the evidence base on this subject, both in terms of the number and quality of studies,” the authors wrote.
Surprising and important indeed.
However, in my view, examining whether an organic carrot contains more antioxidants than its conventionally grown cousin rather misses the point. Many people do not buy organic foods because they think they are more nutritious (although of course some do, and will continue to do so, whether or not there is scientific evidence to validate their choice).
No, a large number of people choose organics because they are worried about chemical residues, both for their effects on health and on the environment. And that’s where the lack of evidence becomes rather startling.
The US President’s Cancer Panel’s recommendation to choose organic (or wash conventional produce) was based on a similarly surprising and important lack of research on the safety of many of the more than 80,000 commercially available synthetic chemicals in the US food supply. Cancers resulting from environmental factors could be “grossly underestimated”, the panel said, because few of those chemicals are regulated.
In the United States buying certified organic food is also the surest way to avoid growth hormones or genetically modified ingredients, other elements of the food supply with an arguably small amount of convincing research. Organic food suddenly seems very attractive indeed – and the organic sector continues to reap the benefits of a lack of clear evidence, as sales continue to grow.
So the debate over whether organic foods bestow real health benefits rumbles on.
As for me, I would rather opt out of an experiment that could find a dietary link with cancer rates thirty years down the line.
As I scrub my conventionally grown fruit and veg, I can only hope that there may be answers in the next 100,000 studies.
Caroline Scott-Thomas is a journalist specializing in the food industry. Prior to completing a Masters degree in journalism at Edinburgh's Napier University, she had spent five years working as a chef.