Richard Bazinet is a professor of nutritional sciences at the University of Toronto and the Canada Research Chair in Brain Lipid Metabolism. Mark Schatzker is the author of Steak and The Dorito Effect.
What’s the difference between organic and conventional milk? We investigated and found none.
Headlines don’t get better than that. Last week, the Toronto Star published the result of an investigation into organic milk, which included laboratory analysis, and found that “the product is no different than cheaper regular milk.”
Canadians were rightly indignant. The news was “stunning,” according to one investigative reporter. The finding revealed “the power of the ‘health halo,’” tweeted a prominent CBC radio host, “believing that something brings you good when there’s no evidence that it does.”
The implication was clear: Those precious foodies were wrong all along. Conventional milk is just as good. Organic is overpriced and overrated. As bombshells go, the news that organic milk is all hype was downright delicious.
The news was also wrong.
Before we discuss exactly what the investigation got wrong, let’s take a moment to consider the scientific method. In science, sampling is considered extremely important. If a study uses a small number of samples, reaching definitive conclusions is impossible, because any observed effect, or lack of effect, may be simply due to chance
For example, if you asked 10 people in the departures lounge at Vancouver International Airport where they were traveling to, you might be astonished to discover that 70 per cent of were headed to Beijing. If you tested a larger sample – say, five thousand travelers, at all hours of the day, over the course of an entire year, and at various locations in the International Terminal, the Domestic Terminal and the South Terminal – you would find that the percentage of travelers headed to Beijing is, in fact, much lower.
To perform their analysis of nutritional differences, the Star analyzed milk from a single bag of Loblaw PC Organics versus a single bag of Neilson milk. In science, that isn’t considered data so much as an anecdote.
They found that both milks “showed the same proportions of Omega 3 and Omega 6 fats.” And from that, they came to the mind-boggling conclusion that “the cows producing Ontario’s organic milk are likely not grazing any more than conventional cows.”
The day this investigation was published, we attempted to replicate the findings. We purchased Loblaw PC Organics as well as Nielson milk. We also purchased and tested five other milks. Make no mistake, this is still a laughably small sample size. But our results match what numerous scientific studies have found, and they were revealing. We repeated our tests, just to be sure.
The organic milks we tested contained significantly different quantities of omega-6 and omega-3 fats. One organic milk had a ratio of omega-6s to omega-3s of 2:1. At the other end of the spectrum, one conventional milk had a ratio of 4.9:1.
This matches similar differences we have measured in samples of milk from Ontario and the rest of Canada over the past several years. Even in winter, our tests have found that the feed cows eat can have an effect on the milk they produce.
Like the Star’s investigation, we found that PC Organics and Nielsen had, curiously, the same ratio of the omega-6 to omega-3 ratio fats. But in our sample, the PC Organics milk had more of these polyunsaturated fats over all. Ratios, it seems, don’t always tell the whole story.
Do these differences in fats make one milk healthier than another? That is difficult to say with certainty. There will never be a long-term randomized control trial, in which one population of humans drinks conventional milk for 50 years and a similar population – which eats the same foods and leads the same lives – consumes organic milk.
This is the paradox of nutritional science. We will, similarly, never have such data for broccoli, carrots, spinach, red meat, potato chips or pork rinds.
The world is awash in ridiculous health claims and bogus products. Declaring the experts are all wrong can be satisfying. The zeal of organic milk enthusiasts, furthermore, can be excessive and annoying. Organic milk, however, is one of the few food products in the supermarket where the label is matched by differences both in farming and nutritional content.
You don’t have to drink organic milk. You don’t have to believe it’s healthier. But to say it’s “no different” is both wrong and unfair. Farmers deserve better. And so do consumers.
Source: The Globe and Mail