Study claims organic milk offers no nutritional advantages.

Issue 1 - May 21, 2010
Study of the Month

Scientists at Cornell University recently compared the nutritional profile of organic, conventional hormone-free milk, and milk from cows given recombinant bST. This is a synthetic version of the naturally occurring growth hormone, somatotropin.1 The conventional milk used in the study was similar to conventional milk in Canada, since, by law, no cow in Canada can be given growth hormones. Recombinant bST is banned not only in Canada, but also Australia, New Zealand and most of Europe, but is permitted in the United States.

The study was done because the researchers thought that consumers were confused over the value of milk labelled conventional, bST-free or organically produced, and were concerned that “some consumers may perceive that this type of specialty labelling indicates differences in the quality, nutritional value, or safety of dairy foods.” They therefore examined 292 pasteurized homogenized milk samples of all three types. They focused their investigation only on the fatty acid composition of the milks.

They did in fact find statistically significant differences between the different types of milk: Organic milk was slightly lower in trans and omega 6 fats and slightly higher in omega 3 fatty acids and saturated fat compared to conventionally produced or milk from bST-treated cows. However, although the differences reached statistical significance, the researchers considered the variations to be “minor and of no physiological importance when considering public health or dietary recommendations.”

It is interesting to see from this study that organically produced milk had a slight edge over conventionally produced milk in its fat profile. Previous studies have also shown improved omega 3 fatty acid content in organic milk.2 However, I would hazard a guess that there are other reasons consumers spend extra money on certified organic milk products instead of the cheaper, more widely available conventionally produced products, and not just for their fatty acid profile. Many prefer (myself included) to enjoy milk and milk products without consuming a cocktail of added man-made chemicals like herbicides and pesticides.

The correct research methodology here would have been first to ask the milk-buying public why they choose organic over conventional milk. Do they think it is better for them? And if so, is that because they think it’s more nutritious or are there other reasons? Is it the potential chemical content of conventionally produced milk that drives them to the organic aisle in the supermarket?  In a well planned research project this would be the first step – Phase 1. The answers would then be used in Phases 2 to investigate in the laboratory the differences between the two types of product.

It is significant that the present study, published in the Journal of Dairy Science, was supported by funding from Monsanto – the US-based multinational chemical company and the world’s leading producer of herbicides and genetically engineered seeds. They were also the chemical company that originally synthesized recombinant bST, although they sold this part of their business to the agricultural division of Eli Lilly several years ago. Could the source of their funding be one reason why researchers failed to explore all the reasons one might choose organic over non-organic produce?

One thing we can be sure of is that the research is sure to garner a few newspaper headlines stating there is no difference between organic and non-organic milk except for the price, thus detering more  consumers from choosing organic. Until I see research that thoroughly explores differences in the synthetic chemical content of organic and non-organic produce and shows the differences are “minor and of no physiological importance”, I’ll stick with organic!

1. O’Donnell AM, Spatny KP, Vicini JL, Bauman DE. Survey of the fatty acid composition of retail milk differing in label claims based on production management practices. J Dairy Sci. 2010 May;93(5):1918-25.

2.  Ellis KA et al. Comparing the fatty acid composition of organic and conventional milk. J Dairy Science 2006 Jun;89(6):1938-50.

Note: Articles or commentary in this newsletter are not intended as medical advice. Please check with your doctor if you have a concern about your health.
©2011 Aileen Buford-Mason. All rights reserved.


Study of the Month

Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. MORE >
Study claims organic milk offers no nutritional advantages. MORE >

In Brief

Genes determine how much vitamin D you need. MORE >
Scurvy in Toronto? MORE >