Organic, conventional show nutrient differences

Study finds higher percentage of the daily recommended requirements of very long chain fatty acids in organic whole milk

DRESDEN, Ont. — Studies published in the British Journal of Nutrition found differences in the nutritional composition of organic and conventionally-produced foods.

The two latest were published Feb. 16 and publicized by Newcastle University in the United Kingdom. They compare organic and conventional milk and meat.

The milk study is a systematic review of 170 papers on milk and dairy products.

“Overall, it can be concluded that a switch from intensive conventional to organic production standards will result in substantive improvements in milk fat composition,” the study states.

It was found organic milk has a better fatty acid profile with higher concentrations of nutritionally desirable polyunsaturated fatty acids and omega 3 fatty acids including close to a 60 percent higher concentration of very long chain omega 3 fatty acids.

Western diets tend to be deficient in these types of fatty acids. They’re especially important to pregnant and breast feeding women.

According to the study, a half litre of conventional, full fat milk will supply 11 percent of daily, recommended requirement of very long chain fatty acids while full fat organic milk will deliver 16 percent.

The study also found conventional milk had higher iodine levels. That’s a potential benefit in countries where iodized salt is not consumed but a potential concern where it is.

The meat study was less conclusive.

“We need substantially more, well designed studies and surveys before we can accurately estimate composition differences in meat from different farm animals and for many nutritionally important compounds,” the Newcastle University news release stated.

Still, the authors found that organically produced meat, especially beef, contains significantly higher concentrations of the desired polyunsaturated and omega 3 fatty acids. This supports the view that grazing and forage-based diets are responsible for the improvement.

The switch to grass-fed organic meat may allow meat consumption to be reduced by 30 percent while at the same time maintaining total omega 3 fatty acid intake. It was also found that organic meat also had less myristic and palmitic, saturated fatty acids which are potentially harmful.

“Overall, the present study indicates that organic livestock production may change the fatty acid profiles, and possibly other composition parameters, and that some of these changes . . . may be nutritionally desirable.”

However, some scientists questioned whether it was possible to achieve similar results simply by changing cattle feed.

An earlier study showed that organic crops and crop-based foods are up to 60 percent higher in a number of key antioxidants and contained less of the toxic metal cadmium compared to conventionally grown crops.

All three studies have been widely commented upon, with negative criticism in some instances. One common concern is that they do not provide enough evidence to show that the consumption of organic food will provide a significant health benefit.

The three studies were published by research teams led by Carlo Liefert with the School of Agriculture, Food and Rural Development at Newcastle University.

Meta-analysis, which first combines and then analyses all available data, was used for the studies.

It was noted that the Dangour et al. study published in the American Journal of Clinical Nutrition in 2009 uncovered a trend toward significantly higher levels of polyunsaturated and omega 3 fatty acids in organic meat and milk but the findings were not mentioned in the paper or accompanying press release.

The Dangour study concludes, “. . . there is no evidence of a difference in nutrient quality between organically and conventionally produced foodstuffs. The small differences in nutrient content are biologically plausible and mostly relate to differences in production methods . . . (but) are unlikely to be of public health relevance.”

The entire database generated and used for the studies is available at no cost on the Newcastle University website.

The Dangour study is also available online.

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