Two new papers just published in the British Journal of Nutrition are meta-analyses of existing studies that compare conventional vs organic milk, and conventional vs organic red meat. Both studies found clear differences between organic meat and milk compared to conventional milk and meat, with the organic milk and meat best health-wise, especially due to differences in fatty acids. The researchers stated: "organic bovine (cow) milk has a more desirable fatty acid composition than conventional milk". Some of the differences may be due to organic milk and beef coming from cattle that graze on grass (organic farming standards require grazing/forage-based diets) , while most conventional milk and beef come from cows subsisting on grain. Beneficial omega-3 is much more prevalent in grass than in grain, which is why organic livestock and milk also contain higher levels, while omega-6 levels were lower in organic meat and dairy.
The researchers did not look at antioxidant, vitamin and mineral concentrations between the meat groups because there weren't enough studies to look at. Two years ago, Dr. Leifert led a similar review for fruits and vegetables that found organic produce had higher levels of some antioxidants and less pesticide residue than conventionally grown crops. From Medical Xpress:
In the largest study of its kind, an international team of experts led by Newcastle University, UK, has shown that both organic milk and meat contain around 50% more beneficial omega-3 fatty acids than conventionally produced products. Analyzing data from around the world, the team reviewed 196 papers on milk and 67 papers on meat and found clear differences between organic and conventional milk and meat, especially in terms of fatty acid composition, and the concentrations of certain essential minerals and antioxidants.
Publishing their findings today in the British Journal of Nutrition, the team say the data show a switch to organic meat and milk would go some way towards increasing our intake of nutritionally important fatty acids.Chris Seal, Professor of Food and Human Nutrition at Newcastle University explains: "Omega-3s are linked to reductions in cardiovascular disease, improved neurological development and function, and better immune function.
The systematic literature reviews analysed data from around the world and found that organic milk and meat have more desirable fat profiles than conventional milk and meat. Most importantly, a switch from conventional to organic would raise omega-3 fat intake without increasing calories and undesirable saturated fat....Other positive changes in fat profiles included lower levels of myristic and palmitic acid in organic meat and a lower omega-3/omega-6 ratio in organic milk. Higher levels of fat soluble vitamins such as vitamin E and carotenoids and 40% more CLA in organic milk were also observed. The study showed that the more desirable fat profiles in organic milk were closely linked to outdoor grazing and low concentrate feeding in dairy diets, as prescribed by organic farming standards.
The two new systematic literature reviews also describe recently published results from several mother and child cohort studies linking organic milk and dairy product consumption to a reduced risk of certain diseases. This included reduced risks of eczema in babies.
"Several of these differences stem from organic livestock production and are brought about by differences in production intensity, with outdoor-reared, grass-fed animals producing milk and meat that is consistently higher in desirable fatty acids such as the omega-3s, and lower in fatty acids that can promote heart disease and other chronic diseases." The study also found 74% more iodine in conventional milk....Iodine fortification of cattle feeds is also widely used to increase iodine concentrations in both organic and conventional milk.
The work builds on a previous study by the team - involving experts from the UK, US, France, Italy, Switzerland, Norway and Poland - investigating the composition of organic and conventionally-grown crops. This previous study - also published in the British Journal of Nutrition - showed that organic crops and crop-based foods are up to 60% higher in a number of key antioxidants than conventionally-grown crops and contained less of the toxic metal cadmium.
"We have shown without doubt there are composition differences between organic and conventional food. Taken together, the three studies on crops, meat and milk suggest that a switch to organic fruit, vegetables, meat and dairy products would provide significantly higher amounts of dietary antioxidants and omega-3 fatty acids," concludes Professor Leifert. (The 2 studies: the milk study, the meat study)