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Many studies find differences between organic and conventional foods, with more favorable results for organic foods (e.g. better nutritionally, lower pesticide residues). A study by Emory University researchers that analyzed samples of conventional and organic milk from different regions of the US adds to the list. They found  that the samples of conventional milk contained pesticides, antibiotics, and synthetic growth hormones, but none of these were found in organic milk.

The pesticide levels in the conventional milk varied among the samples, but included frequently used pesticides such as atrazine, permethrin, cypermethrin, chloroyrifos, and diazinon. Chlorpyrifos, found in 59% of the conventional milk samples, is the pesticide that scientists absolutely want banned because of its neurotoxic effects, especially on developing babies and children.  They also found that antibiotic residue levels in conventional milk samples surpassed federal limits for amoxicillin (3%), and illegal sulfamethazine (37%) and sulfathiazole (26%). Yikes!

These are important findings because milk is a staple in the diet of many people, especially children. By the way, international milk also can have pesticide and drug residues (e.g. Israel).

But not all organic milk is equal. Unfortunately a number of big so-called organic dairy farms (15,000 to 20,000 cows) are basically factory farms (e.g. Aurora Organic Dairy, Horizon) - they exploit loopholes in organic regulations, as well as deliberately not follow some organic standards. However, even low-quality organic milk has been shown to contain no residues of antibiotics and toxic pesticides - it's just that their milk nutritional profile is different than that of grass-fed organic cows.

Organic milk cows are supposed to be outside grazing during the growing season, at least 120 days a year - thus real organic milk is from "grass-fed" cows. Grass-fed cows (but not conventional and factory-farm organic cows) tend to produce milk with elevated levels of two types of fat: conjugated linoleic acid (CLA) and omega-3 fat known as alpha-linolenic acid. Both have been associated with health benefits in humans, although the amounts found in milk are relatively small. Another type of fat called linoleic acid, (an omega-6 fat), tends to be lower in milk that is from pasture-fed cows.

The Cornucopia Institute has dairy scorecards and rankings of major organic milk brands, as well as other organic foods (e.g. poultry, cereal, eggs). Cornucopia is an organic agriculture watchdog group - an excellent resource to help you choose organic foods.

Some excerpts from the Jean A. Welsh et al. study in the journal Public Health Nutrition: Production-related contaminants (pesticides, antibiotics and hormones) in organic and conventionally produced milk samples sold in the USA

Conclusions: Current-use antibiotics and pesticides were undetectable in organic but prevalent in conventionally produced milk samples, with multiple samples exceeding federal limits. Higher bGH and IGF-1 levels in conventional milk suggest the presence of synthetic growth hormone. Further research is needed to understand the impact of these differences, if any, on consumers.   ...continue reading "Organic Milk Does Not Contain Toxic Pesticides Found In Conventional Milk"

 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:

New study finds clear differences between organic and non-organic milk and meat

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)