In the latest issue of the Journal of Dairy Science, a new study funded by the European Union compared the fat composition of retail milk produced through conventional methods and milk produced using an organic approach. The findings suggest that organic milk provides greater health benefits to humans than ordinary milk. 

Specifically, the study indicated that organic milk has much higher concentrations of beneficial and nutritionally desirable fatty acids than milk from conventional production systems. Additionally, organic milk was found to contain lower levels of harmful saturated fat. Although the overall fat content was similar in both types of milk tested, the organic milk showed evidence of more “healthy” fats.

The study, conducted by a team of researchers at Newcastle University’s School of Agriculture, Food and Rural Development, was a continuation of previous research that also compared organic and conventional milk. 

The earlier studies suggested that fatty acid and antioxidant profiles of milk from cows under organic management differ from those produced by cows under conventional management in the United Kingdom (UK) and elsewhere in Europe. However, those earlier studies were derived solely from farm-based studies. 

In explaining the importance of further research, Gillian Butler, project leader of the study, remarked, “We wanted to check if what we found on farms also applies to milk available in the shops.” 

The team began its research by collecting as many brands as possible of whole, fresh milk available in supermarkets and other retail outlets in northeast England between August 2006 and January 2008. Out of 124 milk types purchased, 88 samples from 22 brands, 12 from conventional production and 10 organic, were analyzed during the course of the study. The samples represented milk produced in both summer and winter seasons.

In addition to discovering the significant disparities between the fat composition of organic and conventional milk, the Newcastle University researchers reported other surprising conclusions. 

Interestingly, the study evidenced an unsuspected correlation between milk quality and climate. The results revealed that samples of non-organic milk collected during a particularly wet and cool UK summer and the following winter had a detrimental effect on the quality of the milk. According to the study, non-organic milk samples collected during a very poor UK summer had significantly higher saturated fat content and far less beneficial fatty acids than in a more “normal” year.

Importantly, however, researchers found that the samples of supermarket organic milk demonstrated higher levels of nutritionally beneficial fatty acids compared with “ordinary” milk, regardless of the time of year or weather conditions. 

In the previous study, which sampled milk directly from 25 various farms, it had been reported that greater health benefits were seen only during the summer months. However, this most recent Newcastle University study shows that those health benefits of organic milk are, in fact, present all year round, making it an overall healthier option.

Butler proffered that the considerable differences between organic and conventional milk are largely due to conventional farms’ lower reliance on grazing and overuse of nitrogen fertilizers, which often suppress the growth of nutrient-dense clover.

As reported by Newcastle University’s Press Office, “Organic dairying standards prescribe a reliance on forage, especially grazing, and, in the absence of nitrogen fertilizer, tend to encourage swards of red and white clover, which have been shown to alter the fatty acid intake and composition of milk.”

Remarking on the group’s findings, Emma Hockridge, Head of Policy at the Soil Association, said, “This groundbreaking research proves for the first time that people buying organic milk will be benefitting from the higher levels of beneficial fatty acids in organic milk through the whole year.”

Also worth noting was the greater consistency in quality seen between organic suppliers, whereas conventional milk was often found to be of varying quality. 

“We were surprised to see obvious differences between the conventional brands, with the more expensive ones not necessarily better,” said Butler. “Some brands–which promote their suppliers as wholesome and grazing on fresh pastures–actually sold milk that appeared to be from very intensive farms.”

Butler offered that “the results suggest greater uniformity of feeding practice on farms supplying organic milk since there were no brands which differed consistently in fat composition.” She added, “This implies a fairly uniform approach to feeding practiced across these suppliers.”

In light of the growing worldwide obesity epidemic as well as other health concerns, Butler, while discussing her research, recommended that opting for organic milk could be a step in the right direction. “We’re always being told to cut down on the saturated fat we consume and switching to organic milk and dairy products provides a natural way to increase our intake of nutritionally desirable fatty acids, vitamins and antioxidants without increasing our intake of less desirable fatty acids,” said Butler. 

She continued, “By choosing organic milk you can cut saturated fats by 30-50 percent and still get the same intake of beneficial fatty acids, as the omega-3 levels are higher but omega-6 is not, which helps to improve the crucial ratio between the two.”

The UK’s Food Standards Agency (FSA) has yet to endorse the health benefits of organic milk as suggested by this study. The findings conflict with a prior statement delivered by the agency that organic milk could contain high levels of omega-3 fatty acids but that they were of “limited health benefit.”

In a more recent address, a spokesman for the UK Department of Health, stated, “There is some evidence that organic milk may have higher levels of omega-3 fatty acids than conventional milk. However, the types of omega-3 fatty acids in organic milk are different to those found in oily fish. It is the omega-3 fatty acids in oily fish which have been shown to be beneficial in terms of heart disease.”