Got Organic Milk?

Abstract

Source: Benbrook CM, Butler G, Latif MA, et al. Organic production enhances milk nutritional quality by shifting fatty acid composition: a United States-wide, 18-month study. PLoSOne. 2013; 8(12): e82429; doi: 10.1371/journal.pone.0082429Investigators from multiple institutions in the United States and United Kingdom conducted a study comparing the fatty acid (FA) composition in organic and conventional milk that is commercially available in the United States. The investigators assayed organic and conventional milk from 14 commercial processors located in 7 geographical regions. Monthly samples were assayed over an 18-month period from each of the processors. The primary study outcome was a comparison of the ω-6:ω-3 FA ratio among the samples of conventional and organic milks. This outcome was chosen because there is evidence that a lower ω-6:ω-3 FA ratio reduces the risk for various health conditions such as cardiovascular disease, stroke, and diabetes.1,2 Concentrations of specific ω-6 FAs and ω-3 FAs in the 2 types of milk were also compared.Assays of 218 samples of organic milk and 160 conventional samples were analyzed. Moderate seasonal and regional variability in milk FA profiles was found. On average, conventional milk had a 2.5- fold higher ω-6:ω-3 ratio compared to organic milk (ω-6:ω-3 ratios of 5.77 and 2.28, respectively, P < .0001). As compared to conventional milk, organic milk had higher concentrations of several ω-3 FAs, including α-linoleic (60% greater), eicosapentanoic (32% greater), and docosahexanoic (19% greater).The authors conclude that consumers have viable options to reduce average ω-6:ω-3 intake ratios, thereby potentially reducing the risk of a wide range of health problems.Drs Cerezo and LeLeiko have disclosed no financial relationship relevant to this commentary. The commentary does not contain a discussion of an unapproved/investigative use of a commercial product/deviceMilk products are well known sources of essential FAs, particularly the ω-3 FAs. The quality and balance of ω-6 and ω-3 FAs are important in maintaining the health of various organ systems. There is general agreement about the desirability of increasing ω-3 at the expense of ω-6 FAs. Numerous studies have shown the cardioprotective and anti-inflammatory effects of ω-3 FAs.1,2 However, results of the Omega 3 Trial to date have not shown any true benefit, and unequivocal health benefits have not been shown in clinical trials.3 This raises the important question of whether targeting the ω-6:ω-3 ratio results in a real and measurable health benefit.This is the first large-scale study to assess the difference in the FA profile of organic and conventional milk. The authors, who include employees of a dairy cooperative with a presumed interest in showing the superiority of organic milk, provide interesting background information on some regulations governing the food industry. For example, the US National Organic Program requires that lactating cows on certified organic farms receive at least 30% of daily Dry Matter Intake from pasture during that portion of the year when grasses and legumes are actively growing, a time period that must be at least 120 days per year. It does seem important and logical that the resulting milk will be a different product from that of nonregulated farm animals, who feed primarily on grain. The analysis by these authors indicates that overall, there appears to be a much healthier ratio of ω-6:ω-3 FA in organic milk. The authors conclude that increasing consumption of dairy products as a whole, especially those from dairy farms that optimize pasture- and forage-based feeds, combined with decreased consumption of ω-6-containing foods, will help attain an optimal target ratio of ω-6:ω-3 FAs.Even though potential health benefits from such change or “improvement” is unclear, the authors convinced us that organic milk has a “healthier” FA profile and made a compelling case for spending the extra money on organic dairy products.