Organic Production Enhances Milk Nutritional Quality by Shifting Fatty Acid Composition: A United States–Wide, 18-Month Study

Indiana University, United States of America
PLoS ONE (Impact Factor: 3.23). 12/2013; 8(12):e82429. DOI: 10.1371/journal.pone.0082429
Source: PubMed


Over the last century, intakes of omega-6 (ω-6) fatty acids in Western diets have dramatically increased, while omega-3 (ω-3) intakes have fallen. Resulting ω-6/ω-3 intake ratios have risen to nutritionally undesirable levels, generally 10 to 15, compared to a possible optimal ratio near 2.3. We report results of the first large-scale, nationwide study of fatty acids in U.S. organic and conventional milk. Averaged over 12 months, organic milk contained 25% less ω-6 fatty acids and 62% more ω-3 fatty acids than conventional milk, yielding a 2.5-fold higher ω-6/ω-3 ratio in conventional compared to organic milk (5.77 vs. 2.28). All individual ω-3 fatty acid concentrations were higher in organic milk-α-linolenic acid (by 60%), eicosapentaenoic acid (32%), and docosapentaenoic acid (19%)-as was the concentration of conjugated linoleic acid (18%). We report mostly moderate regional and seasonal variability in milk fatty acid profiles. Hypothetical diets of adult women were modeled to assess milk fatty-acid-driven differences in overall dietary ω-6/ω-3 ratios. Diets varied according to three choices: high instead of moderate dairy consumption; organic vs. conventional dairy products; and reduced vs. typical consumption of ω-6 fatty acids. The three choices together would decrease the ω-6/ω-3 ratio among adult women by ∼80% of the total decrease needed to reach a target ratio of 2.3, with relative impact "switch to low ω-6 foods" > "switch to organic dairy products" ≈ "increase consumption of conventional dairy products." Based on recommended servings of dairy products and seafoods, dairy products supply far more α-linolenic acid than seafoods, about one-third as much eicosapentaenoic acid, and slightly more docosapentaenoic acid, but negligible docosahexaenoic acid. We conclude that consumers have viable options to reduce average ω-6/ω-3 intake ratios, thereby reducing or eliminating probable risk factors for a wide range of developmental and chronic health problems.

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Available from: Charles Benbrook, May 05, 2014
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    • "The Sustainable Agriculture Research Vol. 4, No. 3; 2015 authors of this study (Benbrook et al., 2013) on how organic production enhances milk quality conclude that " increasing reliance on pasture and forage-based feeds on dairy farms has considerable potential to improve the FA [fatty acid] profile of milk and dairy products " and " it is far more common – and indeed mandatory on certified organic farms in the U.S. – for pasture and forage-based feeds " and " improvements in the nutritional quality of milk … should improve long-term health status and outcomes, especially for pregnant women, infants, children, and those with elevated CVD [cardiovascular disease] risk. " Other studies have also reported differences in composition of animal products as a result of pasture feeding. "
    Sustainable Agriculture Research 06/2015; 4(3). DOI:10.5539/sar.v4n3p51
    • "Therefore, we can only assume that the circumstances in which these studies were undertaken reflect conditions expected of these countries. Holstein is the dominant breed in the United Kingdom, United States, and Denmark, representing 95, 90, and 72% of all dairy cows, respectively (Nygaard, 2007; Department for Environment, Food and Rural Affairs, 2010), but there is a trend toward non-Holstein breeds on organic dairy farms (Roderick and Burke, 2004; Sundberg et al., 2010; Benbrook et al., 2013). We can assume that the percentage of Holstein cows in the dairy herd varies between countries, as well as between organic and conventional farm systems; consequently, this will influence the FA composition in milk. "
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    ABSTRACT: Consumer perception of organic cow milk is associated with the assumption that organic milk differs from conventionally produced milk. The value associated with this difference justifies the premium retail price for organic milk. It includes the perceptions that organic dairy farming is kinder to the environment, animals, and people; that organic milk products are produced without the use of antibiotics, added hormones, synthetic chemicals, and genetic modification; and that they may have potential benefits for human health. Controlled studies investigating the differences between organic and conventionally produced milk have so far fallen short of a conclusion as to whether or not these differences exist. Controlled studies investigating whether differences exist between organic and conventionally produced milk have so far been largely equivocal due principally to the complexity of the research question and the number of factors that can influence milk composition. A main complication is that farming practices and their effects differ depending on country, region, year, and season between and within organic and conventional systems. Factors influencing milk composition (e.g., diet, breed, and stage of lactation) have been studied individually, whereas interactions between multiple factors have been largely ignored. Studies that fail to consider that factors other than the farming system (organic vs. conventional) could have caused or contributed to the reported differences in milk composition make it impossible to determine whether a system-related difference exists between organic and conventional milk. Milk fatty acid composition has been a central research area when comparing organic and conventional milk. Milk fatty acid composition has been a central research area when comparing organic and conventional milk largely because milk fatty acid profile responds rapidly and is very sensitive to changes in diet. Consequently, the effect of farming practices (high input vs. low input) rather than farming system (organic vs. conventional) determines milk fatty acid profile, and similar results are seen between low-input organic and low-input conventional milks. This confounds our ability to develop an analytical method to distinguish organic from conventionally produced milk and provide product verification. Lack of research on interactions between several influential factors and differences in trial complexity and consistency between studies (e.g., sampling period, sample size, reporting of experimental conditions) complicate data interpretation and prevent us from making unequivocal conclusions. The first part of this review provides a detailed summary of individual factors known to influence milk composition. The second part presents an overview of studies that have compared organic and conventional milk and discusses their findings within the framework of the various factors presented in part one. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
    Journal of Dairy Science 12/2014; 98(2). DOI:10.3168/jds.2014-8389 · 2.57 Impact Factor
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    • "Another crucial point is the fact that organic plant foods contain more polyphenols than similar conventional foods [23-26]. Organic animal fat also - for instance, milk and milk products - do have a higher n-3/n-6 ratio than conventional products [27-29]. Organic-fed animals mainly consume non-contaminated fresh grass with a high polyphenol content, rather than polyphenol-poor concentrates potentially contaminated with pesticides, and this may partly explain the favorable n-3/n-6 ratio [30,31]. "
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    ABSTRACT: In addition to genetic predisposition and sex hormone exposure, physical activity and a healthy diet play important roles in breast cancer (BC). Increased intake of omega-3 fatty acids (n-3) associated with decreased omega-6 (n-6), resulting in a higher n-3/n-6 ratio compared with the western diet, are inversely associated with BC risk, as shown by Yang et al. in their meta-analysis in BMC Cancer. High consumption of polyphenols and organic foods increase the n-3/n-6 ratio, and in turn may decrease BC risk. Intake of high fiber foods and foods with low glycemic index decreases insulin resistance and diabetes risk, and in turn may decrease BC risk. The modernized Mediterranean diet is an effective strategy for combining these recommendations, and this dietary pattern reduces overall cancer risk and specifically BC risk. High-risk women should also eliminate environmental endocrine disruptors, including those from foods. Drugs that decrease the n-3/n-6 ratio or that are suspected of increasing BC or diabetes risk should be used with great caution by high-risk women and women wishing to decrease their BC risk. Please see related article:
    BMC Medicine 03/2014; 12(1):54. DOI:10.1186/1741-7015-12-54 · 7.25 Impact Factor
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