Enhancing the fatty acid profile of milk through forage-based rations, with nutrition modeling of diet outcomes.

Food Sci Nutr. 2018 Feb 28;6(3):681-700. doi: 10.1002/fsn3.610. eCollection 2018 May. Benbrook CM1,2, Davis DR3, Heins BJ4, Latif MA5, Leifert C6, Peterman L5, Butler G7, Faergeman O8, Abel-Caines S5, Baranski M6. Author information 1 Bloomberg School of Public Health Johns Hopkins University Baltimore MD USA. 2 Benbrook Consulting Services Troy OR USA. 3 Biochemical Institute University of Texas at Austin Austin TX USA. 4 West Central Research and Outreach Center University of Minnesota Morris MN USA. 5 Organic Valley/CROPP Cooperative Lafarge WI USA. 6 Centre for Organics Research Southern Cross University Lismore NSW Australia. 7 School of Natural and Environmental Science Newcastle University Newcastle upon Tyne UK. 8 Department of Cardiology Aarhus University Hospital Aarhus Denmark. Abstract Consumer demand for milk and meat from grass-fed cattle is growing, driven mostly by perceived health benefits and concerns about animal welfare. In a U. S.-wide study of 1,163 milk samples collected over 3 years, we quantified the fatty acid profile in milk from cows fed a nearly 100% forage-based diet (grassmilk) and compared it to profiles from a similar nationwide study of milk from cows under conventional and organic management. We also explored how much the observed differences might help reverse the large changes in fatty acid intakes that have occurred in the United States over the last century. Key features of the fatty acid profile of milk fat include its omega-6/omega-3 ratio (lower is desirable), and amounts of total omega-3, conjugated linoleic acid, and long-chain omega-3 polyunsaturated fatty acids. For each, we find that grassmilk is markedly different than both organic and conventional milk. The omega-6/omega-3 ratios were, respectively, 0.95, 2.28, and 5.77 in grassmilk, organic, and conventional milk; total omega-3 levels were 0.049, 0.032, and 0.020 g/100 g milk; total conjugated linoleic acid levels were 0.043, 0.023, and 0.019 g/100 g milk; and eicosapentaenoic acid levels were 0.0036, 0.0033, and 0.0025 g/100 g milk. Because of often high per-capita dairy consumption relative to most other sources of omega-3 fatty acids and conjugated linoleic acid, these differences in grassmilk can help restore a historical balance of fatty acids and potentially reduce the risk of cardiovascular and other metabolic diseases. Although oily fish have superior concentrations of long-chain omega-3 fatty acids, most fish have low levels of α-linolenic acid (the major omega-3), and an omega-6/omega-3 ratio near 7. Moreover, fish is not consumed regularly, or at all, by ~70% of the U. S. POPULATION: KEYWORDS: GrassmilkTM; dairy farming; dairy fatty acids; grass milk; omega‐6/omega‐3 ratio; organic milk PMID: 29876120 PMCID: PMC5980250 DOI: 10.1002/fsn3.610 Free PMC Article