Archivos de Zootecnia ISSN: 0004-0592 [email protected] Universidad de Córdoba España Carrara, E.R.; Gaya, L.G.; Mourão, G.B. Fatty acid profile in bovine milk: Its role in human health and modification by selection Archivos de Zootecnia, vol. 66, núm. 253, 2017, pp. 151-158 Universidad de Córdoba Córdoba, España Available in: http://www.redalyc.org/articulo.oa?id=49551221022 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Archivos de Zootecnia Journal website: https://www.uco.es/ucopress/az/index.php/az/ REVIEW Fatty acid profile in bovine milk: Its role in human health and modification by selection Carrara, E.R.1@; Gaya, L.G.1 and Mourão, G.B.2 1Federal University of São João del-Rei. São João del-Rei. Minas Gerais. Brazil. 2“Luiz de Queiroz” College of Agriculture. University of São Paulo. Piracicaba. São Paulo. Brazil. SUMMARY ADDITIONAL KEYWORDS Milk fat is predominantly composed of fatty acids. Bovine milk shows a high concentration Dairy cattle. of saturated fatty acids, some of them associated with an increase in the risk of cardiovascular diseases in human beings. However, many of these have neutral or positive effects on health, as Fat milk. well as some unsaturated fatty acids do. The fat profile of bovine milk can be changed by lipid Genetic parameters. supplementation in a fast and efficient way, but genetic variation is also verified in this profile and genetic breeding becomes more relevant than supplementation for presenting permanent results. This bibliographic review has the objective of gathering the main results referring to the genetic aspects of fatty acids profile in bovine milk. Perfil de ácidos graxos no leite bovino: seu papel na saúde humana e sua modificação por seleção PALAVRAS-CHAVE ADICIONAIS RESUMO Gado de leite. A gordura do leite é composta, predominantemente, por ácidos graxos. O leite bovino Gordura do leite. apresenta alta concentração de ácidos graxos saturados, alguns associados ao aumento Parâmetros genéticos. do risco de doenças cardiovasculares em humanos. Porém, muitos desses, possuem efeitos neutros ou positivos sobre a saúde, assim como alguns ácidos graxos insaturados. O perfil da gordura do leite de bovinos pode ser alterado por suplementação lipídica de maneira rápida e eficiente, porém, verifica-se também variação genética nesse perfil e o melhoramento gené- tico se torna mais relevante do que a suplementação por apresentar resultados permanentes. Esta revisão de literatura teve como objetivo reunir os principais resultados referentes aos aspectos genéticos do perfil de ácidos graxos no leite de bovinos. INFORMACIÓN Cronología del artículo. Recibido/Received: 12.02.2016 Aceptado/Accepted: 09.09.2016 On-line: 15.01.2017 Correspondencia a los autores/Contact e-mail: [email protected] INTRODUCTION lipid supplementation (Santos et al., 2001). This altera- tion can be induced by feed because of the amount of The major part of fat in bovine milk is composed unsaturated fatty acids contained in the provided lipid by triacylglycerols, consisting of three fatty acids and and by its release rate in rumen; therefore, modifying one glycerol molecule. Such fatty acids are predomi- the metabolism, it is possible to obtain a different fatty nantly in saturated form (Eifert, 2006), which are as- acids profile. The toxicity of unsaturated fatty acids sociated with the increase of the risk of cardiovas- through acting upon some bacteria species, leads to cular diseases in human beings (Santos et al., 2013). modification of ruminal microbiota. The use of animal However, such effects are only related to lauric (C12:0), breeding stands out among attempts of modifications myristic (C14:0), and palmitic (C16:0) fatty acid, while of this profile, since there is a genetic variation in fat the others have neutral or positive effects on human milk composition and between bovine breeds (Soyeurt health (Mensink et al., 2003). Regarding the unsatura- et al., 2006). Furthermore, even diet supplementation ted fatty acids, those which stand out are the oleic acid being the fastest and most efficient way to modify fatty (C18:1 cis-9) and the isomers of conjugated linoleic acid acids composition in cow milk (Jenkins & McGuire, (CLA), related to the cholesterol reduction and to the 2006), animal breeding becomes more relevant becau- anticarcinogenic effects respectively (Haug et al., 2007). se it shows permanent advances, despite its slowness The fat profile of bovine milk can be altered by dietary and long term planning. Moreover, recent researches Arch. Zootec. 66 (253): 151-158. 2017 CARRARA, GAYA AND MOURÃO by Bastin et al. (2013) and Bilal et al. (2014) have shown There are reports that the lauric fatty acid (C12:0) can medium and high heritability for several fatty acids in have antibacterial effects (Sun et al., 2002) and might Holstein cow milk, which suggests a feasible selection act as anticaries and antiplaque agent (Sun et al., 2003). to those components. Thus, studies related to genetic The increase in cardiovascular diseases among human behavior of fatty acids profile in milk might allow the beings is related to lauric (C12:0), myristic (C14:0), and use of tools aiming to improve such profile and promo- palmitic fatty acids, because of low density lipopro- te better milk quality. tein (LDL) and high density lipoprotein (HDL), both of them linked to increased cholesterol. Other milk- Therefore, the objective of this revision was to saturated fatty acids have neutral or positive effect on gather the main results regarding the influence of ani- health (Mensink et al., 2003). Stearic fatty acid (C18:0) mal genetics on fatty acids profile of bovine milk. is not regarded as a promoter of increased cholesterol CHEMICAL COMPOSITION OF BOVINE MILK concentration (Grundy, 1994). Bovine milk is composed of water (87%), lactose In relation to unsaturated fatty acids, the trans form (4.9%), fat (3.5%), protein (3.1%), minerals and vitam- shows worse effect in human health than the satura- ins in smaller proportions (Jensen, 1995). It is necessary ted ones, since it increases the levels of what is called to consider milk composition because it is important to “bad” cholesterol (LDL) and it decreases the levels of determine its nutritional quality, capacity of being pro- “good” cholesterol, HDL. However, only small amou- cessed and consumption by humans. It varies influen- nts of natural trans fats are found in meat and ruminant ced by multiple factors (Silva, 1997). Around 60% of the milk, and they are not associated with cardiovascular variation in milk composition is due to genetic aspects diseases (Mozaffarian et al., 2009). The C16:1 trans-7, a and environmental aspects such as nutrition, climate, trans fatty acid that performs as a biomarker of milk diseases, and milk storage (Kitchen, 1981; Shearer et al., fat, relates itself to a lower risk of diabetes mellitus 1992) causing rest. development and sudden cardiac death (Mozaffarian, 2015b). Among bovine milk components, fat presents hig- her variation rates from 3.2% to 6%. About 98% of cow It is important to highlight that there is great dis- milk lipid fraction is composed by triacylglycerol. Ac- tinction between trans fatty acids that are formed by cording to description by Hayes and Khosla (1992), the animals and those industrially produced. Products combination of lipids in milk that is more favorable to originated from ruminants show a concentration from human health stands for 30% of saturated fatty acids, 3 to 8% of trans fatty acids in relation to total fatty 60% of monounsatured fatty, and 10% of polyunsatu- acids, while industrialized products show 10 to 40% rated fatty acids. The highest concentration of bovine concentration (Martinez, 2009). High levels of indus- milk is fatty acids (Eifert, 2006), but there are only trially produced trans fatty acids can be consumed three of them associated with increase in the risk of through partially hydrogenated vegetable oil, which cardiovascular diseases in human beings: lauric acid; usually contain from 30 to 60% of trans fatty acids myristic acid; and palmitic acid (Mensink et al., 2013). (Mozaffarian, 2016). Besides a higher concentration of Researches indicate that, in the milk fat profile, there trans fatty acids in the total fatty acids, industrializa- are compounds that are beneficial to human health tion also causes the preferential production of elaidic (Eifert, 2006), such as some saturated and unsaturated acid (C18:1 trans-9). Rumen bacteria, mainly generate fatty acids, as described below. vaccenic acid (C18:1 trans-11), a precursor of a specific type of conjugated linoleic acid (CLA) (Martinez, 2009). FATTY ACIDS COMPOSITION AND HUMAN HEALTH The ingestion of trans fatty acids from partially hydro- Researches highlight the increase in risk of cardio- genated oils is consistently associated with the risk of vascular diseases (Grimsgaard et al., 1999; Zheng et cardiovascular diseases and sudden death (Mozaffa- al., 1999; Yli-Jama et al., 2002; Matsumoto et al., 2013) rian et al., 2006; Mente et al., 2009). when there is fatty acid ingestion, but not all studies There are unsaturated fats that have positive effects present the same ideas (Lemaitre et al., 2010; Wu et al., on human health. Polyunsaturated ω-3 fatty acids can 2011). Saturated fat covers