Breast trans fatty acids

Opposing effects of certain individual fatty acids could have influenced the lack of a relationship between dietary fat and fat type with the risk of breast cancer. Well-conducted animal studies suggest that linoleic acid promotes development of mammary tumors, whereas saturated, monounsatu-rated, and trans fatty acids have little or no effect. In many cases, w-3 polyunsaturated fatty acids suppress tumor development. Conjugated linoleic acid (CLA) is the most potent anti-cancer fatty acid in that amounts of 1% or less of dietary fat can substantially inhibit the development of mammary tumors (Ip, 1997). 

Litin L, Sacks F. Trans-fatty-acid content of common foods. N Eng J Med 1993 329(26) 1969-1970. Lucas A, Morley R, Cole TJ, Lister G, Leeson-Payne C. Breast milk and subsequent intelligence quotient... 

Innis, S.M., and King, D.J. (1999) trans Fatty Acids in Human Milk are Inversely Associated with Concentrations of all-cw n-6 and n-3 Fatty Acids and Determine trans, but Not n-6 and n-3. Fatty Acids in Plasma Lipids of Breast-Fed Infants, Am. J. Clin. Nutr. 70, 383-390. 

Miwa and Yamamoto (31) described a simple and rapid method with high accuracy and reliability for the determination of C8 0-C22 6 fatty acids, which occur in esterified forms in dietary fats and oils and in living cells [the biological effects of routinely consumed fats and oils are of wide interest because of their impact on human health and nutrition (28,29), in particular, the ratio of cu-3 polyunsaturated fatty acid to w-6 polyunsaturated fatty acids (w-3/cu-6) seems to be associated with atherosclerosis and breast and colon cancers (30)]. They report improved separation of 29 saturated and mono- and polyunsaturated fatty acids (C8-C22), including cis-trans isomers and double-bond positional isomers, as hydrazides formed by direct derivatization with 2-nitrophenylhydrazine hydrochloride (2-NPH HC1) of saponified samples without extraction. The column consisted of a J sphere ODS-M 80 column (particle size 4 /xm, 250 X 4.6-mm ID), packed closely with spherical silica encapsulated to reach a carbon content of about 14% with end-capped octadecyl-bonded-spherical silica (ODS), maintained at 50°C. The solvent system was acetonitrile-water (86 14, v/v) maintained at pH 4-5 by adding 0.1 M hydrochloric acid with a flow rate of 2.0 ml/min. Separation was performed within only 22 min by a simple isocratic elution (Fig. 6). The resolution of double-bond positional isomers, such as y-linolenic ( >-6) and a-linolenic acid ( >-3) hydrazides and w-9, >-12, and >-15 eicosenoic acid hydrazides was achieved by use of this column. 

Trans-Isomers and Cancer A study conducted in postmenopausal women suggested an association between risk of breast cancer and the level of hydrogenated oil derived mono-frawi-fatty acids was stored in the adipose tissue (221). It was also found that frawi-fatty acid might cause colorectal neoplasia by interfering with the cell membrane function or eicosanoid metabolism (222). Increased adenoma prevalence was associated with the consumption of sweetened baked goods, oils, and condiments. 

Conjugated linoleic acids (CLAs) have been reported to be antitumoral fatty acids [9,10]. Two types of biologically active CLAs are known the cis-9,trans-ll isomer and the trans-l0,cis-l2 isomer. The former is the principal dietary form of CLA and was used in our experiment as a reference. Comparisons of cytotoxicity to breast cancer cells revealed that the cytotoxicity of 13-MTD was almost equivalent to that of CLA. 

An increased content of trans-unsaturated fatty acids is also found in some other mammals (such as kangaroos) where herbage is pre-digested by microorganisms in their digestive tract. Trans-unsaturated fatty acids partly pass into the milk (the predominant acid is vaccenic acid, but also present are elaidic acid, 3-5, and some other fatty acids). These fatty acids are ingested by humans as a part of their food and therefore occur in human depot fat and in breast milk. 

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