Organic Diet and Fatty Acids in Breast Milk

Background and methodology
The aim of this study was to find out whether incorporating organic dairy and meat products in a nursing mother’s diet affects the fatty acid content in her breast milk. There is experimental evidence suggesting that these fatty acids (conjugated linoleic acid isomers, or CLA, and trans-vaccenic acid, TVA) might have anti-carcinogenic, anti-atherosclerotic, anti-diabetic and immune-modulating effects, as well as a favorable influence on body fat composition, i.e. on the proportion of fat tissue to muscle mass. Milk samples from 312 breast-feeding mothers participating in the KOALA Birth Cohort Study were analyzed. The participants had documented varying lifestyles in relation to the use of conventional or organic products. Breast milk samples were collected one month postpartum and analyzed for fatty acid composition.

The content of rumenic acid (the main CLA) increased in a statistically significant way while going from a conventional diet to a moderately organic diet and to a strict organic diet. The levels of TVA were augmented among the participants with a moderately organic diet and those with a strict organic diet, in comparison with the conventional group. After adjusting for co-variables (recruitment group, maternal age, maternal education, use of supplements and season), statistical significance was retained in the group of the strict organic dairy users. Hence, the levels of CLA and TVA in human milk can be modulated if breast-feeding mothers replace conventional dairy and/or meat products by organic ones. This study indicated that the levels of both rumenic acid and TVA in human breast milk were higher in the case of mothers following a diet that contained organic dairy and meat products, in comparison with mothers consuming a conventional diet.


Rist, L., Mueller, A., Barthel, C., Snijders, B., Jansen, M., Simoes-Wuest, A. P., Huber, M., Kummeling, I., von Mandach, H. Steinhart, U., and Thijs, C. (2007). Influence of organic diet on the amount of conjugated linoleic acids in breast milk of lactating women in the Netherlands. British Journal of Nutrition, 97(4), 735-743. Available on-line at: