Trans mono- and polyunsaturated fatty acids in human milk

Area of Science:

• Nutritional Biochemistry
• Food Chemistry
• Human Physiology

Background:

• Trans fatty acids (TFAs) are unsaturated fatty acids with a trans configuration around at least one double bond.
• Human milk is a primary source of nutrition for newborns, and its composition can be influenced by maternal diet.
• Identifying TFAs in human milk is crucial for understanding infant exposure and potential health implications.

Purpose of the Study:

• To identify and quantify trans isomers of C18 fatty acids in human milk samples.
• To determine the prevalence and types of trans mono- and polyunsaturated fatty acids (PUFAs) in human milk.
• To investigate potential sources and dietary influences on TFA content in human milk.

Main Methods:

• Collection of ten human milk samples from French women.
• Analysis of fatty acid profiles using gas-liquid chromatography (GLC) and high-performance liquid chromatography (HPLC).
• Utilisation of silver nitrate thin-layer chromatography (TLC) for detailed characterization of unsaturated C18 fatty acids, including trans isomers.

Main Results:

• All analyzed human milk samples contained trans isomers of C18:1 fatty acids, with a mean level of 1.9% ± 0.2% of total fatty acids.
• Trans vaccenic acid was identified as the predominant trans C18:1 isomer.
• Various trans isomers of linoleic and alpha-linolenic acids were detected at lower concentrations, similar to those found in processed oils.

Conclusions:

• Human milk samples from French women contain detectable levels of trans fatty acids, including isomers of essential fatty acids.
• The presence of these trans fatty acids in human milk necessitates consideration for the newborn's dietary intake.
• Maternal dietary habits, such as consumption of deep-fried foods, may influence the trans fatty acid profile in human milk.