Supplementing lactating women with flaxseed oil does not increase docosahexaenoic acid in their milk

Am J Clin Nutr. 2003 Jan;77(1):226-33. doi: 10.1093/ajcn/77.1.226.


Background: Flaxseed oil is a rich source of 18:3n-3 (alpha-linolenic acid, or ALA), which is ultimately converted to 22:6n-3 (docosahexaenoic acid, or DHA), a fatty acid important for the development of the infant brain and retina.

Objective: The objective of this study was to determine the effect of flaxseed oil supplementation on the breast-milk, plasma, and erythrocyte contents of DHA and other n-3 fatty acids in lactating women.

Design: Seven women took 20 g flaxseed oil (10.7 g ALA) daily for 4 wk. Breast-milk and blood samples were collected weekly before, during, and after supplementation and were analyzed for fatty acid composition.

Results: Breast milk, plasma, and erythrocyte ALA increased significantly over time (P < 0.001) and after 2 and 4 wk of supplementation (P < 0.05). Over time, 20:5n-3 (eicosapentaenoic acid, or EPA) increased significantly in breast milk (P = 0.004) and in plasma (P < 0.001). In addition, plasma EPA increased significantly (P < 0.05) after 2 and 4 wk of supplementation. There were significant increases over time in breast-milk 22:5n-3 (docosapentaenoic acid, or DPA) (P < 0.02), plasma DPA (P < 0.001), and erythrocyte DPA (P < 0.01). No significant changes were observed in breast-milk, plasma, or erythrocyte DHA contents after flaxseed oil supplementation.

Conclusions: Dietary flaxseed oil increased the breast-milk, plasma, and erythrocyte contents of the n-3 fatty acids ALA, EPA, and DPA but had no effect on breast-milk, plasma, or erythrocyte DHA contents.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Diet
  • Docosahexaenoic Acids / analysis
  • Docosahexaenoic Acids / metabolism*
  • Fatty Acids / blood
  • Fatty Acids / metabolism*
  • Female
  • Humans
  • Lactation*
  • Linseed Oil / administration & dosage*
  • Linseed Oil / metabolism
  • Milk, Human / chemistry*


  • Fatty Acids
  • Docosahexaenoic Acids
  • Linseed Oil