Systematic Review and Meta-analysis of Flaxseed/Reply to Pierce et al

• Published in: The Journal of nutrition Vol. 145; no. 11; p. 22630
• Main Authors: Pierce, Grant N, Rodriguez-Leyva, Delfin, Caligiuri, Stephanie P B, Edel, Andrea L, Khalesi, Saman, Irwin, Christopher, Schubert, Matt
• Format: Journal Article
• Language: English
• Published: Bethesda American Institute of Nutrition 01.11.2015
• Subjects: Bioavailability; Blood pressure; Clinical trials; Flax; Handbooks; Health sciences; Hypertension; Meta-analysis; Metabolism; Metabolites; Quality control; Studies
• ISSN: 0022-3166

The subgroup analysis of hypertensive patients at baseline in the Flaxseed and Peripheral Arterial Disease randomized controlled trial revealed that flaxseed induced a 15.2-mm Hg decrease in SBP and a 6.7-mm Hg decrease in DBP (2). [...]the conclusion that "flaxseed may lower blood pressure slightly," as described in the Khalesi et al. review (1), may underestimate the antihypertensive effects shown by flaxseed in hypertensive patients included in a randomized controlled trial (2). Ground (milled) flaxseed added to the diet provides substantially more a-linolenic acid (4) and lignan metabolites (5) to the blood than does whole flaxseed. Because a-linolenic acid and lignans may be important bioactive compounds involved in the antihypertensive action of dietary flaxseed (2, 6), referring to the 2 forms as thesameisincorrect. [...]we have concerns about the quality of the data and the conclusions obtained from these data when combining very different interventions into the same meta-analysis.