Key findings:
The FlaxPAD study revealed powerful hypotensive effects of milled flaxseed in patents with peripheral arterial disease and uncontrolled hypertension. The reasons are not known and could be due to any one of the compounds in flax (ALA, lignans, fiber, peptides), or a synergistic action of all 4 components together. This paper describes the design of the next study – the HYPERFLAX trial – which will further explore the blood pressure lowering effects of flax. In particular, the research is aimed to determine if participants newly diagnosed with stage 1 hypertension who are not taking anti-hypertensive medication will benefit from flaxseed consumption. It is anticipated that the results will provide further support for the use of flaxseed either as an alternative or an adjunct to medication for the treatment of high blood pressure.
ABSTRACT:
BACKGROUND: In 2013 the World Health Organization deemed hypertension as a global crisis as it is the leading risk factor attributed to global mortality. Therefore, there is a great need for effective alternative treatment strategies to combat a condition that affects 40% of adults worldwide. Recently, the FlaxPAD Trial observed a significant reduction in systolic and diastolic blood pressure in hypertensive patients with peripheral arterial disease that consumed 30 g of milled flaxseed per day for one year. However, these patients were already on anti-hypertensive medication. Therefore, there is a need to assess if dietary flaxseed can effectively reduce blood pressure in the absence of peripheral arterial disease and anti-hypertensive medication in newly diagnosed hypertensive patients. METHODS/DESIGN: The HYPERFlax Trial is a parallel, superiority, phase II/III, randomized, double-blinded, controlled clinical trial. St. Boniface Hospital and the Health Sciences Centre of Winnipeg, Canada, will recruit 100 participants newly diagnosed with stage 1 hypertension who have yet to be administered anti-hypertensive medication. Participants will be randomly allocated with a 1:1 ratio into a flaxseed or control group and provided food products to consume daily for six months. At baseline, two, four, and six months, participant assessments will include the primary outcome measure, averaged automated blood pressure, and secondary measures: 24-hour food recall, international physical activity questionnaire, anthropometrics, and blood and urine sampling for biochemical analysis. Plasma will be assessed for lipids, metabolomics profiling, and molecules that regulate vascular tone. Urine will be collected for metabolomics profiling. With an estimated dropout rate of 20%, the trial will have a power of 0.80 to detect differences between groups and across time, out of an effect size of 0.7 (SD) at an α level of 0.05. DISCUSSION: This trial will determine if dietary flaxseed is efficacious over six months as an anti-hypertensive therapy in subjects newly diagnosed with hypertension. If flaxseed can effectively reduce blood pressure as a monotherapy, then flaxseed will provide individuals on a global basis with a cost-effective food-based strategy to control hypertension. (Authors Abstract)