Therapeutic Benefits from Flaxseed
The consumption of flaxseed (Linum usitatissimum), or linseed which others call it, has become more common recently and has gained quite the traction of followers. You can easily find flaxseed recipes online for many different things varying from muffins to smoothies. Flaxseed is a mucilaginous and oily plant that comes from the Linaceae family. It is a great addition to the daily diet because it is high in omega-3 fatty acids. (Tilgner, 2009, p.80) Which in turn, can respectively provide therapeutic properties.
In a clinical trial titled Dietary Flaxseed Reduces Central Aortic Blood Pressure Without Cardiac Involvement but Through Changes in Plasma Oxylipins, researchers established that “dietary flaxseed generated a powerful reduction in brachial systolic and diastolic blood pressure in patients with peripheral artery disease.” (Caligiuri SP, et al., 2016) This clinical trial was a yearlong and was coined the FlaxPAD clinical trial. The researchers’ main objective was to determine the effect that flaxseed had on the central aortic blood pressure since studies had already been performed for brachial blood pressure. The clinical trial included 110 patients with a diagnosis of peripheral artery disease and their average age was 67 years old. Most of the patients chosen were already “on one or more various medications in order to lower blood sugar, lipids, blood pressure, or thrombotic complications.” (Caligiuri SP, et al., 2016) The experiment was quite simple really. The chosen patients were given a variety of different foods which included bagels, muffins, snack bars, buns, pasta, and tea biscuits. For one year, each patient would choose one of these foods and consume them. What the patients didn’t know, is that their food of choice for the day either contained 30 g of milled flaxseed or a placebo. During this clinical study, the number of patients lowered from 110 down to only 62 due to participants’ attrition and/or not meeting the quality criteria for the analyses. The participants blood pressure was measured using radial applanation tonometry and the SphygomoCor PWV Medical Software. Blood samples were taken from the participants at the beginning of the study and at the halfway mark of six months. These samples were used for assessment of oxylipins using high-performance liquid chromatography mass spectrometry. (Caligiuri SP, et al., 2016) Concluding the clinical trial, the researchers had found that the central systolic blood pressure had decreased in the flaxseed group by 3.4 and 4.9 mm Hg at the six-month point and twelve-month point from baseline. The placebo group also had lowered central systolic blood pressure, but the decrease was only at 1.7 and 3.3 mm Hg at the six month and twelve month points from baseline. In addition, the placebo group actually experienced an increase in the central diastolic blood pressure of 1.1 and 1.5 mm Hg from baseline. Of the blood plasma studied, researchers found 40 oxylipins that were identified. Out of these 40, nineteen of them were found to be higher in the participants with elevated cBP (over 130/80 mm Hg). The oxylipin trihydroxyoctadecenoic acid, plasma maresin, and 13-OxoDE were the only ones which were found to be lower in the participants with elevated cBP. (Caligiuri SP, et al., 2016) The data collected from the blood samples showed the researchers that it is “the involvement of ALA and oxylipins in the antihypertensive action of flaxseed.” (Caligiuri SP, et al., 2016) This is quite interesting information and seemed to be a well done study. The study states that most of the participants were on medications so I do wonder how the intake of medications effected the results of the study. Or how the results would be different if the participants were not on any medications. I appreciate how this study was an addition to other studies that covered flaxseed and hypertension, but, this one targeted central aortic blood pressure without the cardiac involvement. Also, this was a study done on humans to support the findings they found during animal studies.
The second study I would like to review regarding flaxseed is titled “Flaxseed modulates inflammatory and oxidative stress biomarkers in cystic fibrosis: a pilot study” conducted at the University of Pennsylvania and was published May 13, 2015 on PubMed. Cystic fibrosis, as defined by the Cystic Fibrosis Foundation, is a genetic disease that progressively causes lung infections and limits the individual’s ability to breathe. The lungs, pancreas, and other organs involved have a thick buildup of mucus which can clog the airways, and prevent the release of necessary digestive enzymes to break down the food that is consumed and to absorb nutrients. Currently, there is no cure for this disease despite the tremendous progress in treatments. (CF Foundation, n.d.) The reason for this study was to research how flaxseed could contribute in lowering inflammation in patients with cystic fibrosis and to test the effects on oxidative stress. This is due to the flaxseed containing high fiber, lignin phenolics, and omega-3 fatty acids which are naturally anti-inflammatory and antioxidant. (Turowski JB, et al., 2015) The methodology of this study included ten patients with a diagnosis of cystic fibrosis and five healthy individuals which were all volunteers. Individuals could not participate and were excluded from the study if they had “prior or planned hospitalization or surgical procedure within one month of enrollment, an acute pulmonary exacerbation, history of bowel resection, inflammatory bowel disease or distal intestinal obstruction syndrome, receiving broad spectrum intravenous or oral antibiotics (other than maintenance antibiotics) within one month of enrollment, current supplementation with flaxseed or soy derivatives or allergies to them, active or prior ingestion of Vitamin E exceeding 30 IU within 21 days, significant liver disease, significant renal dysfunction, or poorly controlled diabetes.” (Turowski JB, et al., 2015) Each individual consumed 40g of flaxseed each day for a total of four weeks. Weekly tests included urine tests for systemic oxidative stress, plasma for cytokine levels and flaxseed metabolites, and buccal swabs for gene expression of Nrf2-regulated antioxidant enzymes. All participants in this study completed it fully and none of them had any serious adverse effects from consuming the daily amount of flaxseed provided. The only complaint researchers received from the participants was a change in their bowel habits which ranged from mild abdominal discomfort to experiencing occasional diarrhea and constipation. These side effects were self-limited to the beginning of this study. One participant, one month after discontinuing flaxseed, experienced a flare up and had a new onset of connective tissue disease. Due to timing, it was not deemed “not directly secondary to FS ingestion.” (Turowski JB, et al., 2015) This study was quite limited when it came to their conclusions, but they do state that they are actively planning larger trials in order to further study these findings. The study did show the researchers that the addition of flaxseed to the dietary intake of a patient with cystic fibrosis was tolerated and safe though. I see this study as a positive step in the right direction, a stepping stone if you will, to further treatment research for cystic fibrosis. I think the study could have been improved by having a larger participant pool of volunteers and for the study time to be increased from only four weeks to at least a year long so they can assess the improvements better.
Caligiuri SP, et al. (2016, October). Dietary Flaxseed Reduces Central Aortic Blood Pressure Without Cardiac Involvement but Through Changes in Plasma Oxylipins. - PubMed - NCBI. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/27528063
CF Foundation. (n.d.). About Cystic Fibrosis | CF Foundation. Retrieved from https://www.cff.org/What-is-CF/About-Cystic-Fibrosis/
Tilgner, S. M. (2009). Materia Medica. In Herbal medicine from the heart of the earth (p. 88). Pleasant Hill, OR: Wise Acres LLC.
Turowski JB, et al. (2015, May 13). Flaxseed modulates inflammatory and oxidative stress biomarkers in cystic fibrosis: a pilot study. - PubMed - NCBI. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/25963404