Flaxseed Health Benefits
Flaxseed health benefits are associated with its high omega-3 fatty acid and lignin content, which make it helpful in the treatment of BPH and prostate cancer. Also known as linseed, flaxseed (Linum usitatissimum) is a product of the flax plant, an annual herb that is high in fiber and a substance called mucilage.
The combination of fiber and mucilage make flaxseed an effective laxative, a use for which it has been valued for millennia. But flaxseed health benefits don’t stop in the intestinal tract.
How Flaxseed Works
Flaxseed and flaxseed oil are also rich in an omega-3 fatty acid called alpha-linolenic acid (ALA). This essential fatty acid has demonstrated health benefits regarding prostate cancer, benign prostatic hyperplasia, heart disease, high cholesterol, inflammatory bowel disease, arthritis, and other health problems. However, not all the studies for each of these conditions have been positive. For treatment of high blood pressure and elevated blood sugar levels in diabetics, the evidence has been convincing. These flaxseed health benefits have been attributed to the plant’s high soluble fiber content. However, the findings have been mixed in the areas of prostate health and prostate cancer.
Flaxseed Health Benefits Studies
In a pilot study conducted at Duke University Medical Center, researchers explored the impact of a flaxseed-supplemented, low-fat diet on the proliferation rates in benign prostate epithelium. Fifteen men who were scheduled to undergo prostate biopsy were placed on a low-fat diet plus 30 grams of flaxseed daily for six months. Investigators observed a significant decrease in the benign epithelium, PSA, and cholesterol levels when compared with the baseline values. The authors suggested that a low-fat diet along with flaxseed may have a positive impact on controlling prostate growth. (Demark-Wahnefried 2004)
Flaxseed health benefits may extend to the fight against prostate cancer as well. Investigators evaluated the impact of flaxseed supplementation and/or a low-fat diet on 161 men with prostate cancer who were scheduled for prostatectomy. For an average of 30 days before surgery, the men participated in one of four groups: control (usual diet), flaxseed supplemented diet (30 g per day), low-fat diet, or a flaxseed-supplemented, low-fat diet. When the researchers examined the tumors removed from the men during prostatectomy, they found that prostate cancer growth was significantly lower in the men who had consumed flaxseed. (Demark-Wahnefried 2008)
According to lead author Wendy Demark-Wahnefried, the omega-3 fatty acids in flaxseed appear to change how cancer cells lump together or bind to other cells. In addition, the lignans (a phytonutrient/phytoestrogen) in flaxseed choke off the blood supply to the tumor, which helps stop cancer’s growth.
Other studies have challenged flaxseed health benefits claims regarding prostate health. In a large review of flaxseed in humans, experts from Memorial Sloan-Kettering Cancer Center identified 13 categories in which flaxseed had been studied, inclding prostate cancer. They concluded nearly all the studies had been of poor quality and that “although flaxseed and flaxseed oil have several promising future uses, the available literature does not support recommendation for any condition at this time.” (Basch 2007)
One of the reviewed studies reported on the association between the risk of prostate cancer and intake of the omega-3s—ALA, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA)—and the omega-6 fatty acids linoleic acid and arachidonic acid. A total of 47,866 men were followed for 14 years.
The investigators identified 2,965 new cases of total prostate cancer during the follow-up period. Of these, 448 cases were advanced. An analysis showed that intake of ALA was associated with an increased risk of advanced prostate cancer. In fact, ALA from nonanimal sources such as flaxseed and flaxseed oil provided a greater risk than ALA from meat and dairy sources. Intake of EPA and DHA was associated with a lower risk of both total and advanced prostate cancer. The omega-6 fatty acids were unrelated to prostate cancer risk. (Leitzmann 2004)
How To Take Flaxseed
To appreciate flaxseed health benefits, the suggested dose is 1 tablespoonful, 2 to 3 times daily, or 2 to 4 tablespoons once daily. (University of Maryland) The seeds should be ground before they are consumed, as this improves their digestibility, and you should take them with a full glass of water. Ground flaxseeds can also be added to foods, such as oatmeal, salads, and smoothies. Possible side effects of flaxseed (ground or whole) include gas heartburn, indigestion, and nausea. Flaxseed oil in large amounts may cause flatulence and loose stools.
Basch E et al. Flax and flaxseed oil (Linum usitatissimum): a review by the Natural Standard Research Collaboration. J Soc Integr Oncol 2007 Summer; 5(3): 92-105
Demark-Wahnefried W et al. Pilot study to explore effects of low-fat, flaxseed-supplemented diet on proliferation of benign prostatic epithelium and prostate-specific antigen. Urology 2004 May; 63(5): 900-4
Demark-Wahnefried W et al. Flaxseed supplementation (not dietary fat restriction) reduces prostate cancer proliferation rates in men presurgery. Cancer Epidemiol Biomarkers Prev 2008 Dec; 17(12): 3577-87
Leitzmann MF et al. Dietary intake of n-3 and n-6 fatty acids and the risk of prostate cancer. Am J Clin Nutr 2004 Jul; 80(1): 204-16
University of Maryland Medical Center: http://www.umm.edu/altmed/articles/flaxseed-000244.htm