Medical Attributes of Linum usitatissimum - Flaxseed
By Sarah Witkowski and Khushbu Desai
Wilkes University, Wilkes-Barre, PA
Flaxseed or linseed is obtained from the flax plant, Linum usitatissimum, which belongs
to the Linaceae or Flax family (Dodds et al. 2006). L. usitatissimum is an erect annual
plant with slender stems, alternate leaves, and flowers having five
blue petals (Wikipedia contributors 2007). This species grows in
Belgium, Britain, China, Egypt, Germany, India, Iraq, Kurdistan,
Mexico, Peru, Spain, Turkey, Venezuela, and the United States (Plants
For a Future 2000).
Flaxseed was originally used by Egyptians in foods and medicines. Also,
they cultivated flax to obtain linen (American Cancer Society 2007).
Later, flaxseed was mentioned by Hippocrates in his writings as an
abdominal pain reliever (Klimaszewski, 2000). Native Americans also
used flax as a cough and cold remedy (Moerman, 2007). Plants that are
rich in fiber, such as flax, have been commonly used as a laxative and
a regular dietary supplement for its health advantages (Giacco et al.
Many of the medicinal qualities of flaxseed are attributed to the high
concentrations of lipid alpha-linolenic acid (LNA), an omega-3 fatty
acid (Harper et al. 2006). Omega-3 fatty acids are not produced by the
human body and need to be gained from dietary sources (Logan, 2004).
LNA is a simple fatty acid that is converted into other fatty acids
that are proven to support cardiac health (Harper et al. 2006). The
body uses these simple fatty acids as a template to produce necessary
and more complex molecules. When combined with a low fat diet, LNA and
other fatty acids can reduce the effects of high cholesterol and lessen
the occurrence of non-fatal coronary infarctions (Dodin et al. 2005).
Cholesterolemia, or the presence of elevated LDL cholesterol, the bad
form of cholesterol which is responsible for heart disease and other
health risks, in the blood has shown to be decreased by supplementation
with flax (Dodin et al. 2005). Flax is also a good source of
other omega 3-fatty acids, which among other qualities are natural
blood thinners and help prevent clotting. Flax is thus a valuable
supplement for good cardiac health.
Omega 3-fatty acids are also known to reduce the risk of prostate
cancer as found by Demark-Wahnefried et al. in 2001, in the study of
flaxseed supplementation and fat restriction. They conducted the study
on twenty five men, varying in age, with prostate cancer waiting for
prostatectomy. The results showed that flaxseed diet along with strict
fat restriction decreased the hormonal levels of testosterone,
androgen, and cholesterol, leading to decreased proliferation and
increased apoptotic cancer cell death (Demark-Wahnefried et al 2001).
Omega-3 and omega-6 fatty acids, obtained from flaxseed oil, have also
been associated with good mental health. These fatty acids are shown to
be required by a developing nervous system, in both fetal and
adolescent systems, and decrease the occurrence of mental depressive
disorders (Logan 2004). In patients suffering from depressed moods, low
levels of omega fatty acids were found in the blood (Logan 2004). Many
studies have shown a negative correlation between depression and a diet
supplemented with higher levels of omega fatty acids (Logan 2004).
Supplementation with flax has also been shown to increase the
metabolism of postmenopausal women (Brooks et al. 2004). This could
help decrease the effect of menopause and eliminate the needs for
hormone replacement therapy with costly drugs such as Premarin. Flax
has been found to be a good source for phytoestrogens, a group of
lignin, or highly aromatic compounds derived from the cell walls of
plants, that are metabolized in the body like estrogenic compounds or
serve as precursors to the hormones. Phytoestrogens interfere with
estrogen metabolism in postmenopausal women and retard the progression
of breast cancer and osteoporosis. Studies indicate that the fecal and
urinary excretion levels of phytoestrogenic lignin in postmenopausal
women taking flax are higher than those who do not (Kurzer et al.
1995). This indicates the supplementation with flax raises the body’s
levels of such compounds that are usually lowered following menopause.
Flaxseed’s lignin, secoisolariciresinol diglycoside, was tested for its
ability to reduce tumor growth in postmenopausal breast cancer
patients. After days of flaxseed diet, women showed an increase in
urinary lignin which caused reduced expression of c-erbB2, usually
found in aggressive breast cancers. The study concluded that flaxseed
changes the phenotype of the cancer cells to a less aggressive form and
thus delays the progression of breast cancer (Thompson et al. 2005).
Flax is high in fiber, both insoluble fiber to support fecal binding
and soluble fiber to promote digestive motility (Demark-Wahnefried
2001). Foods high in fiber have also been known to slow the body’s
absorption of sugar into the blood stream. This allows the body to
better regulate blood sugar levels and insulin secretions, leading to a
decrease in hypoglycemia (Giacco et al. 2000). Because Flax is a good
source of fiber, flax supplementation may help those who are
hypoglycemic, diabetic, and those with insulin intolerance a way to
better control their blood glucose and insulin levels. The addition of
fiber to one’s diet is also thought to lower blood pressure and
cholesterol (Giacco et al. 2000).When incorporated into a diet, flax
can increase the amount of fiber and beneficial dietary lipids (Dodin
et al. 2005).
For its number of medicinal uses, flaxseed has achieved recognition in
complementary and alternative medicine for ages. More recently, the
National Center for Complementary and Alternative Medicine is
funding additional studies to evaluate or discover other medicinal
values of flaxseed (NCCAM 2006). Flax, like many herbal supplements,
does not have its origins in traditional Westernized medicine. However,
it is now gaining more scientific and medical evidence to verify its
American Cancer Society. 2007. Flaxseed. http://www.cancer.org/. Accessed
July 08, 2007.
Brooks JD, W.E. Ward, J.E. Lewis, J. Hilditch, L. Nickell, E.
Wong, and L.U. Thompson. 2004. Supplementation with flaxseed alters
estrogen metabolism in postmenopausal women to a greater extent than
does supplementation with an equal amount of soy. The American Journal of Clinical Nutrition
Demark-Wahnefried W, D.T. Price, T.J. Polascik, C.N. Robertson, E.E.
Anderson, D.F. Paulson, P.J. Walther, M. Gannon, and R.T. Vollmer.
2001. Pilot study of dietary fat restriction and flaxseed
supplementation in men with prostate cancer before surgery: Exploring
the effects on hormonal levels, prostate-specific antigen, and
histopathologic features. Urology
Dodds, P.N., G.J. Lawrence, A.M. Catanzariti, T. Teh, C.I.A. Wang, M.
Ayliffe, B. Kobe, and J.G. Ellis. 2006. Direct protein interaction
underlies gene-for-gene specificity and coevolution of the flax
resistance genes and flax rust avirulence genes. Proceedings of the National Academy of
Sciences of the United States of America 103(23): 8888-8893.
Dodin, S, A. Lemay, H. Jacques, F. Legare, J.C. Forest, and B. Masse.
2005. The effects of flaxseed dietary supplement on lipid profile, bone
mineral density, and symptoms in menopausal women: A randomized,
double-blind, wheat germ placebo-controlled clinical trial. The Journal of Clinical Endocrinolgy and
Metabolism 90 (3): 1390-1397.
Giacco, R., A. Gaicco, M. Parillo, L. D’Episocopo, A. Riverllese, G.
Riccardi, and G. Lasorella. 2000. Long term dietary treatments
with increased amounts of fiber-rich low-glycemic index natural foods
improves blood glucose control and reduces the number of hypoglycemic
events in Type I diabetic patients. Diabetes
Care 23: 1461-1466.
Harper, C.R., M.J. Edwards, A.P. DeFilipis, and T.A. Jacobson. 2006.
Flaxseed oil increases the plasma concentrations of cardioprotective
(n-3) fatty acids in humans. The Journal of Nutrition 136: 83-87.
Kurzer, M.S., J.W. Lampe, M.C. Martini, and H. Adlercreutz. 1995. Fecal
lignan and isoflavonoid excretion in premenopausal women consuming
flaxseed powder. Cancer
Epidemiology, Biomarkers, and Prevention 4: 353-358.
Klimaszewski, A. 2000. Flax for Health. http://www.fatsforhealth.com.
Accessed July 01, 2007.
Logan, A.C. 2004. Omega-3-fatty acids and major depression: A primer
for the mental health professional. Lipids
in Health and Disease 3: 25.
Moerman, D. American Indian uses for flax. University of
Accessed June 20, 2007.
National Center for Complementary and Alternative Medicine. 2006.
Herbs at a Glance. http://nccam.nih.gov/.
Accessed July 01, 2007.
Plants for a Future. 2000. Linum
Accessed July 08, 2007.
Thompson, L.U., J.M. Chen, T. Li, K. Strasser-Weippl, and P.E. Goss.
2005. Dietary flaxseed alters tumor biological markers in
postmenopausal breast cancer. Clinical Cancer Research 11(10): 3828.
Wikipedia contributors. 2007. Flax. Wikipedia, The Free
Accessed 17 July 2007.
This paper was developed as part of the BIO 368 - Medical Botany
course offered at Wilkes University during the summer of 2007. Course
instructor was Kenneth M. Klemow, Ph.D.
The information contained herein is based on published sources, and
is made available for academic purposes only. No warrantees,
expressed or implied, are made about the medical usefulness or
dangers associated with the plant species in question.
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This page posted and maintained by Kenneth M.
Klemow, Ph.D., Biology Department,
Wilkes University, Wilkes-Barre,
PA 18766. (570) 408-4758,