Most often known as sprouts on a deli sandwich or a large bale of dried plant clippings to be used as food for livestock, alfalfa is increasingly being studied for a wide range of uses in human alternative therapies. Medicago sativa (alfalfa) leaves contain high concentrations of flavonoids and other phenols. These compounds exert potent antioxidant actions as free radical scavengers and inhibitors of nitric oxide release.1 The list of proposed medicinal uses of alfalfa range from the treatment of arthritis to upset stomach.

Background

Alfalfa is a perennial flowering plant and a member of the pea family.1 In its peak growing season, the slender branching stems reach a height of 3 feet with tiny green leaves and small violet flowers.1 In early literature, the Greek herbalist Dioscorides wrote about the nutritional use of alfalfa in the first century AD.2 Our common name for alfalfa is a derivation of the Arabic term meaning ‘father of all foods,’ due to its high concentration of protein and vitamins.3 Alfalfa is thought to have originated in South and Central Asia but now grows in many zones around the world.4 It has been documented in Turkish writings around 1300 BC, Persian ruins from more than 6,000 years ago, and extensively in Chinese medicine.5 

Science 

Reports of numerous in vivo and small animal studies exploring the benefits of alfalfa. One laboratory study of rats fed diets high in fat found that alfalfa supplementation resulted in greater excretion of cholesterol and bile acids.6 The experimental group of rats excreted significantly more cholesterol and bile acids in their feces than the control group.6 The mechanism of this action was believed to be related to the way in which alfalfa affects the gastric absorption and hepatic storage of cholesterol.6,7 

Another area of research that involves alfalfa is in the development of neuroprotective agents. One laboratory study using mice found reduced initial cerebral infarction size with alfalfa pre-treatment.8 Cerebral infarctions were induced in both the control and treatment groups.8 The test group was pre-treated with an extract of Medicago sativa. The mouse brains were then evaluated for size of infarction as well as response to reperfusion and the post-infarction release of specific pathogenic oxidative substances. The mice that were pre-treated with alfalfa extract showed not only reduced initial infarction size but also greater recovery after reperfusion.8

Other literature suggests a possible use for alfalfa in reducing serum glucose in diabetic subjects. One of the mechanisms involved in diabetes and elevated glucose is the decrease in cellular uptake of serum glucose. This defect in metabolism appears to involve free-radical-mediated pathology. In a review of the chemical and pharmacologic uses of alfalfa, researchers claimed that there was no significant impact of alfalfa on serum glucose levels.9 Another study of human red cells from healthy volunteers showed a small but statistically insignificant decrease in the glycosylation of hemoglobin.10 This information suggests alfalfa might be of some use as adjunctive therapy in patients considered ‘pre-diabetic.’ 

Safety, interactions, side effects

Despite the wealth of valuable nutrients and metabolic compounds, there is still substantial concern about the safety of alfalfa use.11 Long-term use of alfalfa, especially the seeds, has an immune-stimulating effect and can worsen autoimmune conditions such as lupus and multiple sclerosis. Weak estrogenic effects make use of alfalfa in patients with risks for breast or uterine cancer inadvisable. Safety has not been established for use in pregnant or nursing mothers or in infants. 

Alfalfa contains a high concentration of vitamin K, so patients currently taking any anticoagulant medication should seek their healthcare provider’s input before taking any alfalfa product. Also, with the known mild hypoglycemic effect, patients already taking medication for diabetes should be cautioned regarding the potential for unintentional drops in blood glucose. 

How supplied, dose, cost 

For those without contraindications who wish to use alfalfa as a supplement, a typical recommended dose is 5 to 10 grams steeped as a tea and used three times daily.11 Alfalfa can be found in many forms from seeds and fresh sprouts to dried leaves and powder. Alfalfa tea is a popular form of the plant. Dried leaves for tea cost from $10 to $15 per pound. 

Summary

Although alfalfa does have great potential for a wide variety of conditions, there are safer, better studied herbal supplements that are widely available. Until such time as more human trials showing safety and efficacy are conducted, healthcare providers should not recommend use of this supplement. However, the occasional deli sandwich with alfalfa sprouts should not cause harm.

References

  1. Karimi E, Oskoueian E, Oskoueian A, Omidvar V, Hendra R, Nazeran H. Insight into the functional and medicinal properties of Medicago sativa (alfalfa) leaves extract. Journal of Medicinal Plants Research. 2013;7:290-297.
  2. Petrovska BB. Historical review of medicinal plants’ usage. Pharmacogn Rev. 2012;6:1-5.
  3. Alfalfa. Health One: Advanced Internal Medicine Physician Care website. http://advancedimdenver.com/hl/?/21465/Alfalfa. Updated December 15, 2015. Accessed April 12, 2017.
  4. Jones T. Alfalfa. https://authoritynutrition.com/alfalfa. Accessed April 12, 2017.
  5. Group E. Benefits of alfalfa leaf. http://www.globalhealingcenter.com/natural-health/benefits-of-alfalfa-leaf. Published March 22, 2013. Updated November 24, 2015. Accessed April 12, 2017.
  6. Yuan D, Shi Y, Wan C, Guo R, Wang J. Effect of alfalfa saponins on cholesterol metabolism and its molecular mechanisms. 2013. Acta Practaculturae Sinica.
  7. Shi Y, Guo R, Wang X, et al. The regulation of alfalfa saponin extract on key genes involved in hepatic cholesterol metabolism in hyperlipidemic rats. PLoS ONE. 2014;9:e88282.
  8. Bora KS, Sharma A. Evaluation of antioxidant and cerebroprotective effect of Medicago sativa Linn. against ischemia and reperfusion insult. Evid Based Complement Alternat Med. 2011;2011:792167.
  9. Duggal J, Khatri P, Tiwari BN, Patel R. Chemo-pharmacological aspects of alfalfa: A review. J Adv Sci Res. 2011;2:50-53.
  10. Hosseini M, Asgary S, Najafi S. Inhibitory potential of pure isoflavonoids, red clover, and alfalfa extracts on hemoglobin glycosylation. ARYA Atheroscler. 2015;11:133-138.
  11. US National Library of Medicine. Alfalfa. https://medlineplus.gov/druginfo/natural/19.html. Reviewed February 12, 2015. Accessed April 12, 2017.