The membrane is the clear film lining the eggshell, visible when one peels a boiled egg. Eggshell membrane is primarily composed of fibrous proteins such as collagen type I. However, eggshell membranes have also been shown to contain glycosaminoglycans, such as dermatan sulfate and chondroitin sulfate and sulfated glycoproteins including hexosamines, such as glucosamine. Other components identified in eggshell membranes are hyaluronic acid, sialic acid, desmosine and isodesmosine, ovotransferrin, lysyl oxidase, lysozyme, and β-N-acetylglucosaminidase.
Eggshell membrane is commercially derived from the eggshells of industrial egg processors. In the United States, egg-breaking facilities generate more than 24 billion eggshells every year. There are various ways in which the membrane of an eggshell is separated from the shell, including chemical, mechanical, steam and vacuum processes: see Eggshell and protein membrane separation. The isolated membrane is then partially hydrolyzed and dried to produce a powder, distributed as eggshell membrane (EM).
Between November 2003 and February 2004, two open-label clinical studies in Missouri assembled 39 patients with various joint and connective tissue disorders, to measure the effect of doses of EM after 7 and 30 days. 34 patients completed the study, and utilizing a 0 to 10 analog Likert scale, reported increased flexibility, and decreased general and range of motion-associated pain. Subsequently, between December 2004 and January 2006, at three clinical sites in Missouri, 67 patients suffering moderate osteoarthritis of the knee were divided into two groups. One group was administered a placebo and the other received 500 mg of EM per day. Both the clinicians and the patients were blinded as to whether they were part of the placebo group or the EM group (a double-blind trial). Measurements were taken at 10, 30 and 60 days, using the WOMAC Index, which is a self-administered questionnaire addressing pain, stiffness and function or disability. Only 57% of the enrolled subjects completed the study, which was lower than anticipated. The treated group reported up to 26.6% improvement over placebo for pain and stiffness with no significant improvement in function and overall WOMAC.
Although this study is not a very strong result, suffering from a small group size and a very high non-completion rate as well as showing an unexpectedly small effect, this study has resulted in significant growth in the promotion and sale of egg membrane dietary supplements.
Since the publication of the clinical studies, eggshell membrane has surfaced in popular health culture as possible joint care, and in 2014 it was named in Alternative Medicine Magazine's Supplement Trend Watch.
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- Ruff, Kevin J.; DeVore, Dale P.; Leu, Michael D.; Robinson, Mark A. (2009). "Eggshell membrane: A possible new natural therapeutic". Clinical Interventions in Aging 4: 235–240. doi:10.2147/cia.s5797. PMC 2697588. PMID 19554094.
- "ESM History". ESM Technologies. Retrieved 13 June 2014.
- Ruff, Kevin J.; DeVore, Dale P.; Leu, Michael D.; Robinson, Mark A. (2009). "Eggshell membrane: A possible new natural therapeutic for joint and connective tissue disorders. Results from two open-label human clinical studies". Clinical Interventions in Aging 4: 235–240. doi:10.2147/cia.s5797. PMC 2697588. PMID 19554094.
- "WOMAC Osteoarthritis Index". WOMAC. Retrieved 13 June 2014.
- Ruff, Kevin J.; Winkler, Anne; Jackson, Robert W.; DeVore, Dale P.; Ritz, Barry W. (Aug 2009). "Eggshell membrane in the treatment of pain and stiffness from osteoarthritis of the knee: a randomized, multicenter, double-blind, placebo-controlled clinical study". Clinical Rheumatology 28 (8): 907–914. doi:10.1007/s10067-009-1173-4. PMC 2711914. PMID 19340512.
- Krahn, Bruce (Feb 2013). "Natural Eggshell Membrane: Treating chronic pain naturally". Alive Natural Health and Wellness (Feb 2013). Retrieved 13 June 2014.
- Berardi, John M. "Eggshell Membrane Reduces Joint Pain". Precision Nutrition. Retrieved 13 June 2014.
- Lynn, Lisa (April 2014). "Supplement Trend Watch". Alternative Medicine. Retrieved 13 June 2014.