Consumption of unregulated food items (false morels) and risk for neurodegenerative disease (amyotrophic lateral sclerosis)

View or download the full article: 

P.S. Spencer


Oregon Health & Science University, Portland, Oregon, 97201, USA


Unknown environmental factors are thought to contribute to the etiology of sporadic forms of amyotrophic lateral sclerosis (ALS). Strong evidence supporting this view is found in the post-World War decline and disappearance of highincidence ALS in three Western Pacific populations that formerly utilized neurotoxic cycad seed as a traditional source of food and/or medicine. The principal toxins in cycads (cycasin) and in False Morel mushrooms (gyromitrin) generate methyl free radicals that damage DNA and cause mutation and uncontrolled division of cycling cells and degeneration of late-/postmitotic neurons. Since False Morels are scavenged for food in Finland, Russia, Spain, and USA, research studies are underway in Western Europe and USA to determine if the practice is associated with sporadic ALS.

amyotrophic lateral sclerosis, cycad seed, cycasin, gyromitrin, DNA damage, Guam, Finland, Russia, USA.
Spencer P.S. Consumption of unregulated food items (false morels) and risk for neurodegenerative disease (amyotrophic lateral sclerosis). Health Risk Analysis, 2020, no. 3, pp. 94–99. DOI: 10.21668/health.risk/2020.3.11.eng
  1. Al-Chalabi A., Hardiman O. The epidemiology of ALS: a conspiracy of genes, environment and time. Nat. Rev. Neurol., 2013, no. 9, pp. 617–628. DOI: 10.1038/nrneurol.2013.203
  2. Spencer P.S., Palmer V.S., Kisby G.E. Seeking environmental causes of neurodegenerative disease and envisioning primary prevention. Neurotoxicology, 2016, vol. 56, pp. 269–283. DOI: 10.1016/j.neuro.2016.03.017
  3. Plato C.C., Garruto R.M., Galasko D., Craig U.-K., Plato M., Gamst A., Torres J.M., Wiederholt W. Amyotrophic lateral sclerosis and parkinsonism-dementia complex of Guam: changing incidence rates during the past 60 years. Am. J. Epidemiol., 2003, vol. 157, pp. 149–157. DOI: 10.1093/aje/kwf175
  4. Román G.C. Neuroepidemiology of amyotrophic lateral sclerosis: clues to aetiology and pathogenesis. J. Neurol. Neurosurg. Psychiat., 1996, vol. 61, pp. 131–137. DOI: 10.1136/jnnp.61.2.131
  5. Spencer P.S., Gardner E., Palmer V.S., Kisby G.E. Environmental neurotoxins linked to a prototypical neurodegenerative disease. Environmental Factors in Neurodevelopment and Neurodegenerative Disorders. Elsevier Publ., 2015, pp. 212–237.
  6. Kisby G.E., Fry R.C., Lasarev M.R., Bammler T.K., Beyer R.P., Churchwell M., Doerge D.R., Meira L.B. [et al.]. The cycad genotoxin MAM modulates brain cellular pathways involved in neurodegenerative disease and cancer in a DNA damagelinked
    manner. PLoS One, no. 6, pp. e20911. DOI: 10.1371/journal.pone.0020911
  7. Gamberini M., Leite L.C. Carbon-centered free radical formation during the metabolism of hydrazine derivatives by neutrophils. Biochem Pharmacol, 1993, vol. 45, pp. 1913–1919. DOI: 10.1016/0006-2952(93)90451-2
  8. Spencer P.S. Hypothesis: Etiologic and molecular mechanistic leads for sporadic neurodegenerative diseases based on experience with Western Pacific ALS/PDC. Front Neurol, 2019, no. 10, pp. 754. DOI: 10.3389/fneur.2019.00754
  9. Toth B. Hepatocarcinogenesis by hydrazine mycotoxins of edible mushrooms. J. Tox. Env. Hlth., 1979, no. 5, pp. 193–202. DOI: 10.1080/15287397909529744
  10. Bergman K., Hellenäs K.E. Methylation of rat and mouse DNA by the mushroom poison gyromitrin and its metabolite monomethylhydrazine. Cancer Lett., 1992, vol. 61, pp. 165–170. DOI: 10.1016/0304-3835(92)90175-u
  11. Spencer P.S., Lagrange E., Camu W. ALS and environment: clues from spatial clustering? Rev. Neurol. (Paris), 2019, vol. 175, pp. 652–663. DOI: 10.1016/j.neurol.2019.04.007
  12. Gyromitra esculenta, a false morel. Mushroom Magicians. BioWeb, 2007. Available at: (03.04.2020).
  13. False morel (Gyromitra esculenta). Nordic Recipe Archive (Glossary), 2005. Available at: (03.04.2020).
  14. Härkönen M. Uses of mushrooms by Finns and Karelians. Int. J. Circumpolar Hlth, 1997, no. 57, pp. 40–55.
  15. Tom Volk's Fungus of the Month for May 2002. This month's fungus is Gyromitra esculenta, one of the false morels. University of Wisconsin. Plant Teaching Collection, 2002. Available at: (03.04.2020).
  16. On Cooking False Morels/Gyromitra. Foragerchef, 2020. Available at: (03.04.2020).
  17. Safe use of foodstuffs. Finnish Food Authority. Available at: (16.04.2020).
  18. Rautavaara T. Suomen Sienisato (Studies on the Mushroom Crop in Finland and its Utilization). Porvoo, Werner Söderström Osakeyhtiö Publ., 1947, pp. 534.
  19. Horowitz K.M., Horowitz B.Z. Gyromitra Mushroom Toxicity. StatPearls. Available at: (16.04.2020).
  20. Sabel C.E., Boyle P.J., Löytönen M., Gatrell A.C., Jokelainen M., Flowerdew R., Maasilta P. Spatial clustering of amyotrophic lateral sclerosis in Finland at place of birth and place of death. Am. J. Epidemiol., 2003, vol. 157, pp. 898–905. DOI: 10.1093/aje/kwg090
  21. Gyromitra esculenta – False morel. Mushrooms, 2019. Available at: (16.04.2020).
  22. Zaraf’iants G.N. Forensic medical diagnostics of intoxication with certain poisonous mushrooms in the case of the lethal outcome in a hospital. Sud. Med. Ekspert., 2016, vol. 59, pp. 22–28. DOI: 10.17116/sudmed201659122-28
  23. Verpa bohemica. Wikipedia. The Free encyclopedia, 2020. Available at: (16.04.2020).
  24. Skryabina A.A. Fructification of some species of edible fungi from the family Helvellaceae in the Slobodsky Roan of the Kirov Oblast. Rastitel'nye Resursy, 1975, no. 11, pp. 552–555.
  25. Orr D.B., Orr R.T. Mushrooms of Western North America. Berkeley, California, University of California Press Publ., 1979, 36 p.
  26. Popov E., Svetasheva T. 2019. Gyromitra korshinskii. The IUCN Red List of Threatened Species, 2019, pp. e.T75118940A75118943. DOI: 10.2305/IUCN.UK.2019-2.RLTS.T75118940A75118943.en
  27. Goss P.E., Strasser-Weippl K., Lee-Bychkovsky B.L., Fan L., Li J., Chavarri-Guerra Y., Liedke P.E.R., Pramesh C.S. [et al.]. Challenges to effective cancer control in China, India, and Russia. Lancet Oncol, 2014, no. 15, pp. 489–538. DOI: 10.1016/S1470-2045(14)70029-4
  28. Avksentyeva M. Colorectal cancer in Russia. Eur. J. Health. Econ., 2010, vol. 10, no. 1, pp. 91–98. DOI: 10.1007/s10198-009-0195-9
  29. Andersen P.M., Spitsyn V.A., Makarov S.V., Nilsson L., Kravchuk O.I., Bychkovskaya L.S., Marklund S.L. The geographical and ethnic distribution of the D90A CuZn-SOD mutation in the Russian Federation. Amyotroph Lateral Scler. Other. Motor. Neuron. Disord., 2001, no. 2, pp. 63–69. DOI: 10.1080/146608201316949406
  30. Lysogorskaia E.V., Abramycheva N.Y., Zakharova M.N., Stepanova M.S., Moroz A.A., Rossokhin A.V., Illarioshkin S.N. Genetic studies of Russian patients with amyotrophic lateral sclerosis. Amyotroph Lateral Scler Frontotemporal Degener, 2015, no. 17, pp. 135–141. DOI: 10.3109/21678421.2015.1107100
  31. Bunina T.L. On intracellular inclusions in familial amyotrophic lateral sclerosis. Korsakov J. Neuropathol. Psychiatry, 1962, vol. 62, pp. 1293–1299.
  32. Rowland L.P. T.L. Bunina, Asao Hirano, and the post-mortem cellular diagnosis of amyotrophic lateral sclerosis. Amyotroph Lat Scler, 2009, no. 10, pp. 74–78. DOI: 10.1080/17482960802382321

You are here