The common antioxidants in food are vitamins C and E, carotenoids, flavonoids, and minerals such as selenium and manganese. Thousands of different molecules act as antioxidants that can donate an electron, including glutathione, Coenzyme Q, flavonoids, phenols, and polyphenols. A major misperception is that antioxidants are interchangeable. They are not. Each works differently in a specific situation. If all this sounds very complex, it is. Even the word antioxidant is somewhat misleading. It sounds like a single cure-all, and it is not.
The FDA developed an assay to assess the overall antioxidant activity in various foods to account for the wide variety of molecules and their interactions. (USDA 2007) This was called the Oxygen Radical Absorbance Capacity (ORAC). It was widely used until withdrawn in 2012 since there was no evidence of biological significance. However, many investigators still measure antioxidant activity with various assays in vitro and use this to suggest that it might be helpful in human health. This is known as hope-based science, not evidence-based science. Many food manufacturers still put an ORAC number on their products since they know that you don’t know it’s meaningless. It’s almost as silly as the claims—‘purity or concentration validated by an independent laboratory.’
The two best-known antioxidants in mushrooms are glutathione and ergothioneine. But here are some problems. The way the mushrooms are cooked can affect the amount. Frying and boiling reduce the content, while grilling appears to maintain their activity. However, there is little scientific evidence that they get into our cells or provide any benefit. Polyphenols are even more problematic as they break down and are rapidly excreted. Most publications use the phrase ‘potential’ benefit but provide no clinical evidence of efficacy. Many confuse correlation with causation merely by suggesting that low levels in older people cause aging or diminished cognition. A recent study of ergothioneine and cognitive decline has not published results (cliniclatrials.gov). It is telling when a study is listed as Closed, Status unknown. Much more work is required before we understand the possible value of any of these antioxidants.
There is evidence that ROSs are important during exercise, and the one thing you don’t want to do is remove them. It has also been suggested by scientists such as Nobel Laureate James Watson that ROSs are important during cancer chemotherapy and that antioxidants could decrease the effectiveness of treatment. Antioxidants may even increase the development of certain tumors, including the lung and prostate.
Bottom line. The extra antioxidants you eat will probably not harm you. They won’t help either. They do benefit two groups. If you listen carefully when you pay for your supplement or super-food, you will hear a marketing executive whisper ‘Gotcha’ and a nutraceutical CEO say ‘sucker.’ A decent diet, including a wide variety of foods, is usually all one needs. Good genes, laughter, luck, a strong social network, walking a few miles daily, clean air, and water are all more effective than a pill, a few mushrooms, or a glass of pomegranate juice. Or you can move to the island of Icaria in Greece, where people, on average, live a decade longer. We don’t know why.
Note: This article was first published in Fungi Magazine, which I highly recommend to all those interested in mushrooms. (https://www.fungimag.com/subscribe.htm) It is also part of a chapter in my upcoming book, Mushroom Mania: Facts and Fiction—Hope or Hype.
References
1. Behrendt I., G. Eichner and M. Fasshauer. 2020 Association of Antioxidants Use with All-Cause and Cause-Specific Mortality: A Prospective Study of the UK Biobank. Antioxidants (Basel). 16;9(12):1287. doi: 10.3390/antiox9121287. PMID: 33339307; PMCID: PMC7766648.
2. Bjelakovic G., D.Nikolova, L.L.Gluud, R.G.Simonetti and C Gluud. 2007. Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis. Journal of the American Medical Association 28;297(8):842-57
3. Bjelakovic G., D.Nikolova, L.L.Gluud, R.G.Simonetti and C.Gluud 2021 Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Cochrane database of systematic reviews.
4. Cheah I.K. and B.Halliwell 2021 Ergothioneine, recent developments. Redox Biology. Jun;42:101868. doi: 10.1016/j.redox.2021.101868. Epub 2021 Jan 26. PMID: 33558182; PMCID: PMC8113028.
5. https://clinicaltrials.gov/study/NCT03641404
Investigating the Efficacy of Ergothioneine to Delay Cognitive Decline (Current status unknown) Sponsor National University Hospital, Singapore. Last Update Posted 2018-08-22
6. Harvard TH Chan School of Public Health The Nutrition Source www.hsph.harvard.edu/nutritionsource/antioxidants/
7. Hekimi S., J. Lapointe, Y. and Wen. 2011 Taking a “good” look at free radicals in the aging process. Trends in Cell Biology. 21(10):569-76. doi: 10.1016/j.tcb.2011.06.008. Epub 2011 Aug 6. PMID: 21824781; PMCID: PMC4074523.
8. Moyer M. W. 2015 Think twice about taking antioxidants. Scientific American April 2015 https://www.scientificamerican.com/article/think-twice-about-taking-antioxidants/
9. Scientific American Oct 7 2015 Antioxidants may make cancer worse.https://www.scientificamerican.com/article/antioxidants-may-make-cancer-worse/
10. Schumacker P.T. 2006 “Reactive oxygen species in cancer cells: live by the sword, die by the sword”. Cancer Cell. 10 (3): 175–176. doi:10.1016/j.ccr.2006.08.015. PMID 16959608
11. Watson J. 2014 Oxidants, antioxidants and the current incurability of metastatic cancers. Open Biology 8;3(1):120144. doi: 10.1098/rsob.120144. PMID: 23303309; PMCID: PMC3603456.
12. WebMD. https://www.webmd.com/vitamins/ai/ingredientmono-1183/ergothioneine 13. USDA 2007 Oxygen Radical Absorbance Capacity (ORAC) of Selected Foodshttps://www.govinfo.gov/content/pkg/GOVPUB-A77-PURL-LPS106748/pdf/GOVPUB-A77-PURL-LPS106748.pdf