A Lesser-Known Antioxidant Makes Mushrooms Important to Health

The real secret to their wide-ranging health benefits may be the lesser-known antioxidant ergothioneine (ergo). However, modern agricultural methods may be depriving us of enough ergo in our diet.

A Complex Mix of Nutrients

Medicinal mushrooms are a hot topic these days with species such as reishi, cordyceps, lion’s mane, chaga, and maitake studied for their health properties. They’ve even been labeled as “functional foods” with a wide variety of mushroom-containing supplements available to address specific health issues or provide therapeutic support.

The interest in mushrooms is well-founded. Over the hundreds of clinical studies completed to date, mushrooms have been shown to have anti-inflammatory, anti-viral, metabolic-regulating, immune-boosting, and cancer-fighting properties.

The vast array of bioactive compounds in mushrooms includes various vitamins and minerals, polyphenols, flavonoids, and amino acids. They are particularly high in beta-glucans—credited with most of mushrooms’ immune-boosting properties as well as their positive effects on metabolic health and anti-tumor activity. In terms of their antioxidant content, it is usually the glutathione that gets the most attention.

Glutathione is often referred to as the “master detoxifier” given its critical role in protecting cells from oxidative damage and the toxicity associated with chemicals and infectious agents. The role of glutathione in the body was highlighted during the COVID-19 pandemic when it was found that N-acetylcysteine, a precursor enabling the body to synthesize glutathione, was an effective preventive and treatment for COVID-19.

More recent research is highlighting how ergo may be a significant contributor to these effects.

Mushrooms’ Unique ‘Longevity Vitamin’

Mushrooms are unique in their biological construct as they do not use chlorophyll or photosynthesis like plants or ingest food like animals—rather, they “absorb” decaying matter. While this leads to a unique nutritional profile, most of the nutrients they contain can be found in other foods. However, according to a review published in Nutrition Research Reviews ergo is synthesized only by mushrooms and certain bacteria—not by plants, animals, or the human body.

While ergo was discovered decades ago, its importance was only realized in 2005 when a pivotal discovery was made that humans (and other mammals) have a specialized transporter protein for ergo. Dubbed the “ergo transporter,” it has been shown to be responsible for the rapid and efficient extraction of Ergo from food in the intestines into red blood cells which carry it all around the body.

Research published in an upcoming issue of Biochemical and Biophysical Research Communications found that ergo is taken up directly into our cellular mitochondria. Mitochondria are a cell’s powerhouse, creating all the energy we need for cellular function. Research has also found that ergo protects cells from disease and prevents mitochondrial damage.

Ames noted in a paper published in PNAS in 2018 that ergo “acts as an adaptive antioxidant for the protection of injured tissues,” and may play an important role in protecting cells against oxidative damage.

A Swedish study looking at cardiovascular disease in 3,236 individuals monitored more than 100 different metabolites to see if any could predict cardiac risks. Higher ergothioneine levels were found to be an independent marker for lower risk of cardiovascular disease and mortality.

These studies of ergo have also shown that it builds up gradually in the body and is excreted very slowly. This fact, together with the specialized transporter protein, implies it has an important physiological role even if the extent of its functions is not yet fully known.

While many studies have focused on the health effects of mushrooms in general, these newer studies, focus on the ergo—its action in the body and availability to cells.

The Link Between Soil and Human Health

The intrigue builds when you consider the role of fungi and bacteria in our soil. Healthy untouched soil is teeming with trillions of bacteria plus the mycelium of mushrooms and fungi. Mycelium is similar to a plant’s root system and consists of an interwoven mass of tiny hyphae (branching filaments) that absorb nutrients from the soil. They then pass nutrients to other parts of the colony through an intricate exchange with plant roots.

Studies have shown that ergo is found in a few plant foods, most notably tempeh which is a soybean product fermented with fungi. Smaller amounts are found in certain kinds of asparagus, depending on the conditions in which they are grown. Some beans and oats have measurable amounts. While these foods cannot synthesize ergo, they are able to take it up from the soil where it is produced by mushroom mycelium and many types of bacteria.

While there is a growing interest in regenerative agriculture emphasis tends to be on the sustainability of the soil and avoidance of chemical pesticides which are toxic to humans. While a noble endeavor, says Beelman, enhancing the levels of ergo needs to be added to the conversation.

Experiments focusing on tillage practices (plowing) used by industrial agriculture show that greater intensity of soil tilling leads to an associated reduction in fungi biomass and a reduction in ergo concentration in the crops grown. Beelman said he would like to see more research in this area as well as into the ergo concentrations in organic produce and the entire food supply.

Mushrooms are especially absorbent of any contaminants in the soil or air like pesticides. White button mushrooms are one of the lowest sources of ergo.

2. Choose Organic and Regeneratively Grown Foods

Regeneratively grown produce usually comes from small local farms with no tillage and natural methods rather than fertilizer and pesticide use. This means that the networks of fungal mycelium in the soil can stay intact and better convert decaying plant matter into important nutrients such as ergo. Organic and pasture-raised are also good options.

3. Supplements

As with any identified nutrient, commercial products are available. Make sure to research how the ergo is obtained and its measurable bioavailability in your body. Still, don’t give up on trying to eat mushrooms for all their other fantastic properties and health benefits.

Closing Thoughts

Ergothioneine, with its unique source and evidence of importance to human health, emphasizes the critical role mushrooms and bacteria have in this ecosystem we call nature and life. Man may be at the top of the food chain, but we cannot survive without the natural system that has been designed to support us. Our good health depends on embracing all aspects that Earth has provided to us.

How to Eat More Mushrooms

• Portobello mushrooms make a great alternative to a burger patty.
• Add some finely chopped shiitake or cremini mushrooms to your ground beef in just about any recipe.
• Add some protein powder featuring mushrooms into your smoothies.
• Try some magnificent oyster mushrooms from the local farmer’s market, sautéed in garlic and butter, and put on top of a grass-fed steak.
• Embark on a project to grow your own mushrooms at home. For safety, it’s best to start with a kit from a reputable company.