MUSHROOMS: NUTRITIONAL VALUE AND HEALTH BENEFITS

In this artical we will cover six scientifically validated reasons why you may want to consider eating more mushrooms! This will be a long artical so if you would like to skip the introduction, please scroll down to below the first image.

INTRODUCTION

Over the years of cultivating mushrooms, I’ve come to realize that mushrooms are really impressive. Not only do they impart flavour and texture to meals, but they can also influence our health in many positive ways.

Research shows that adding a few servings of mushrooms to our meals on a weekly basis can lead to significant health outcomes.

In this article, we won’t focus on medicinal mushrooms, even though many reported health benefits that are associated with fungi are linked to medicinal mushrooms like turkey tail, Reishi and cordyceps.

We also will not be focusing on hallucinogenic mushrooms, even though there’s ample research on the therapeutic benefits of compounds derived from these fungi. For more information on magic mushrooms please see one of our articles regarding this topic. Mental Health And Micro Dosing Magic Mushrooms – Set And Setting By Timothy Leary – Psilocybin Advances – Are Magic Mushrooms Legal In South Africa?

Instead, we will be focusing exclusively on the nutritional profiles and associated health benefits of edible mushrooms. We are going to do this by taking a look at the latest information published in the scientific literature.

Before we begin there are three things that I want to mention. First, no two mushrooms are alike, there are thousands of edible mushroom species, each one is undoubtedly unique from a nutritional standpoint. The nutritional composition of each mushroom may vary depending on the part people consume, the time of year they harvest it, the growing conditions, and the post-harvest treatment.

Second, no edible mushroom that I’m aware of is a magic bullet. Some mushrooms might be closer to magic bullet status than others, but no edible mushroom on its own can make up for a diet and poor lifestyle choices. We cannot neglect our health and expect two to three weekly servings of mushrooms to fix us. Although, a few servings of mushrooms a week in addition to quality sleep, quality relationships, proper hydration, movement practices, nightly journaling practices, a willingness to be of service to others and living with a sense of purpose can all make a difference over time.

Third, this article will not cover every single nutrient found within every single mushroom. The topic is obviously too vast, and the research is constantly being updated. So rather than offing you a comprehensive exposition on the subject, I will narrow down the list to six features that I think will be most relevant to you. 

All mushrooms contain Ergosterol in their cell membranes. The vitamin D2 content generated through sun exposure can vary significantly depending on length of sun exposure, time of day, weather, conditions and latitude. What this means is that you can manipulate this process at least to some degree. You can increase the amount of vitamin D2 in mushrooms by exposing them to the Sun or to UV lamps.

HOW TO INCREASE VITAMIN D2 IN MUSHROOMS

To generate the most vitamin D2 I recommend exposing your mushrooms with the gills or pores facing up toward the Sun and slicing your mushrooms thinly beforehand. The reason we’re doing this is to increase the surface area of our mushrooms. Increasing the surface area means more Ergosterol in the Sun, and more Sun treated Ergosterol means more vitamin D2. Now, how effective is this process?

There are many studies on this subject, including a study published in the Journal of nutrition and food sciences. Researchers discovered that treatment for as little as 15 minutes on a clear or partly cloudy day consistently increased vitamin D2 by at least 25% of the Dietary Reference intake per 70 gram serving. In many cases this was more than 100% of the Dietary Reference intake.

As a reference, health authorities currently set the recommended dietary allowance of vitamin D for most people at 600 international units. If we look a little more closely at this research, we see just how effective sun exposure can be in increasing the vitamin D2 content of 5 mushrooms in particular.

Mushrooms that were not exposed to sunlight provided less than 10% of the Dietary Reference Intake of vitamin D2. While all sun-exposed mushrooms had much greater levels of vitamin D2. With Shiitake mushrooms, Oysters mushrooms and Enoki mushrooms providing over 100% of the Dietary Reference intake of vitamin D2.

IS VITAMIN D2 FROM MUSHROOMS USEFUL FOR HUMANS?

Is vitamin D2 from mushrooms useful for humans? The answer is yes. A study published in the American Journal of Clinical Nutrition found that vitamin D2 in Chanterelle mushrooms increased vitamin D levels in humans as effectively as vitamin D2 supplements.

Another study found that adults who ingested vitamin D2 for mushrooms for 3 months were able to raise and maintain their body’s vitamin D status similar to adults who ingested vitamin D2 or vitamin D3 supplements. (Photobiology of vitamin D in mushrooms and its bioavailability in humans)

A randomized controlled trial published in the European Journal of Clinical Nutrition. This artical found that vitamin D2 enhanced button mushrooms were effective in improving vitamin D status in adults. 

While it is important to note that some researchers claimed that vitamin D3 is much more effective than vitamin D2 at raising overall vitamin D status. There are studies that suggest otherwise, including this one published in the Journal of Clinical Endocrinology and metabolism.

In summary, mushrooms can synthesize vitamin D2 when exposed to sunlight through Ergosterol. Increasing the surface area of our mushrooms by slicing them thinly and exposing the gills or pores to the sun can facilitate this conversion.

Vitamin D2 from mushrooms can be effective in improving vitamin D status in the human body, moving forward let’s discuss a lesser-known and a quite underappreciated nutrient Ergothioneine.

#3 ERGOTHIONEINE 

Ergothioneine is an amino acid that was first discovered more than a century ago. In recent years, researchers have published numerous studies on the needs and role of Ergothioneine as an important nutrient.

Some researchers suggest promoting this amino acid to vitamin status. There are two really interesting things about Ergothioneine.

Firstly, the human body cannot create it, so we must consume it if we want to obtain it. There are few food sources that contain Ergothioneine. Only fungi and a few microorganisms are capable of creating this amino acid.

Second, our bodies contain a unique transport system that moves Ergothioneine into our cells. Ergothioneine is an antioxidant and in the organisms that consume Ergothioneine, like humans consuming mushrooms, ergo thymine may act as an antioxidant by protecting our cells and our DNA against damage.

In this study (The bioavailability of ergothioneine from mushrooms (Agaricus bisporus) and the acute effects on antioxidant capacity and biomarkers of inflammation) researchers noted a significant increase in Ergothioneine content within the red blood cells of participants who consumed mushroom powder with their meals. Interestingly, as participants increased their mushroom consumption, their Triglyceride response was blunted, suggesting that mushrooms containing Ergothioneine may aid in reducing the risk of cardiovascular disease.

Another study found that Ergothioneine levels in Parkinson’s disease patients were significantly lower than the levels found in individuals without Parkinson’s disease. These results suggest that higher Ergothioneine levels in the body could be protective against the development of Parkinson’s disease. (Identification of novel biomarkers for Parkinson’s disease by metabolomic technologies)

Inadequate intake of Ergothioneine could predispose someone to the onset of neurodegenerative disorders. Now an important question to ask ourselves is, do all mushrooms contain similar levels of Ergothioneine? Already, certain mushrooms outperform others, well levels certainly vary within the fungal Kingdom, there are a few mushrooms that really stand out. (Micronutrients and Bioactive Compounds in Mushrooms)

Mushrooms with high levels of Ergothioneine include Shiitake mushrooms, Oyster mushrooms, Maitake mushrooms and King oyster mushrooms. Although Portobello, Cremini and White button mushrooms contain Ergothioneine, the levels in these mushrooms are much lower.

Ergo thiamine is an amino acid produced by fungi, this compound acts as an antioxidant. The fact that a specific transporter for its uptake is found in our bodies suggests that Ergothioneine may be positively associated with human health.

#4 B VITAMINS 

Next up well be discussing B vitamins! Many edible mushrooms are great sources of B vitamins, and here’s why.

B vitamins of which there are many are responsible for the metabolism of carbohydrates, fats and proteins in our bodies. Insufficient levels of it would disrupt many enzymatic processes involved in the metabolism of food. Because B vitamins are water-soluble, we have to eat foods that constantly replenish them. 

VITAMIN B2

So which edible mushrooms are great sources of which B vitamins? Well let’s start with vitamin B2, also known as Riboflavin. One particular study discovered that the Riboflavin content in mushrooms were higher than that generally found in vegetables. In white button mushroom varieties the contents of Riboflavin were as high as those found in eggs and cheese. (Contents of vitamins, mineral elements, and some phenolic compounds in cultivated mushrooms)

VITAMIN B3

White button mushrooms, Oyster mushrooms and Shiitake mushrooms are a good sources of vitamin B3, also known as Niacin. Levels of it in mushrooms were found to be similar to those found in many vegetables. Additionally, there is a substantial body of research demonstrating that many edible mushrooms are excellent sources of Folate.

VITAMIN B12

Now things get really interesting when we start to talk about vitamin B12. This is an absolutely essential nutrient that is mostly concentrated in foods derived from animals.

Deficiencies of B12 can lead to impaired cell division and permanent nerve damage. It’s not always easy to tell which foods contain a form of vitamin B12 that’s usable by the human body. Some nutrition labels may say that a particular food contains vitamin B12, but what many products actually contain is a biologically inactive form of B12, known as Pseudo vitamin B12.

Vitamin B12 and pseudo vitamin B12 are not the same thing! Only the former vitamin B12 is biologically active, and therefore is able to correct deficiencies in the human body. Pseudo vitamin B12 molecules have a chemical structure very similar to that of vitamin B12 but it cannot be utilized by the body.

While many mushrooms contain little to no vitamin B12, two mushrooms actually contain adequate amounts. Research has shown that certain species of Black trumpet and Chanterelle mushrooms contain considerable amounts of biologically active vitamin B12. (Characterization of vitamin B12 compounds in the wild edible mushrooms black trumpet)

While an adult would need to eat a lot of mushrooms to reach the RDA for B12. Researchers concluded that moderate mushroom intake may slightly contribute to prevention of severe B12 deficiency in vegetarians. 

Certain mushroom species can be a good source of many B vitamins, particularly Riboflavin, Niacin and also Folate. Additionally, black trumpet and Chanterelle mushrooms contain B12. Generally speaking, B vitamins play significant roles as important cofactors in a wide variety of metabolic processes in the body.

FIBER

Next up let’s talk about fiber. Although fiber is not technically classified as a nutrient, mushrooms still contain it, and it is associated with positive health benefits.

Dietary fiber consists of non-digestible carbohydrates that do not break down in the intestinal tract. There are two broad categories of fiber, the first being soluble fiber which dissolves and thickens in water. Then there’s insoluble fiber which is the roughage which speeds a passage of food through the digestive tract.

Many people in South Africa do not consume enough fiber as part of their diets. That’s unfortunate because there’s a lot of good research suggesting that fiber intake is associated with weight loss, positive effects on our gut microbiome, and reduced risks of some types of cancer.

So, how do mushrooms fit into all of this? Well mushrooms certainly contain fiber, including chitin and beta glucans which are the main component of the cell walls of fungi.

So, first, how much fiber do mushrooms contain? Well according to this study (Commercial mushrooms: nutritional quality and effect of cooking) the total fiber content in some mushroom’s ranges from 2 to 12 grams per 100 grams of edible weight, and 100 grams equals about one and a half cups of mushrooms.

Bolete mushrooms contain the highest amount of fiber with around 12 grams per 100 grams of edible weight. Just as a reference the daily recommended intake here in the South Africa is at least 25 grams for adults. Interestingly, the amount of insoluble fiber was much higher than the amount of soluble fiber in all mushrooms. Some studies suggest that consuming insoluble fiber may be associated with a reduced risk of type 2 diabetes.

WOOD EAR MUSHROOMS 

To provide one more example of the benefits of consuming fiber for mushrooms, let’s look at a study on wood ear mushrooms. Wood ear mushrooms are known to be very high in fiber.

This study found that participants with constipation symptoms improves significantly after taking fiber supplements containing wood ear mushrooms.(Effect of ear mushroom (Auricularia) on functional constipation)

In summary, mushrooms are great sources of fiber, particularly insoluble Fiber. These fibers include Chitin and Beta glucans, which are components of the cell walls of fungi. 

Adequate fiber intake is associated with increased satiety, a healthy gut microbiome and reduced risk of type 2 diabetes. Bolete mushrooms and wood ear mushrooms contain higher amounts of fiber compared to other edible mushrooms.

#5 COGNITIVE IMPAIRMENT AND DEMENTIA 

Up until now we’ve been talking about the nutritional compounds and molecules found specifically within edible mushrooms. For the next couple paragraphs let’s talk let’s talk about cognitive impairment and dementia. Let’s also look at some of the research involving general edible mushroom consumption and the reduced risks of disease at the population level.

This study looked at the relationship between mushroom consumption and dementia in over 13,000 individuals over the age of 65. (Mushroom consumption and incident dementia in elderly japanese: The Ohsaki cohort 2006 study).

The researchers found that, after controlling for other variables, mushroom consumption was associated with a decreased risk of developing dementia. This association was dose dependent, meaning those who consumed mushrooms on three or more occasions per week had a lower risk of developing dementia. Researchers concluded that habitual mushroom consumption may have a preventive effect against the incident risk of dementia.

In a large study looking at the dietary habits of over 600 participants aged 60 and above. Researchers found that participants who consumed more than two portions of mushrooms per week had reduced risks of experiencing mild cognitive impairment compared to participants who consumed less than one portion of mushrooms per week. (The Association between Mushroom Consumption and Mild Cognitive Impairment: A Community-Based Cross-Sectional Study in Singapore)

So, generally speaking there seems to be a correlation between mushroom consumption, reduced risk of dementia and cognitive impairment. As observed in the latter two studies, the risks of disease decreased with an increased frequency of mushroom consumption.

#6 CANCER 

For number six, while we’re still on the topic of general mushroom consumption at the population level, let’s look at mushroom consumption and its association with reduced cancer risk.

So, similar to what I said about mushrooms and cognitive health, a lot of the studies involving mushrooms and cancer involve medicinal mushrooms. All that research is valuable and I strongly encourage you to look into it, but we’re not going to dive into the anti-cancer effects of medicinal mushrooms in this artical. Instead, we are going to look at the association between edible mushroom consumption and reduced risk of cancer. We’re going to do this by briefly analysing three large studies.

The first study used the same data and showed that mushroom consumption reduced the risk of dementia. (Mushroom consumption and incident risk of prostate cancer in Japan: A pooled analysis of the miyagi cohort study and the ohsaki cohort study).

This time, researchers assessed over 35,000 individuals, all men, and discovered that mushroom consumption was linked to a lower risk of developing prostate cancer. Men who consumed mushrooms three or more times per week had less of a risk compared to men who consumed mushrooms on average less than once per week. 

When it comes to mushroom consumption and breast cancer, two particular studies are relevant. A study published in Nutrition and Cancer found that pre-menopausal women who had a high consumption of mushrooms had lower risks of breast cancer.(Dietary mushroom intake and the risk of breast cancer based on hormone receptor status). In this study, the most commonly eaten mushrooms were Oyster mushrooms, Shiitake mushrooms, Button mushrooms and Enoki mushrooms.

In a meta-analysis that included 10 studies with over 6,000 cases evaluated, researchers reported a potential inverse association between mushroom intake and the risk of breast cancer. (Dietary mushroom intake may reduce the risk of breast cancer: evidence from a meta-analysis of observational studies)

Now, of course, some of the studies referenced in this article have limitations, particularly the observational studies regarding cancer and dementia. Although, when we put all the research together and we consider just how many more studies there are that I didn’t reference in this artical. It’s hard to imagine that mushroom consumption would not be linked to any positive health outcomes. I didn’t even mention the presence of minerals like Selenium, Copper, and the powerful antioxidant, Glutathione 

All this to say, there’s a great deal of research suggesting that adding a few mushrooms to our meals on a daily or weekly basis can lead to significant health outcomes. 

The question is: What will you do with the presented information? It’s one thing to study, it’s another thing entirely to act!

Thanks for reading.