THE SCIENCE OF MUSHROOMS: NUTRITIONAL VALUE AND HEALTH BENEFITS

May 9, 2017 by

The Basics of Mushrooms

What are Mushrooms Anyway?

Most people are aware that mushrooms are a type of fungus, however, many people are unaware of how complex and important mushrooms are for our health and ecosystem. Some characteristics of these fungi, without getting too biologically technical, are highlighted below:

  • Fungi “eat” by absorbing dissolved molecules from their environment (they don’t photosynthesize).
  • Fungus is defined as a group of which include yeasts, molds, and of course mushrooms.
  • They act as the main decomposers within an ecosystem.
  • Most of the time, you don’t notice fungi unless it is “fruiting” (via mushrooms or molds) which is their method of spreading spores.

In simple terms, when you eat a mushroom, you’re eating the “fruiting body” of a larger organism. The primary purpose of the fruiting body is spreading spores through the air to continue the growth of the overall organism.

Nutritional Value of Mushrooms

For the purpose of nutrition, we should consider the most commonly available mushroom in supermarkets, aptly named the “common mushroom”. These mushrooms actually come in two separate colors – white in brown. Baby Bella and Crimini mushrooms are the two types of common mushrooms you’ve likely seen.

In addition to the two most common names listed above,  they can also be called:

  • Button Mushroom
  • White Mushroom
  • Champignon Mushroom
  • Cultivated Mushroom
  • Chestnut Mushroom
  • Portabello Mushroom (when it’s fully mature)
mushrooms nutrition facts

Nutrition Facts for the Common Mushroom

Much like plant foods, mushrooms are low in calories and high in micronutrients.  While the above chart shows a low percentage of the vitamins that mushroom contains, it’s important to note that 22 calories of cooked mushrooms would be quite small in terms of portion size and daily caloric needs.

That being said, if you ate 100 calories of mushrooms, you’d be getting around 5X the micronutrient percentages listed on the nutrition facts above.​ Mushrooms also contain 0.14 grams of protein per calorie which is actually greater than chicken which has 0.11 grams per calorie. If eaten in enough quantity, mushrooms can actually be a decent lean protein source.

Studies Done on Mushrooms

Mushrooms and the Immune System

SIgA, short for Secretory immunoglobulin A, is the immune system’s first line of defense for our body’s mucosal surfaces. Mucosal surfaces are membranes made up of epithelial cells. These cells facilitate absorption and secretion in glands and intestines.

Mucosal surfaces line certain tracts and glands in the body including :

  • The Mouth
  • Gastrointestinal Tract
  • Respiratory Tract
  • Genitals
  • Breast Glands

These sites are our body’s primary ways of absorbing things from the outside world such as bacteria, viruses and toxins.

Increasing our body’s secretions of SIgA increases our initial defenses thus increasing our overall immune function.

​Researchers who conducted this study decided to put white button mushrooms to the test to see if consuming them lead to increased levels of SIgA in the saliva.

Being that the mouth is one of our body’s primary mucosal surfaces, having increased levels of SIgA in our saliva increases our ability to fight off bacteria, viruses and toxins from the outside world.

Twenty-four healthy volunteers were asked to eat their normal diet, but the volunteers in the test group were told to consume 100g of blanched white button mushrooms per day for a week. Researchers then tested the participants’ saliva. They found those in the test group had over a 50% increase of SIgA for 2 weeks, which then returned back to baseline by week 3. Researchers therefore concluded that white button mushrooms do indeed have potential health benefits for improving immune function on the body’s mucosal surfaces.

The dietary intake of A. bisporus WBM significantly accelerates sIgA secretion, thereby indicating its potential health benefits for improving mucosal immunity.​

It’s also been shown by this study (in vitro/test tube) that mushrooms won’t increase inflammation. Rather, they have an anti-inflammatory effect. This is good news for those who may have an overactive immune system from conditions such as allergies.

Some edible mushrooms species have a potential anti-inflammatory capacity in vitro, suggesting that they could be regarded as a potential source of natural anti-inflammatory agents.

See the video and link below for an expanded view of this topic.

Mushrooms and Our Immune System by Dr. Michael Greger

Mushrooms and Our Arteries

We know that CVD or cardiovascular disease is the number one killer in Western and developed countries.

“The etiology (development) of CVD involves, in part, a complex process of development and deposition of cholesterol ladened fatty streaks within aortic blood vessels and appears associated with oxidative stress and inflammation” (source)

To simply summarize, the first level of protection against cardiovascular disease would to avoid high levels of bad (LDL) cholesterol in the blood. The next level of prevention would be avoiding inflammation so that fatty arterial streaks are not developed. In periods of inflammation, certain processes such as monocyte adhesion can occur:

Monocytes are white blood cells that can potentially get absorbed into the cardiovascular system hence the term monocyte adhesion.

These researchers conducted an experiment in vitro (test tube / culture dish) to see if specialty and common mushrooms can inhibit certain cellular processes that are associated with inflammation in the arteries (such as binding of monocytes), which is associated with CVD.

Here’s what happened:

Human aortic endothelial cells were soaked in a control medium or a medium containing extracts of several different mushrooms:

  • Agaricus bisporus (white button and crimini)
  • Lentinula edodes (shiitake)
  • Pleurotus ostreatus (oyster)
  • Grifola frondosa (maitake)

​After being incubated overnight, researchers found that the cells that were incubated with the mushrooms bound significantly less monocytes in pro-inflammatory conditions which again is an associative factor of CVD.

Researchers quoted:

These data provide evidence that dietary mushrooms can inhibit cellular processes such as adhesion molecule expression and ultimate binding of monocytes to the endothelium under pro-inflammatory conditions, which are associated with CVD. As a result, these findings support the notion that dietary mushrooms can be protective against CVD.​

For those among us who are budget conscious – the common white mushroom actually performed the best, so there’s no reason to go out seeking any kind of expensive and exotic fungi.

See the video and link below for an expanded view of this topic.

Mushrooms and Our Arteries by Dr. Michael Greger

Mushrooms and Breast Cancer

Research has shown that an enzyme called aromatase plays a big role in the development of breast cancer. This enzyme is responsible for synthesizing estrogen which can be utilized by tumors to proliferate (source).

Because anti-aromatase phytochemicals are also present in plant foods such as white button mushrooms, researchers decided to investigate whether or not  white button mushroom extract in a petri dish (in vitro) could prevent the proliferation of breast cancer cells (study here).

Researchers confirmed that this was indeed the case. They concluded that:

Diets high in mushrooms may modulate the aromatase activity and function in chemoprevention in postmenopausal women by reducing the in situ production of estrogen.

In addition, based on the first study we referenced in which researchers actually tested mushroom extracts in mice – researchers concluded:

…​consumption of 100 g of mushrooms per day would be sufficient to suppress breast tumor growth in women

This means that you don’t need to eat tons and tons of mushrooms to see the benefits!

See the video and link below for an expanded view of this topic.

Mushrooms and Breast Cancer by Dr. Michael Greger

Potential Downsides of Mushrooms

Special thanks to Dr. Joel Fuhrman for pointing out this research in his article on mushrooms.​ We highly recommend that you check it out to learn more!

While it’s clear that mushrooms have a ton of benefits, it is also important to examine what some potential drawbacks may be. The primary drawback of mushrooms seem to be from consuming them raw, much like Kale which we touched on in our other article.

In this study​, scientists took the uncooked common mushroom (Agaricus bisporus) as mentioned above and fed it to mice in a feeding trial to test the very hypothesis of uncooked mushrooms being carcinogenic. Researchers were unfortunately able to induce the mice with cancerous tumors in several different areas throughout their body.

However, cooking the mushrooms does reduce their agaritine content substantially, but doesn’t degrade it completely. While the evidence on mushrooms and cancer is far from conclusive, there are still huge health benefits from eating a moderate amount of cooked mushrooms per day.

Given that researchers recommend that you would only need approximately 100 g per day to reap the benefits, we recommend eating mushrooms regularly, but not in overzealous amounts. More isn’t always better. And always cook them!

Delicious Mushroom Recipes

Mushroom and Potato Stew by The Vegan Corner

Stew can be a comforting meal on a cold winter day. Because we don’t recommend eating meat products on Thrive Cuisine, mushrooms can do the same job that meat would in a stew providing an earthy, nutty, and umami flavor as well as a different texture than vegetables. This stew is simple, delicious, and super nutritious so we suggest you give it a try!

Basic Vegan Mushroom Gravy by The Vegan Video Pantry

Mashed potatoes and gravy are one of the biggest comfort foods out there. Using mushrooms to make gravy creates some of the deepest and richest flavor notes you’re ever going to taste. The Vegan Video Pantry makes the process simple in the video above!

Portabello Mushrooms Sliders by The Edgy Veg

Because of their high protein content that we discussed before, mushrooms can actually make great burgers! In this video, the Edgy Veg shows you how to create some super simple sliders out of mushrooms and some other great vegan toppings. Enjoy!

One Pot Creamy Mushrooms Pasta by Cooking with Plants

When it comes to simplicity and deliciousness, Cooking with Plants never disappoints. This easy to create pasta dish will please the entire family without breaking a sweet in the kitchen. Highly recommended for those busy week days.

Conclusions

While they are often overlooked as health promoting foods (compared to fruits and veggies anyway), there is definitely a place for mushroom consumption in a diet focused on well-being and disease prevention. Based on what we learned throughout all the studies, regular white button mushrooms should be consumed regularly (but no need to exceed 100 g per day.)

Just be sure to cook the mushrooms before you eat them!​ Raw mushrooms don’t taste particularly good anyway!

We welcome your comments!