Can Mushrooms Help Prevent Cognitive Decline?

Edible mushrooms are an unassuming superfood with health benefits that can rival even the most nutritious vegetables. Mushrooms — which are fungi, not plants — have recently been shown to support brain health, such that they may slash your risk of cognitive decline even if you eat them only twice a week.¹

Considering mushrooms are widely available, relatively inexpensive and suitable for a wide variety of culinary uses — not to mention delicious — adding them to your diet may be one of the simplest ways to support your brain health — and more.

Mushrooms May Prevent Mild Cognitive Impairment

Researchers from the National University of Singapore (NUS) used data from 663 participants aged 60 and over to determine if eating mushrooms had an effect on cognitive function. They tracked the consumption of common mushrooms in Singaporean cuisine, including the following:

Along with this dietary measure, the researchers measured the participants' cognitive function using standard neuropsychologist tests and gathered information about their medical history, demographics and more.

Each person was then rated on a scale of dementia symptoms to gauge whether they were suffering from mild cognitive impairment (MCI), which is defined by a noticeable decline in cognitive abilities that do not yet interfere with most daily functions. It turned out that, compared with people who ate mushrooms less than once per week, those who ate mushrooms twice or more per week had a 50% lower risk of MCI.

One portion was defined as three-quarters of a cup of cooked mushrooms, or 150 grams, which is a reasonable amount to add to your diet. Further, even eating one portion of mushrooms a week offered some benefit in reducing rates of MCI.

Study author Lei Feng, assistant professor in the department of psychological medicine at NUS, said in a news release, “This correlation is surprising and encouraging. It seems that a commonly available single ingredient could have a dramatic effect on cognitive decline.”²

Mushrooms Contain Ergothioneine, the Master Antioxidant

Mushrooms have many beneficial compounds, including nutrients such as fiber, vitamins B and C, calcium, potassium, phosphorus, magnesium, selenium, and zinc, but one that may be particularly beneficial for brain health is ergothioneine (ET), which is sometimes referred to as a master antioxidant.

Previous research showed that people with MCI had lower levels of ET than their peers, leading researchers to believe it may play a role in neurodegeneration.³ The compound inhibits oxidative stress and protects against neuronal injury from substances including chemotherapy, even enhancing cognition in laboratory studies.⁴

ET has also been shown to be protective against memory loss and loss of learning abilities in mice, as well as protect against such losses due to beta-amyloid peptides, which are neurotoxic and known to contribute to the development of Alzheimer's disease.⁵

Preliminary research has even found that countries with more ET-rich diets have lower rates of neurodegenerative diseases compared to those with less ET in their diets.

“[W]hether that's just a correlation or causative, we don't know. But, it's something to look into, especially because the difference between the countries with low rates of neurodegenerative diseases is about 3 milligrams per day, which is about five button mushrooms each day,” said Robert Beelman, Professor Emeritus of food science and director of the Penn State Center for Plant and Mushroom Products for Health, in a news release.⁶

Beelman and colleagues conducted research showing that porcini mushrooms have the highest levels of ET among the varieties they tested.⁷ They also contain high levels of glutathione, another antioxidant that may help slow or ameliorate the progression of neurodegenerative disorders.⁸

What Is Mild Cognitive Impairment?

MCI is a slight decline in cognitive abilities that increases your risk of developing more serious dementia, including Alzheimer's disease (although it is by no means a guarantee). It's estimated that up to 20 percent of people aged 65 and older may have MCI.⁹

Simply misplacing your keys on occasion is not cause for alarm, however forgetting important information that you would have normally recalled, such as appointments, conversations or recent events, maybe a sign. You may also have a harder time making sound decisions, figuring out the sequence of steps needed to complete a task, or judging the time needed to do so.

If you've been diagnosed with MCI, be aware that some cases do not progress and may even improve. Regular exercise, proper diet and engaging in mentally and socially stimulating activities may help to boost your brainpower, and as the featured study suggests, eating mushrooms may help prevent MCI.

In one Japanese study, frequent mushroom consumption was once again linked to a lower risk of cognitive impairment, in this case dementia,¹⁰ while a review of more than 20 “brain-improving culinary-medicinal mushrooms” and their active compounds (at least 80 in all) revealed they “reduced beta-amyloid-induced neurotoxicity and had anti-acetylcholinesterase, neurite outgrowth stimulation, nerve growth factor (NGF) synthesis, neuroprotective, antioxidant, and anti-(neuro)inflammatory effects.”¹¹

Those researchers also concluded, “Mushrooms can be considered as useful therapeutic agents in the management and/or treatment of neurodegeneration diseases.”¹²

There Are More Than 2,000 Species of Edible or Medicinal Mushrooms

As noted in the Journal of Traditional and Complementary medicine, more than 14,000 species of mushrooms have been identified (it's believed that more than 140,000 exist¹³), with more than 2,000 of them being edible and/or medicinal.¹⁴ The researchers are calling for more research into the different types to identify those that may provide the most potent benefits to brain health, specifically as the population ages.

With an estimated 80 to 90 million people expected to reach age 65 or over in 2050, many of whom may be affected by age-related neurodegenerative disorders, the researchers noted:¹⁵

“Scientific validation is needed if these mushrooms are to be considered and this can be achieved by understanding the molecular and biochemical mechanisms involved in the stimulation of neurite outgrowth.

Though it is difficult to extrapolate the in vitro studies to what may happen in the human brain, studies have shown that there can be an improvement in the cognitive abilities of the aged if the mushroom is incorporated in their daily diets.”

Further, by 2020, it's expected that neurodegenerative diseases such as dementia and Alzheimer's may affect 42 million people. Drug strategies have failed to provide solutions, but nature-based nutraceuticals, including mushrooms and mushroom extracts, are showing promise, not only due to their antioxidant potential but also because of immune-modulating effects.

“A number of edible mushrooms have been shown to contain rare and exotic compounds that exhibit positive effects on brain cells both in vitro and in vivo … In short, these mushrooms may be regarded as functional foods for the mitigation of neurodegenerative diseases,” researchers wrote in the Journal of Medicinal Food.¹⁶

Mushrooms Provide Multifaceted Benefits

It's not only your brain that benefits when you eat mushrooms, as medicinal varieties possess a plethora of potent medicinal properties, including:¹⁷

Long-chain polysaccharides, particularly alpha and beta-glucan molecules, are primarily responsible for mushrooms' beneficial effect on your immune system. In one study, adding one or two servings of dried shiitake mushrooms was found to have a beneficial, modulating effect on immune system function.¹⁸

While there are at least 126 medicinal functions attributed to mushrooms, polysaccharides have received special attention and been the subject of a number of research studies.

According to the International Journal of Medicinal Mushrooms, “The most important for modern medicine are polysaccharides with antitumor and immunostimulating properties. Several of the mushroom polysaccharide compounds have proceeded through phase I, II, and III clinical trials and are used extensively and successfully as drugs in Asia to treat various cancers and other diseases.”¹⁹

For instance, turkey tail mushrooms contain polysaccharide K (PSK), which is approved in Japan to treat cancer. In the U.S., the National Institutes of Health-sponsored a clinical trial in which a turkey tail mushroom product was given to patients with breast cancer following radiation therapy.

These patients had an increase in cancer-fighting cells in the immune system.²⁰ Ganoderic acid in reishi mushrooms may be useful in treating lung cancer.²¹

Beyond Brain Health: What Are Mushrooms Good For?

In addition to supporting brain health and fighting cancer, mushrooms have a protective effect on mitochondria, the powerhouse of your cells, and their polysaccharides are believed to offer antiaging activity.²²

The mushroom extract has also been shown to modulate gut bacteria, leading to a host of additional benefits, including helping with weight management and insulin resistance. The mushroom acts as a form of prebiotics that encourages the growth of beneficial microbes.

According to one study published in Nature Communications, “Our results indicate that Glucidum [Ganoderma lucidum is a medicinal mushroom commonly known as Lingzhi in China and reishi in Japan] and its high molecular weight polysaccharides may be used as prebiotic agents to prevent gut dysbiosis and obesity-related metabolic disorders in obese individuals.”²³

The beta-glucan in mushrooms, known for their anticancer and immunity-stimulating effects, even plays a role in fat metabolism and may help support weight loss and healthy cholesterol levels.²⁴Taken together, mushrooms are a true superfood, as noted by one Food Chemistry review:²⁵

“Mushrooms are rich in anti-inflammatory components, such as polysaccharides, phenolic and indolic compounds, mycosteroids, fatty acids, carotenoids, vitamins, and biometals. Metabolites from mushrooms of the Basidiomycota taxon possess antioxidant, anticancer, and most significantly, anti-inflammatory properties.

Recent reports indicate that edible mushroom extracts exhibit favorable therapeutic and health-promoting benefits, particularly in relation to diseases associated with inflammation. In all certainty, edible mushrooms can be referred to as a ‘superfood' and are recommended as a valuable constituent of the daily diet.”

For more information on the many health benefits of mushrooms, check out the infographic below.

Mushrooms are packed with numerous vitamins, minerals, and antioxidants that provide outstanding health benefits. Discover more about this emerging superfood through this infographic. Use the embed code to share it on your website.

<img src="https://media.mercola.com/assets/images/infographic/mushrooms.jpg" alt="mushrooms" border="0" style="max-width:100%; min-width:300px; margin: 0 auto 20px auto; display:block;"><p style="max-width:800px; min-width:300px; margin:0 auto; text-align:center;">Mushrooms are packed with numerous vitamins, minerals, and antioxidants that provide outstanding health benefits. Discover more about this"<a href="https://www.mercola.com/infographics/mushrooms.htm">emerging superfood</a>." through this infographic. Use the embed code to share it on your website.</p>