What are the benefits of functional mushrooms? Here are 9 types worth exploring.

Perhaps you’ve watched the Fantastic Fungi documentary on Netflix or noticed your favorite influencer raving about functional mushrooms—sparking your curiosity about this rapidly growing food trend. With more food, beverages, and wellness supplements incorporating these powerful fungi, functional mushrooms are gaining widespread popularity. The global functional mushroom market is projected to exceed 19 billion dollars by 2030.

So, what exactly are functional mushrooms, and how do they differ from the shiitake, morel, and button mushrooms you’re familiar with? Are the health claims surrounding these medicinal mushrooms backed by science? Consider this your introduction to functional mushrooms—let's dive in.

What Are Functional Mushrooms?

Mushrooms come in a vast array of types: some are poisonous, others have psychedelic effects, while some are edible and nutritious, making them excellent choices for cooking. Among them, functional mushrooms stand out for their remarkable health benefits when consumed.

Not all functional mushrooms offer the same health benefits, but each can provide unique advantages for the body. "Functional mushrooms are fungi that possess adaptogenic properties and offer health benefits beyond basic nutrition," says Abbey Sharp, registered dietitian.

What exactly are adaptogens?

Advantages of Medicinal Mushrooms

The term 'adaptogen' was first introduced in the 1940s, referring to a class of compounds in plant-based foods (which can also be synthesized) that assist the body in responding to various types of stress, whether chemical, biological, or physical. These compounds support our resistance to diseases that might result from such stressors and help maintain balance within the body.

A study reviewing the overall effectiveness of adaptogens in preventing illness, as well as their ability to combat viral respiratory infections, concluded that these substances activate the immune system, reduce inflammation, detoxify and repair damaged cells, have antiviral effects, and generally enhance overall well-being. Quite impressive results overall.

For millennia, ancient cultures have harnessed the medicinal properties of the unique compounds found in functional mushrooms. Currently, there are over 70 known adaptogens in nature, including both plants and various mushrooms. Among the most prominent adaptogenic mushrooms are lion’s mane, chaga, tremella, reishi, cordyceps, shiitake, maitake, oyster, and turkey tail mushrooms.

Varieties of Medicinal Mushrooms

While each mushroom has its own distinct nutritional makeup, many varieties share similar benefits. A common theme among them is the immune-boosting plant compounds (phytonutrients) they all contain. According to Sharp, there is 'evidence to support functional mushroom use for supporting a healthy immune system, stress response, exercise performance, and brain health.' While most studies remain small-scale, in vitro, or animal-based, there is enough human research to suggest that these mushrooms may possess unique health-enhancing properties.

Although large-scale studies have yet to fully validate the claims, mushrooms in general offer a wealth of health benefits, especially for the brain, bones, and digestive system, thanks to their abundance of essential minerals and phytochemicals. Let’s explore some of the standout functional mushroom varieties and the scientific research that highlights why they’re considered such powerful health foods.

1. Lion’s Mane Mushrooms

Lion’s mane is often one of the first mushrooms that come to mind when discussing functional varieties. These white mushrooms, which resemble furry little brains, are renowned for their ability to promote brain health due to their neurotrophic properties.

Neurotrophic factors encourage the growth and specialization of neurons, the brain cells responsible for transmitting and receiving information. Lion’s mane is also linked to reducing brain inflammation, offering neuroprotective effects. It has even been associated with slowing or preventing cognitive decline in patients with Alzheimer's disease.

In addition to its benefits for the brain, this mushroom has been shown to possess anti-inflammatory, anti-bacterial, and anti-cancer properties. It also supports heart and digestive health. Lion’s mane is rich in B vitamins, zinc, potassium, and iron, which aid in energy metabolism, immune health, fluid balance, and red blood cell production. Moreover, it’s packed with beta-glucan, a fiber type that supports gut health, immunity, and metabolic function.

Lion's mane mushrooms are becoming more widely available, particularly from local mushroom growers. They are often used as a vegan alternative to seafood due to their shellfish-like texture.

2. Chaga Mushrooms

While fresh chaga mushrooms are hard to come by, they offer impressive health benefits. These fungi resemble truffles more than typical mushrooms, with a vibrant orange interior that looks similar to turmeric. A review of current research found that chaga is a powerful antioxidant, anti-inflammatory, anti-viral, and cholesterol-lowering agent. The study also suggested that chaga could be a promising treatment for type 2 diabetes and cancer.

Further research supports these claims, showing that chaga mushroom extract can block key signaling pathways essential for breast cancer cell growth. Other findings indicate that it may benefit both gut and brain health. In fact, some studies suggest it could even help manage COVID-19 symptoms. Additionally, chaga is a rich source of beta-glucans, vitamin D, zinc, B vitamins, copper, manganese, and potassium.

However, chaga is very high in oxalate, a naturally occurring substance found in plants. Excessive oxalate intake over time can lead to kidney stones and even kidney failure. Several case studies have linked chaga consumption to kidney issues. One such case involved a 69-year-old man who developed oxalate-induced nephrotic syndrome after consuming 15 to 20 grams of chaga daily for three months. Therefore, it's important to consume chaga in moderation. Experts recommend a daily intake of around 2 grams of chaga powder, or one tablespoon, to enjoy the health benefits while minimizing the risk of excessive oxalate consumption.

3. Tremella Mushrooms

Often affectionately called 'snow fungus,' tremella mushrooms have a delicate, ribbon-like appearance, reminiscent of a cluster of white seaweed. These mushrooms are typically available in supplement form, such as powder, tinctures, or capsules. While they are not as extensively studied as some other varieties, the available research on tremella is quite promising.

A 2023 review of research on tremella found it to possess antioxidant, antitumor, immune-modulating, blood sugar-regulating, and neuroprotective qualities. Like many other functional mushrooms, tremella provides B vitamins, vitamin D, zinc, copper, calcium, and iron, which help support immunity, bone health, and red blood cell production.

4. Reishi Mushrooms

Reishi mushrooms are among the most widely used functional mushrooms. If you're familiar with the world of health foods, you'll often find them incorporated into various functional health products. However, this mushroom has a long history of use in traditional Chinese medicine, where it has been revered for its supposed ability to promote overall health and longevity.

A 2021 review of the available evidence highlighted this mushroom's potential therapeutic effects on conditions such as inflammation, diabetes, heart disease, neurological disorders, cancer, mood disorders, and liver disease. However, the review also points out that much of the evidence surrounding this mushroom is still in its early stages, and further research is needed to establish causality for these effects.

In terms of nutrients, this mushroom is packed with immune-boosting vitamins E, C, and D, along with B vitamins and the plant pigment beta carotene, which is particularly known for its benefits in supporting eye health.

5. Cordyceps Mushrooms

Cordyceps, which gained fame through The Last of Us (without the apocalyptic threat, of course), are fascinating mushrooms with a unique appearance, resembling long, golden caterpillars. Interestingly, they actually grow on insect larvae.

In addition to its fascinating appearance, cordyceps mushrooms have attracted considerable research attention. Studies suggest that they may have beneficial effects on respiratory health, various types of cancer, blood sugar control, kidney disease, and overall inflammation in the body. They might also help reduce exercise-induced fatigue and viral activity. However, it's crucial to note that many of these studies were conducted on animals, meaning further human-based research is needed to confirm these findings.

Cordyceps mushrooms are also a good source of protein, vitamin K, and a range of B vitamins, including B12, thiamine, and riboflavin. These nutrients provide a natural energy boost while supporting healthy blood clotting.

6. Shiitake Mushrooms

Shiitake mushrooms are loaded with essential vitamins and minerals like B vitamins, copper, and selenium. These nutrients are vital for maintaining energy levels and supporting a healthy immune system. In addition, 100 grams of shiitake mushrooms provide 2.5 grams of dietary fiber, which aids in digestive health.

Shiitake mushrooms also contain compounds such as polysaccharides, terpenoids, and sterols. These have been shown to help reduce inflammation and strengthen the immune system. One of the most noteworthy compounds in shiitake is lentinan, a beta-glucan studied for its ability to fight infections. Lentinan has also demonstrated potential in supporting cardiovascular health in individuals with diabetes. Due to their nutrient-rich content and bioactive compounds, shiitake mushrooms have been utilized in traditional medicine for centuries.

7. Maitake Mushrooms

Maitake mushrooms, often known as "hen of the woods," are packed with nutrients and bioactive compounds, making them highly beneficial for health. These mushrooms are particularly rich in beta-glucans, which can stimulate the immune system by activating immune cells such as macrophages and natural killer cells.

Studies indicate that maitake mushrooms can support metabolic and cardiovascular health. For example, they have been shown to help regulate blood sugar levels and may assist in lowering blood pressure and cholesterol, reducing the risk of heart disease. Additionally, maitakes are full of antioxidants that fight oxidative stress and inflammation, offering further protection for heart health and overall wellness.

8. Oyster Mushrooms

Oyster mushrooms are a fantastic source of B vitamins, especially niacin, riboflavin, and pantothenic acid. These nutrients play a key role in energy production, digestive health, and enhancing brain function.

Oyster mushrooms are also rich in minerals like potassium, copper, and iron, which are crucial for maintaining healthy muscle function. They are low in calories and high in dietary fiber, promoting digestive health by adding bulk to stools. Furthermore, oyster mushrooms are packed with antioxidants, which help protect the body from oxidative stress and inflammation.

9. Turkey Tail Mushrooms

Turkey tail mushrooms, with their dark brown, fan-like appearance, are reminiscent of turkey tails. Research suggests that turkey tail acts as a nonspecific immune modulator, meaning it enhances the immune system overall, functioning as an antioxidant while helping to reduce inflammation. A 2023 study highlighted its therapeutic potential for melanoma, and a 2012 study revealed similar findings for breast cancer.

Turkey tail mushrooms are also notably high in beta-glucans, vitamin D, and B vitamins. Some people prefer to eat them whole, while others opt for supplement forms.

Functional Mushroom Consumption, Safety, and Risks

We've explored the numerous health benefits of functional mushrooms, but how can we best incorporate them into our daily routine? While some mushrooms, such as lion's mane, are delicious in their whole form, others are often more convenient and enjoyable when taken as supplements—available in forms like powders, pills, or tinctures.

Check in with Your Doctor

Before introducing any new dietary supplements, including functional mushrooms, it's crucial to make informed choices, as supplements are not regulated or standardized by federal authorities. Always consult with your healthcare provider before adding anything new to your regimen. Amy Davis, RD, LDN, advises: 'Always check with your healthcare provider and research the purpose and potential side effects before supplementing with functional mushrooms.' This is particularly important if you have existing health conditions or are taking prescription medications.

'While research shows that these mushrooms are generally safe and well-tolerated, some individuals may experience side effects like dizziness or headaches. They are not recommended for people taking medication to lower blood pressure or for pregnant individuals. In rare cases, allergic reactions may occur,' says Sharp.

Look for Third-Party Certifications on Mushroom Supplements and Food Products

Although mushroom supplements are regulated by the U.S. Food and Drug Administration (FDA), they do not require pre-market approval, according to Sarah Hester, MS, RD. This means that products that may not be safe or effective can still make their way into the market and onto store shelves.

'It’s crucial to select supplements that are third-party tested to confirm their purity and safety,' says Sharp. The most trusted organizations conducting these verifications include NSF and U.S. Pharmacopeia (USP), so make sure to check for their certification seals when shopping for these products.

How to Incorporate Functional Mushrooms

Once you’ve acquired your functional mushrooms or mushroom-based products, there are several ways to add them to your routine. Whole mushrooms can be incorporated into your favorite mushroom recipes or steeped in water for a flavorful, earthy tea. If you have the supplement form, consider blending it into smoothies, stirring it into coffee, or sprinkling it over oatmeal, as recommended by Davis.

The amount of mushrooms you should use depends on the recipe or the intended health purpose. Generally, a daily serving ranges from 1 to 3 grams of whole mushrooms or approximately 250 to 500 milligrams of mushroom extract. For more accurate dosing, especially if you're using them for therapeutic reasons, it's best to follow the product's instructions or consult with a healthcare provider.

Although these functional mushrooms may not be the usual risotto addition, the evidence supporting their nutritional and health benefits is both compelling and noteworthy. After conducting your own research and speaking with your doctor, they could be a valuable addition to your diet and potentially improve your overall well-being.