Many different plants and fungi are used in Eastern medicine. Surprisingly, the reishi mushroom is extremely popular.
It has a number of potential health benefits, including immune system stimulation and cancer prevention. Its safety, however, has recently been called into question.
This article will inform you about the potential benefits and risks of reishi mushroom.
What Exactly Is the Reishi Mushroom?
The reishi mushroom, also known as Ganoderma lucidum and lingzhi, is a fungus that grows in hot, humid areas of Asia (1).
This fungus has been used in Eastern medicine for many years (1, 2).
Several molecules found within the mushroom, including triterpenoids, polysaccharides, and peptidoglycans, may be responsible for its health benefits (3).
While the mushrooms can be eaten fresh, powdered forms of the mushroom or extracts containing these specific molecules are also popular.
These various forms have been investigated in cell, animal, and human studies.
The following are six scientifically proven reishi mushroom benefits. The first three are supported by more evidence, while the others are less conclusive.
1. Immune System Boost
One of the most significant benefits of the reishi mushroom is that it can strengthen your immune system (4).
While some details are still unknown, test-tube studies have shown that reishi can influence the genes in white blood cells, which are important components of your immune system.
Furthermore, these studies have discovered that certain types of reishi may alter inflammation pathways in white blood cells (5).
Some of the molecules found in the mushroom have been shown in cancer patients to increase the activity of a type of white blood cell called natural killer cells (6).
Natural killer cells defend the body against infections and cancer (7).
Another study discovered that reishi can boost the number of white blood cells (lymphocytes) in people with colorectal cancer (2).
Although most of the immune system benefits of reishi mushroom have been seen in sick people, some evidence suggests that it can also help healthy people.
In one study, the fungus improved lymphocyte function in athletes exposed to stressful conditions, which aids in the fight against infections and cancer (8, 9).
Other studies in healthy adults, however, found no improvement in immune function or inflammation after 4 weeks of taking reishi extract (10).
Overall, it is obvious that reishi has an effect on white blood cells and immune function. More research is required to determine the extent of the benefits in both healthy and ill people.
Reishi mushroom can boost immune function by influencing white blood cells, which aid in the fight against infection and cancer. This may occur primarily in the sick, as mixed results have been observed in the healthy.
2. Cancer-Resistant Properties
Because of its potential cancer-fighting properties, this fungus is consumed by a large number of people (11, 12).
In fact, one study of over 4,000 breast cancer survivors discovered that approximately 59% consumed reishi mushroom (13).
Furthermore, several test-tube studies have shown that it can cause cancer cells to die (14, 15, 16).
However, the findings of these studies do not always imply efficacy in animals or humans.
Some studies have looked into whether reishi could help with prostate cancer because of its effects on the hormone testosterone (17, 18).
While one case study found that molecules found in this mushroom could reverse prostate cancer in humans, a larger follow-up study found that these findings were not supported (19, 20).
Reishi mushroom has also been studied for its potential role in the prevention or treatment of colorectal cancer (2, 21).
According to one study, one year of reishi treatment reduced the number and size of tumours in the large intestine (21).
Furthermore, a comprehensive review of multiple studies found that the mushroom can benefit cancer patients (22).
These advantages included increased activity of the body's white blood cells, which aid in the fight against cancer, as well as improved quality of life in cancer patients.
However, researchers believe that reishi should be used in conjunction with traditional treatment rather than in place of it (22).
Furthermore, many studies on reishi mushroom and cancer were of poor quality. As a result, much more research is required (11, 23).
Although the reishi mushroom appears to hold some promise for cancer prevention or treatment, more research is required before it can be included in standard therapy. However, in some cases, it may be appropriate to use in addition to standard care.
3. May Help With Fatigue and Depression
Reishi's immune-boosting properties are frequently highlighted, but it also has other potential benefits.
These include decreased fatigue and depression, as well as an overall improvement in quality of life.
One study looked at its effects in 132 people who had neurasthenia, a poorly defined condition characterised by aches and pains, dizziness, headaches, and irritability (24).
After 8 weeks of taking the supplements, the researchers discovered that fatigue was reduced and well-being improved.
Another study found that taking reishi powder for four weeks reduced fatigue and improved quality of life in a group of 48 breast cancer survivors (25).
Furthermore, the participants in the study reported less anxiety and depression.
While the reishi mushroom may hold promise for people suffering from specific diseases or illnesses, it is unclear whether it will benefit those who are otherwise healthy.
Preliminary research suggests that reishi mushroom may reduce anxiety and depression, as well as improve quality of life in people with certain medical conditions.
4–6. Additional Potential Benefits
Reishi mushroom has been studied for its potential to improve other aspects of health in addition to its effects on the immune system and quality of life.
4. Cardiovascular Health
Reishi mushroom may increase "good" HDL cholesterol and lower triglycerides, according to a 12-week study of 26 people (26).
Other studies in healthy adults, however, found no improvement in these heart disease risk factors (10).
Furthermore, a large analysis of five different studies involving approximately 400 people found no beneficial effects for heart health. The researchers discovered that eating reishi mushrooms for up to 16 weeks did not improve cholesterol levels (27).
Overall, more research on reishi mushrooms and heart health is required.
5. Blood Sugar Management
Several studies have found that molecules found in the reishi mushroom can lower blood sugar levels in animals (28, 29).
Some preliminary human research found similar results (30).
The majority of research, however, has not supported this benefit. Researchers discovered no benefits to fasting blood sugar levels after evaluating hundreds of participants (27).
Blood sugar levels after meals produced mixed results. In some cases, reishi mushroom reduced blood sugar levels, but in others, it was no better than a placebo. More research is required here as well.
Antioxidants are molecules that can help prevent cell damage (31).
Because of this critical function, there is a lot of interest in foods and supplements that can boost the body's antioxidant status.
Many people believe that the reishi mushroom can help with this.
Several studies, however, have found no change in the levels of two important antioxidant enzymes in the blood after 4 to 12 weeks of consuming the fungus (10, 26).
A small amount of research has suggested that the reishi mushroom may improve good cholesterol or blood sugar levels. The majority of research, however, indicates that it does not improve cholesterol, blood sugar, or antioxidant levels in the body.
The recommended dosage varies. Depending on the Form
Unlike some foods or supplements, the dose of reishi mushroom can vary significantly depending on the type used (12).
The highest doses are obtained when the mushroom is consumed. In these cases, depending on the size of the mushroom, doses can range from 25 to 100 grammes (32, 33).
Instead, a dried extract of the mushroom is commonly used. The dose is approximately ten times lower in these cases than when the mushroom is consumed (10).
For example, 50 grammes of reishi mushroom may be equivalent to about 5 grammes of mushroom extract. Doses of mushroom extract vary, but typically range from 1.5 to 9 grammes per day (27).
Furthermore, some supplements only use a portion of the extract. The recommended doses in these cases may be much lower than the values reported above.
Because the recommended dose varies greatly depending on the form of the mushroom used, it is critical to understand which type you are taking.
Because the dose of reishi mushroom varies depending on the form of the fungus, it is critical to understand which form you are using. Consuming the mushroom directly results in higher doses, whereas extracts result in lower doses.
Dangers and Potential Side Effects
Despite its popularity, some have questioned the safety of the reishi mushroom.
According to one study, those who took reishi mushroom for four months were nearly twice as likely as those who took a placebo to experience a side effect (22).
These side effects, however, were minor, and included a slightly increased risk of stomach upset or digestive distress. There were no reported adverse effects on liver health.
Another study found that taking reishi mushroom extract for four weeks had no negative effects on the liver or kidneys in healthy adults (10).
In contrast to these reports, two case studies have revealed significant liver problems (34, 35).
Both participants in the case studies had previously used reishi mushroom without incident but experienced negative effects after switching to a powdered form.
This makes it difficult to determine whether the mushroom caused the observed liver damage or if there were issues with the powdered extract.
It is also important to note that many reishi mushroom studies have not reported safety data, so there is limited information available overall (22).
Nonetheless, there are a few people who should probably avoid reishi.
Those who are pregnant or breastfeeding, have a blood disorder, are having surgery, or have low blood pressure are among those who qualify (36).
Some reishi mushroom studies have not provided safety information, but others have reported that taking it for several months is likely safe. Nonetheless, reishi extract has been linked to several cases of severe liver damage.
The reishi mushroom is a well-known fungus in Eastern medicine.
It may strengthen the immune system by affecting white blood cells, especially in people who are ill, such as those with cancer.
This fungus may also be capable of reducing tumour size and number in certain types of cancer, as well as improving quality of life in some cancer patients.
The majority of human research has shown that it does not improve cholesterol, blood sugar, or antioxidants, but it may be effective in some cases in reducing fatigue or depression.