Reishi and Insulin Resistance.

Blood Sugar and Cholesterol Management

Reishi mushroom improved insulin and cholesterol levels in a study published in the April 2012 “British Journal of Nutrition.” Participants with slightly elevated blood pressure and cholesterol consumed 1.44 grams of reishi per day for 12 weeks. Results showed lower levels of insulin and decreased insulin resistance — an inability of cells to respond to insulin. Reishi also decreased triglycerides and increased levels of high-density lipoprotein, or HDL, the good form of cholesterol. However, reishi did not decrease blood pressure or body fat or increase antioxidant levels in this study.

Human studies with Reishi have been conducted in patients with mild hypertension and elevated blood lipids. While the results showed little change in blood pressure, the researchers found a marked reduction in serum triglycerides and a marked increase in HDL-cholesterol.

Additionally, the Reishi group saw better plasma insulin and insulin resistance results—a major risk factor for later cardiovascular disease development and diabetes—than the placebo group.56 Other research showed a reduction in the activity of an enzyme that contributes to elevated blood sugar and lipid levels.57

In diabetic rats, which like their human counterparts are at increased risk for atherosclerosis and heart disease, Reishi extract supplementation decreased fasting blood glucose and improved insulin concentrations in a manner comparable with the antidiabetic drugs metformin and rosiglitazone. The animals given Reishi had lower levels of free fatty acids, triglycerides, and total and LDL-cholesterol, and higher levels of beneficial HDL-cholesterol.


According to the Center of Disease Control and Prevention[1], diabetes mellitus is a metabolic disease that affects 8.3% of the U.S. population (25.8 million people) and is the seventh leading cause of death. While type I diabetes is dictated by genetics, type II is acquired and can be prevented. Fats and carbohydrates are important for bodily function, but a diet in excess of either without regular exercise is a recipe for diabetes. Maintaining a healthy diet and exercising are the most important actions you can take to prevent diabetes, but research has also shown that consuming certain varieties of mushrooms can aid in retarding the onset of diabetes and can help by maintaining normal blood sugar levels in patients with diabetes.

It has long been known that type II diabetes is impacted by poor diet, but it was not until a few years ago that scientists uncovered the biochemical mechanism. Type II diabetes is marked by insulin resistance, which is a defense mechanism to prevent the damaging effects of over-nutrition. Insulin is the hormone responsible for regulating the use of fats and carbohydrates for cellular energy production. When we eat a cheeseburger, the chemical components are broken apart by acids and enzymes in our digestive system. The smaller fractions are circulated throughout the blood stream to reach different parts of the body. Insulin allows sugar to be withdrawn from the blood and internalized by cells to be used for energy production. Once inside the cell, simple sugars are fed through a few pathways, the last of which is the electron transport chain (ETC). The pathways prior to the ETC transform the sugars into new molecules, and during the process electrons are stripped and attached to carrier molecules. The electron carriers take the electrons and insert them into the ETC. The electrons are passed from one enzyme to the next, and each time a transfer is made, protons are pumped out across a membrane. Because positive protons are pumped out, the space outside of the membrane becomes positively charged and the space on the inside holds a negative charge. The difference in charge means that there is an electrochemical gradient on either side of the membrane. At the end of the chain, the final enzyme allows three protons to flow back across the membrane. The protons flow in and spin a rotor–mechanically–and this spinning action pushes two molecules together. The two molecules fuse to form ATP, which is the body’s major energy molecule. The process is analogous to a reservoir with a water turbine downstream. Protons are stored in the reservoir and released to spin a turbine that creates energy for the body.

For the ETC to function properly, ATP should be used when it is available, and nutrients (fats and sugars) should be fed into the upstream pathways only when there is a demand. If sufficient ATP is already available and the upstream pathways continue to be flooded with fats and sugars, problems arise. According to researchers at the Metabolic Institute for the Study of Diabetes and Obesity[2], consuming excess fats and sugars without depleting energy stores through exercise leads to the production of radical oxygen species that damage our cells. Overloading the ETC with electron carriers leads to the leaking of electrons from the chain. Electrons leak, bond with oxygen, and melt the intracellular components. Continued over-nutrition leads to the inhibition of the metabolic pathways. It is like a manufacturing assembly line with too many raw materials and not enough workers. If the assembly line is overflowing with materials, and the workers are being injured when the supplies fall off the line, the supervisor will hit the emergency stop button. The only problem is that the supervisor doesn’t stop the shipments from being received, so even though the assembly line stops functioning, the warehouse continues to fill with incoming shipments. Over-nutrition causes the body to ignore insulin; this is insulin resistance. It is a successful strategy for preventing the production of radical oxygen species, but if we continue to eat, our blood will become saturated with sugar (hyperglycemia) because we no longer have a method for processing and withdrawing this sugar from the bloodstream.

Eating less fat and sugar and exercising is without a doubt the best strategy for maintaining insulin sensitivity, but consuming certain mushrooms can help, too. Some species of fungi promote radical scavenging, reduce oxidative damage to cells, and therefore decrease the development of insulin resistance. Studies on mice have shown that the polysaccharides in turkey tail mushrooms promote superoxide dismutase activity, an important enzyme for eliminating superoxide radicals in the mitochondria–where the ETC occurs[3]. Researchers at the Amala Institute of Medical Sciences[4] have also found reishi mushrooms to decrease oxidative stress and ameliorate the functioning of the ETC when damaged by strong oxidants. According to a study published in the Journal of Food Chemistry[5], the ability of the polysaccharides in reishi mushrooms to reduce cellular oxidation can directly or indirectly raise insulin levels and decrease blood sugar. Shiitake mushrooms have also been found to counteract the oxidative effects of high-fat diets[6].

The antioxidant properties of mushrooms are of pharmacological interest because they target the problem at the source: inside of the mitochondria where the ETC is executed. Insulin resistance is in response to oxidative damage, and the polysaccharides in fungi minimize this damage. If insulin resistance ensues, blood sugar levels can reach dangerous levels. Mushrooms should certainly not be used to treat or prevent diabetes, but supplementing with certain species may aid in restoring insulin sensitivity and decreasing the effects of over-nutrition.


ATP: Formally known as adenosine triphosphate. It plays a lot of different roles but is most commonly referenced as the “energy molecule” for its ability to transport chemical energy.

Blood Sugar Concentration: The amount of glucose in the blood. Glucose is fed into glycolysis to eventually yield large amounts of ATP at the end of the electron transport chain. Low blood sugar levels limit ATP synthesis, but high blood sugar poses its own set of problems.

Diabetes Mellitus Type II: An acquired form of diabetes that is defined by insulin resistance and high blood sugar levels caused by poor nutrition and lack of exercise. Recent research exposed that insulin resistance is actually a defense mechanism to prevent oxidative damage associated with over-nutrition.

Electrochemical gradient: A difference of electrical charge across a membrane.

Electrons: A constituent of atoms that holds a negative charge.

Electron Transport Chain: The pathway that humans rely on for generating ATP (chemical energy). Without the electron transport chain, we would need to rely on glycolysis for energy production, and would need to eat about half our weight in sugar each day. In the electron transport chain, electrons are passed from one enzyme complex to the next, with the final electron acceptor being molecular oxygen. With each transfer, protons are pumped to the other side of a membrane which generates an electrochemical gradient. At the end of the chain, the final enzyme is mechanically driven by allowing a flow-back of protons. The ATP synthase enzyme is the final enzyme, and it has a rotor that spins as the protons flow into the enzyme. The spinning pushes ADP up against a phosphate group and allows for the formation of ATP. The electron transport chain occurs in the inner membrane of the mitochondria.

Enzymes: Proteins that catalyze reactions by lowering the amount of energy needed for a reaction to occur. If the reactions that take place in our bodies were to be repeated in the laboratory without the use of enzymes, many of them would require extremely high heat–energy. Enzymes are very efficient, produce no waste, and keep us alive.

Insulin: A hormone produced in pancreas that is responsible for regulating metabolism. The presence of insulin stimulates the transfer of glucose from the blood into the cell to be used for ATP synthesis. In the absence of insulin, glucagon (another enzyme) converts fat into energy. So with insulin, blood sugar is used for energy and without it, we burn fat.

Insulin Resistance: A defense mechanism to protect the mitochondria from oxidative damage. Insulin resistance means that even though insulin is present, blood sugar is not used for metabolism. Blood sugar levels continue to rise as if no insulin is present. Type II diabetes is marked by insulin resistance.

Mitochondria: An intracellular organelle typically referred to as the powerhouse of the cell. This is where we generate most of our energy–through the electron transport chain.

Over-nutrition: Flooding the body with fats and sugars when ATP stores are not being utilized. In other words, eating more calories than are being used.

Polysaccharides: Long chains of sugars. They can be complex and branched, or straight and comprised of one or more type of sugar.

Protons: A constituent of atoms that holds a positive charge.

Reactive Oxygen Species: Reactive molecules that can cause damage to our cells. Oxidative damage is thought by some to be the cause of aging. Superoxides and hydrogen peroxide are examples of reactive oxygen species.

Superoxide Dismutase: An enzyme that can convert highly reactive superoxides into hydrogen peroxide and oxygen. The hydrogen peroxide is then catalyzed further by other enzymes to convert it to water. Superoxide dismutase is an extremely important antioxidant molecule that prevents superoxides from damaging our cells.


A mushroom a day may keep the doctor away. The active ingredients in a Asian mushroom can change bacteria in your stomach for the better, researchers have found. By altering gut bacteria, the Reishi mushroom (Ganoderma lucidum) prevents and reverses symptoms of obesity in mice, including weight gain and insulin resistance.

“Mice kept on a high-fat diet gained up to 25 percent more than mice kept on the same diet with extracts from the Reishi mushroom,” said David Ojcius, a microbiologist at the University of the Pacific School of Dentistry in San Francisco who participated in the study, published Tuesday in the journal Nature Communications. Consumption of Reishi mushroom extract with high-fat food prevented the development of fat tissue, gut inflammation and buildup of harmful bacteria in the bloodstream — all symptoms of obesity in both mice and humans.

Ojcius and colleagues from Chang Gung University and Chang Gung Biotechnology in Taiwan treated mice kept on a high-fat diet with various compounds from Reishi mushrooms, called polysaccharides, to see which ingredient played the biggest role. The ratio of two different types of gut bacteria, firmicutes and bacteroidetes, can indicate gut health, Ojcius said. In this case, a subset of the polysaccharides from the Reishi mushroom altered the bacterial ratio in favor of a healthier gut.

If the Reishi mushroom works by changing gut bacteria, then could introducing healthier bacteria into the stomach be enough to save a fat mouse?

Only the poop can tell.

Doctors have been known to use fecal transplants to alter the gut bacteria of patients with a variety of metabolic disorders, such as Crohn’s disease. Ojcius and collaborators transplanted fecal matter from mice that were fed high-fat diets “seasoned” with Reishi mushroom into already obese mice. These transplants reduced obesity symptoms more than ones from mice kept on a high-fat diet without Reishi seasoning.

The findings in this study suggest that Reishi can promote stomach health in people already experiencing symptoms of obesity, Ojcius said.

But don’t rush to buy out mushroom markets just yet. Reishi extract only helped to slim fat mice; it doesn’t have a strong effect on mice eating regular chow. Having a healthy gut is what prevents metabolic disease, said Ojcius, as evidenced by the observation that fecal transplants from healthy, lean mice, regardless of Reishi mushroom consumption, also reduced body weight in obese mice.

The technology to identify multiple bacteria in a stool sample has emerged only within the last decade. As we know more about the gut’s role in health, Ojcius said, technology that analyzes poop could help doctors or patients monitor gut bacteria and prevent oncoming issues.

Exercise, overall diet and genetics also help define the body’s internal bacteria, Ojcius points out.

Reishi, like many other natural medicinal products, isn’t regulated by the Food and Drug Administration. Because anyone can sell Reishi extract, Ojcius suggests doing research before purchasing.


Background: Reishi (Ganoderma lucidum) is a well-known and popular edible mushroom eaten as vegetables all over the world. It has been used as alternative medicine for long years in China, Korea, Japan, Malaysia, and in eastern Russia. It is reported to exhibit a number of medicinal properties including antitumor, antioxidant, immunomodulating, anti-inflammatory, hepatoprotective, and hypoglycemic activities due to the presence of bioactive polysaccharide. Glucocorticoids, prescribed for the treatment of arthritis to protect inflammation and reduce pain, can induce hyperglycemia or aggravate the hyperglycemic condition reaching to very high glucose levels in diabetic patients. However, no report has been published for its activity on glucocorticoid-induced diabetes. 

Objective: To investigate the effect of Ganoderma lucidum on alloxan- and glucocorticoid- induced diabetes in LongEvans rats.   

Methods: Alloxan monohydrate (150 mg/kg) was intraperitoneally administered to Long-Evans rats as a single dose. The same volume of normal saline was injected to control rats. Three days after alloxan injection, rats with plasma glucose levels higher than 12 mmoL /L were considered as diabetic and they were included in the study. Reishi mushroom was collected from the Mushroom Development Institute, Ministry of Agriculture, Savar, Dhaka, Bangladesh, where it was identified by a Taxonomist. Petroleum ether extract (PEE) Methanol extract (ME) were prepared by maceration and distillation techniques. The extracts were orally administered once in a day at doses of 200, 400, 600 and 800 mg/kg, respectively for 7 days. Metformin (150 mg/kg) was orally administered as a standard antidiabetic drug. Glucose levels were measured at 0 and 7th days of treatment. The rats were allowed to rest for 1 week without treatment. The animals were again injected with dexamethasone (2 mg/kg) through intra-muscular route for 3 days and glucose levels were monitored regularly. Rats were then further treated with PEE and ME and metformin for another 7 days and glucose levels were determined at 0 and 7th days of treatment. 

Results: The PEE and ME of Reishi mushroom dose-dependently reduced the plasma glucose levels in alloxan-and steroid-induced fasting diabetic rats. The maximum reduction of fasting plasma glucose levels observed by PEE (800 mg/kg) and ME (800 mg/kg) were 55.57% and 36.01% in alloxan-induced and 51.41% and 32.02% in steroid-induced diabetic rats, respectively. Whereas, metformin (150 mg/kg) resulted in the diminution of fasting blood glucose levels by 60.02 and 51.12% in the alloxan- induced and steroid-induced diabetic rats, respectively. Both the PEE (800 mg/kg) and ME (800 mg/kg) significantly   augmented plasma insulin levels (***P < 0.001 and **P < 0.01) and reduced HbA1c (**P < 0.01 and *P < 0.05) in alloxan-and steroid-induced diabetic rats. Besides, treatment of diabetic rats with PEE (800 mg/kg) and ME (800 mg/kg) controlled the 2-h post prandial elevated glucose levels in blood plasma. The same dose of the extracts also significantly reduced the levels of total cholesterol (TC) (***P < 0.001 and ***P < 0.01), triglyceride (TG) (***P < 0.001 and **P < 0.01) and low-density lipoprotein-cholesterol (LDL-c) (***P < 0.001 and ***P < 0.001), as well as increased the level of high density lipoprotein cholesterol (HDL-c) (**P < 0.01 and **P < 0.01, respectively).

Conclusion: Our study demonstrated that edible mushrooms-Reishi has antihyperglycemic, insulin-sensitivity, and hyperlipidaemic activity against both alloxan- and corticosteroid-induced diabetes rats. The bioactive chemicals responsible for those activities are most probably the polysaccharides available in the mushroom. Thus, usage of Reishi mushrooms as vegetables or as extract will be beneficial for the management of diabetes.

Keywords: Antihyperglycemic, antidiabetic, insulin-sensitizer, anti-hyperlipidemic, Gano mushroom, Reishi mushroom, Ganoderma lucidum, alloxan-induced diabetes, Steroid induced diabetes, Glycated haemolgobin (HbA1c), Oral glucose tolerance test (OGTT), Hyperlipidemia

Potential benefits of reishi in the fight against diabetes

Ganoderma lucidum has antioxidant properties when ingested as a dietary supplement. Reishi also may have a therapeutic effect on insulin resistance; reishi extracts operate on a wide variety of mechanisms to lower blood glucose.

In this study, reishi inhibited (prevented) alpha-glucosidase enzyme (which is the main enzyme responsible for the cleavage of starch into sugars) activity. This inhibition may prevent the postprandial sharp spike in blood sugar which can be dangerous, especially for older people. By inhibiting the activity of the enzyme carbohydrates are not absorbed at the pace which would damage the blood vessels (little bit same way as the diabetes drug Glucobay which prevents the same enzyme activity in the gut). Read more scientific facts about interaction of reishi with glucose metabolism.



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