Mushrooms – Potential Health Benefits

By Paul E. Lemanski, MD, MS, FACP

Editor’s Note: This is the 128th in a series on optimal diet and lifestyle to help prevent and treat disease. Any planned change in diet, exercise or treatment should be discussed with and approved by your personal physician before implementation. The help of a registered dietitian in the implementation of dietary changes is strongly recommended.

Medicines are a mainstay of American life and the healthcare system not only because they are perceived to work by the individuals taking them, but also because their benefit may be shown by the objective assessment of scientific study. Clinical research trials have shown that some of the medicines of Western science may reduce the risk of Type 2 diabetes, heart attacks, strokes, cardiovascular death and even some cancers.

In the first 127 installments of the Non-Medicated Life, a healthy diet and lifestyle have been shown to accomplish naturally for the majority of individuals most of the benefits of medications in the prevention of the chronic medical conditions mentioned above. With respect to a healthy diet this column has championed a predominantly whole foods, plant-based diet. Such a diet includes diverse fruits and vegetables including mushrooms. This article reviews the emerging evidence for the potential health benefits of mushrooms and may convince you to more frequently include them in your diet. 

Mushrooms are technically not a vegetable (kingdom Plantae) but rather belong to the kingdom Fungi and thus are biochemically distinct from both plants and animals. As such they lack leaves, roots, seeds, and chlorophyll and do not perform photosynthesis. The energy for growth comes from absorbing energy and nutrients from the surrounding environment by feeding on dead or decaying organic matter (saprotrophic), by entering into a mutually beneficial partnership with other organism exchanging certain nutrients for sugar (mutualistic), or by absorbing nutrients from living hosts (parasitic). Their specific health benefits derive from a unique combination of high concentrations of vitamins and minerals, and unique fibers, bioactive compounds, and antioxidants that are distinctly uncommon in other plant or animal foods.

This unique biochemistry of mushrooms has been shown to support cardiovascular protection, improved metabolic markers, anti-inflammatory and antioxidant effects, enhanced immune function (that may reduce risk for infection and cancer), and improved vitamin D levels, when consumed regularly as part of a balanced diet. This article will provide evidence for each of these in turn.

Randomized controlled clinical trials suggests that mushrooms provide cardiovascular and metabolic protection via several mechanisms. Mushrooms contain high concentrations of the amino acid ergothioneine, the sterol ergosterol, and the polysaccharide beta-glucan. A 2026 review found that consuming mushrooms consistently decreased triglycerides and glucose. Diabetic patients consuming, in particular, oyster mushrooms evidenced significant reductions in both systolic and diastolic blood pressure, blood glucose, as well as total cholesterol and triglycerides.

Mushroom polysaccharides, especially beta-1,3-glucans, enhance cell mediated immune response. In one randomized clinical trial in young, healthy adults daily consumption of 5-10 grams/day of Shitake mushrooms (only one medium sized mushroom) over four weeks resulted in a 60% increase in immune T cell proliferation, a two-fold increase in natural killer T cell proliferation, and improved T cell activation. (T cells are used by the immune system to help recognize bacteria and viruses as well as kill them directly). Additionally, the study showed an increase in salivary IgA (immunoglobulin A). IgA lines the gut and respiratory tree and helps protect the gastrointestinal and respiratory tracts from infection. This study also showed a reduction in C-Reactive Protein a potent marker of inflammation.

It is thought that such a reduction in inflammation as well as enhanced immune response may account for the substantial reduction in cancer noted in some observational studies. As little as 18 grams of mushrooms a day (two medium sized mushrooms) resulted in a substantial reduction in cancer, most evident with breast cancer. Other experimental data indicates that the polysaccharides and polyphenols in mushrooms can effect cell cycle regulation (helping slow or stop growth), angiogenesis (growth of the blood vessels that feed tumors), and apoptosis (programmed cancer cell death).

The beta-glucans in mushrooms also reach the colon largely undigested, providing the gut microbiome with prebiotics that help maintain gut bacterial diversity, essential to better digestive function, and improved intestinal wall barrier integrity. These prebiotics are essential to the production of the short chain fatty acids involved in controlling glucose absorption of the subsequent meal, the so called “second meal effect.”

Mushrooms are unique in their ability to synthesize vitamin D and are one of the few non-animal sources of the vitamin. Ultraviolet exposed mushrooms can actually meet the daily requirement of vitamin D. Vitamin D supports calcium absorption for adequate bone mineralization and the avoidance of osteoporosis. Moreover, vitamin D receptors exist on the surface of white blood cells that fight bacterial infection and may by this mechanism also improve immune function. Preliminary research on lion’s mane mushroom suggest possible neuro-protective effects including promotion of nerve growth and protection against neurodegenerative disease, which may in part be related to its effects on vitamin D.

Finally, mushrooms offer potent nutrient density supplying a plethora of micronutrients while minimally affecting total daily calories. They are very low in calories, fat, sugar, and sodium, yet supply – proportional to weight – a significant amount of protein, fiber, and B vitamins. They provide a potent umami flavor with a high volume food that is at the same time low calories and sodium allowing satiety to be reached at a lower total caloric intake. Indeed, portabella mushrooms are a very acceptable substitute for meat for those seeking a low calorie “hamburger.”

In summary, mushrooms consumption is associated with wide range of health benefits including cardiovascular, metabolic, anti-inflammatory, and immunomodulatory. A very modest mushroom intake of 10-18 grams/day (one or two medium sized mushrooms/day) may provide significant immune system protection and even cancer reduction. Mushrooms are easy to prepare and incorporate into multiple dishes and provide strong umami flavor at a low sodium and caloric intake. While the science behind them is somewhat technical and may not be completely understood, there is a simple take away – EAT MORE MUSHROOMS.

Paul E. Lemanski, MD, MS, FACP (plemanski3@gmail.com) is a board-certified internist practicing internal medicine and lifestyle medicine in Albany, NY. Paul has a master’s degree in human nutrition, he’s an assistant clinical professor of medicine at Albany Medical College, and a fellow of the American College of Physicians.