Pass Grandma the mushrooms: Study finds reishi extract improves immune function in older women

Reishi (Ganoderma lucidum) is a type of mushroom that enjoys a long history in Traditional Chinese Medicine (TCM). Written records document medicinal use of reishi in China well over 2,000 years ago. In China, this mushroom is called lingzhi.

Reishi mushrooms are characterized by their distinctive reddish-brown cap and woody texture. In fact, reishi actually grows out of decaying wood. The mushroom is found in the wild; however, due to high demand for medicinal and supplement use, it is mostly cultivated in modern high-volume farms.

Reishi is often referred to as the “mushroom of immortality” due to its legendary status and wide use in traditional healing.

China connection

While reishi is used for a wide array of health conditions in TCM, it is perhaps most recognized for energy and immune benefits.

Today the mushroom is prescribed as medicine in various forms—whole mushroom, extracts and tinctures—in pharmacies and TCM hospitals all across China. Tens of millions of people utilize it as medicine or supplement on a daily basis.

Though recognized for its long history in Eastern tradition, reishi is far less utilized in Western/modern medicine.

Acknowledging that in the Western world “studies on the physiological effects of Ganoderma lucidum dry extract food supplements are few,” researchers in Brazil set out to investigate the celebrated mushroom’s immune benefit on older women.

Even though the study was small—involving just 39 women—the researchers ultimately documented results that are inline with the TCM claims.

According to the findings of the study, 2000 mg per day of reishi mushroom helped improve the immune system of the female test participants by “modulating T lymphocyte function.”

Lymphocytes are a type of white blood cell that help the immune system fight disease and infection. T lymphocyte cells can kill infected cells, activate other immune cells, produce cytokines, and regulate the immune response.

Study details

To conduct the study women between the ages of 60 and 80 were divided into two groups. The test group consumed 2,000 mg of reishi for eight weeks; the other consumed a placebo. Blood and urine were collected and analyzed before and after the eight-week period.

To calculate immune benefits of the reishi supplementing, researchers analyzed body mass index, lymphocytes and gene expression.

Body mass composition did not change in either group; however, at the end of the supplementation period, certain gene expressions—known scientifically as IL6 and TNF alpha—were higher for participants in the supplement group.

The IL-2 gene expression was also elevated in the supplement group after eight weeks—a status that suggests the cytokine may mediate a regulatory mechanism.

“Our study demonstrates that the supplementing with 2,000 mg/day of whole Ganoderma lucidum extract for eight weeks positively regulates the expression of genes associated with activating Th1, Th2 and Th17 cell profiles,” the researchers wrote in the study conclusions. “The shift toward a Th2 profile suggests a predominance of an anti-inflammatory response.”

The study’s conclusions were published in the British Journal of Nutrition in May, 2024.

The reason for conducting the study on older people is basic: As people age, they experience immunosenescence—or, simply, a decrease in immune function.

This is especially relevant with T lymphocytes. The function, activation and differentiation of T lymphocytes has been shown to be impaired in the elderly, leading to an immune imbalance.