Ganoderma lucidum (GL) fungus, referred to as reishi or lingzhi in Asia, improves testosterone levels, sexual function, and fertilization rates among middle-aged male mice.
Reproductive capabilities wane as we grow older. By age 50, male humans produce ~30% less sperm per day than younger counterparts, which often results in reproductive failure — a hampered ability to produce offspring. Along those lines, levels of the key hormone in maintaining normal reproductive and sexual function, testosterone, decline approximately 1% per year beginning at age 40. As such, researchers continuously seek new strategies to boost testosterone and prevent male reproductive aging.
Published in Nutrients, Qin and colleagues from Peking Union Medical College in China show that GL fungus extract treatments significantly increase testosterone in middle-aged male mice. Consuming the fungal extracts also doubled the number of times middle-aged males pursued females in a 20-minute period, suggesting the fungus increases sexual function and libido. Moreover, the middle-aged males that consumed GL extract produced about 37% more offspring. The study’s findings suggest that treating with an extract from the fungus, known for centuries in Asia as an invigorating and energy-boosting dietary supplement, can prevent reproductive aging in males.
To find whether GL affects levels of the pro-sexual functioning hormone testosterone, Qin and colleagues measured testosterone levels in males that consumed extracts from the fungus. Fourteen-month-old males (the equivalent of about 50 years in humans) had significantly higher testosterone levels than their age-matched counterparts. Moreover, their testosterone levels were comparable to those of younger, nine-month-old males (the equivalent of about 40 years old for humans). These findings suggest that consuming GL extract can increase testosterone levels in middle-aged males, restoring their levels to those of younger males.
Since testosterone drives improved sexual function, Qin and colleagues measured how often middle-aged males fed GL extract pursued females over a 20-minute period, an indicator of functional sexual behavior. The China-based researchers found that the middle-aged, 11.5-month-old mice (equivalent to about 44 years old in humans) pursued females at over double the frequency of those who didn’t consume the fungal extract. These data suggest that increasing testosterone levels with GL extract can also improve sexual behavior, likely by increasing libido.
Because testosterone also drives fertility — the ability to produce offspring — Qin and colleagues measured the reproductive success of middle-aged, 11.5-month-old males. They found that the litter sizes and birth ratios — the number of offspring that didn’t perish out of the total number of offspring — from fungal extract-consuming males increased substantially compared to age-matched counterparts. The average litter size through the production of four litters was ~37% higher for GL extract-consuming males, also. These results suggest that GL enhances middle-aged males’ reproductive capabilities.
The beneficial health effects of GL were first recorded in China by Shen Nong in the book Materia Medica, earlier than 100 BC (Before Christ). In the book, Shen Nong described GL as being capable of increasing energy and vitality, along with prolonging lifespan. Interestingly, although residents of Asia have known about this fungus for centuries, this is the first known study to show that it works against male reproductive aging. Limitations to the study include that only six mice were used per experimental group, a low number that makes statistical comparisons difficult. Future studies will be necessary to find whether GL extracts help against male reproductive aging in humans. A month’s supply of GL capsules or droplets to mix with tea can be purchased for $60 to $110.
Model: C57BL/6J mice
Dosage: 0.6 g/kg per day of Ganoderma lucidum spore powder and spore oil solution for 2.5 months