This week, we are discussing Lions Mane Mushroom, or Hericium Erinaceus, and it is medical applications to Alzheimers disease (AD). Currently, no medications are available on the market to prevent, reverse, or stop the progression of AD. Although several clinical trials are showing promise, scientists are also looking at alternative therapies, such as lions mane, for AD. Lions Mane is a food mushroom that is often consumed without harmful effects in countries such as Japan and China.
It is usually found growing beneath older broadleaf trees and contains Erinacine, a naturally occurring substance that has pharmacological effects on the central nervous system (CNS). There are two forms of Lions Mane which can be consumed; fruit bodies and a mycelium which contains the erinacines. The erinacines are in a group of compounds called the cyathin diterpenoids, and are stimulators of neural growth factor (NGF). NGFs have a supporting role in the CNS, and are crucial for adequate protection of neurons that are alive and developing.
Rats given erinacine A for 3 weeks increased the concentrations of noradrenaline and homovanillic acid in the hippocampus relative to controls, and showed evidence for increased levels of NGF in general, particularly in the dentate gyrus of the hippocampus. The increased levels of noradrenaline and homovanillic acid led to increased alertness and better recall of memories, as well as breakdown of fats and increased levels of blood glucose for promoting increased energy, suggesting erinaceus A contributes to neural and brain health in animal models. In addition, mycelium from H. erinaceus that contains erinacine A, administered orally for 30 days to AD transgenic mice, results in decreased plaque load recruiting and activation relative to controls.
Other structures frequently impaired in AD, such as the hippocampus and locus coerulous, also showed improved function compared with those who were not given the mycelium. A double-blind clinical trial assessed the oral administration of H. erinaceus fruit bodies to older adults showed improvements for subjects with mild cognitive impairment, compared with age-matched controls.
Researchers measured the improvements using the revised Hasegawa Dementia Scale (HDS-R). The H. erinaceus-ingested group increased its scores substantially over the 16-week treatment period, suggesting improvements over the non-H. erinaceus-ingested group. However, when subjects stopped taking H. erinaceus, their scores began to decline, reflecting scores similar to those that were not treated, suggesting a need to continue using.
Several different compounds found in H. erinaceus seem to have protective benefits, such as reducing amyloid plaques, decreasing expression of insulin-degrading enzymes, increasing the release of NGF, and even managing neuropathic pain. While a few are known in the H. erinaceus, many compounds are still being studied, with a few yet to be discovered.
These discoveries, and those that are being made, will hopefully continue to lead the way to therapeutic strategies that can prevent, manage, and slow AD progress. In addition, previous studies and clinical trials have shown Lions Mane and its extracts are safe for human consumption in doses of 3-4 grams daily (although allergies have been noted). If you are interested in this research, we recommend discussing Lions Mane with your primary care doctor for potential cognitive enhancement.