Unlike Bell's palsy, it is difficult to demonstrate methylcobalamin's rapid results when protecting against aging-related disorders. On the other hand, the mechanisms of action of methylcobalamin, however, are intriguing.
One cause of brain cell death is glutamate toxicity. Brain cells use glutamate as a neurotransmitter, but unfortunately glutamate is a double-edged sword in that it can also kill aging brain cells. The release of glutamate from the synapses is a usual means by which neurons communicate with each other.
Effective communication means controlled release of glutamate at the right time to the right cells, but when glutamate is released in excessive amounts, intercellular communication ceases. The flood of glutamate onto the receiving neurons drives them into hyperactivity, and the excessive activity leads to cellular degradation. The Life Extension Foundation has never recommended glutamine supplements for healthy people because of concern about glutamine-induced brain cell damage.
The good news is that it may now be possible to protect brain cells against glutamate toxicity by taking methylcobalamin supplements. In a study in the European Journal of Pharmacology (1993 Sep.7;7;241 (1):1-6), it was shown that methylcobalamin protected against glutamate-, aspartate- and nitroprusside- induced neurotoxicity in rat cortical neurons.
This study also showed that S-adenosylmethionine (SAMe) protected against neurotoxicity. In a study in Investigational Ophthalmology Visual Sciences (1997 Apr; 38(5):848-854), a combination of methylcobalamin and SAMe was used to protect against retinal brain-cell toxicity caused by glutamate and nitroprusside.
Researchers concluded that methylcobalamin protects against neurotoxicity by enhancing brain cell methylation. The Life Extension Foundation previously has recommended methylation-enhancing therapies such as vitamin B6, vitamin B12, folic acid and TMG (trimethylglycine) to protect against heart disease, stroke and other aging-related diseases.
The scientists who conducted the methylcobalamin studies emphasize that ongoing intake of methylcobalamin is necessary to protect against neurotoxicity. Thus, for methylcobalamin to be effective in protecting against neurological disease, daily supplementation may be required.
An appropriate dose to protect against neurological aging might be 1 to 5 mg a day taken under the tongue.