Description:
 

GLP-1, short for glucagon-like peptide-1 is a short, naturally occurring peptide hormone just 30-31 amino acids in length. Its primary physiologic function is to lower blood sugar levels by naturally enhancing insuline secretion. It also plays roles in protection beta cell insuline stores by promoting insuline gene transcription and has been linked with neurotrophic effects in the brain and central nervous system. In the GI system, GLP-1 has been shown to significantly decrease appetite by delaying gastric emptying and reducing intestinal motility. Preliminary research has shown impacts of GLP-1 in the heart, fat, muscles, bones, liver, lungs, and kidneys as well.

The primary focus of GLP-1 research has been in the realm of diabetes treatment/prevention as well as appetite suppression. Secondary research focuses on the potential cardiovascular benefits of the peptide. More recent, and thus less robust, research focuses on the ability of GLP-1 to stave off neurodegenerative disease. Though this latter area of research is newest, it is also the fast-growing area of GLP-1 study now that the peptide has been revealed to slow or prevent the accumulation of amyloid beta plaques in the setting of Alzheimer’s disease.

Application:
 

There is some evidence to suggest that GLP-1 can improve learning and help to protect neurons against neurodegenerative diseases such as Alzheimer’s disease. In one study, GLP-1 was shown to enhance associative and spatial learning in mice and even to improve learning deficits in mice with specific gene defects. In rats that over-express the GLP-1 receptor in certain regions of the brain, learning and memory are both significantly better than in their normal controls

Interestingly, GLP-1 and its analogue exendin-4 have been shown in mouse models to reduce levels of amyloid-beta in the brain as well as the beta-amyloid precursor protein found in neurons. Amyloid beta is the primary component of the plaques observed in Alzheimer’s disease, plaques which, while not necessarily known to be causative, are associated with the severity of the disease. It remains to be seen if preventing amyloid beta accumulation can protect against the effects of Alzheimer’s disease, but this research is, at the very least, a tantalizing clue as to how scientists my intervene in the progression of mild cognitive impairment to full Alzheimer.