Science is a gradual, incremental process — medical game-changers start with small discoveries. When it comes to Alzheimer's disease, researchers have struggled to understand the true cause of the memory-stealing condition, but they are continuously learning more that could help pave the way forward to make a difference for patients.
Although the treatment landscape has remained stagnant for many years, disease modifying treatments are starting to become available. Drugs like Aduhelm from Biogen and Eisai promise to clear amyloid plaques from the brain, while newer, potentially more effective, amyloid-targeting candidates are nearing the finish line. Meanwhile, other drug developers are zeroing in on tangles called tau in the brain, which many have believed for decades could be another viable target for improving Alzheimer’s symptoms.
But with no silver bullet available for patients, scientists at research institutions are still working to understand the basic mechanisms of Alzheimer's and, in early preclinical settings, finding unique aspects of the disease that could someday lead to more knowledge of how to prevent, treat or even cure it.
A toast to brain health
Clearing amyloid proteins is theorized to be a major way to prevent memory loss associated with Alzheimer's disease and is the mainstay of several of the closest drugs to market from big biopharma companies like Biogen, Eisai and Eli Lilly. And some chemical compounds from nature could contribute, as well, including extracts from the hops flower, which is used to flavor beer.
Extracts from different kinds of hops used in the brewing process demonstrated antioxidant properties that could help keep the amyloid proteins from collecting between nerve cells in the brain, according to a report from the American Chemical Society. Sorry — simply drinking beer may not be the key, the researchers were quick to point out, but the compounds could someday be used as the basis for new treatments or preventative measures.
An estrogen link
Women are at greater risk of developing Alzheimer's disease, and a recent study could show why. Findings from Scripps Research and MIT demonstrated that women who died from Alzheimer's disease had higher levels of a certain modified immune protein in their brains than men.
The process by which the immune protein — called complement C3 — is modified is a chemical reaction that could trigger the destruction of synapses in the brain, which many scientists believe could lead to the cognitive decline seen in patients with Alzheimer's, according to a release from Scripps. Estrogen has normally protected the brain from these chemical reactions, but when these levels fall during menopause, that protection could go away, resulting in progressing disease.
"Why women are more likely to get Alzheimer's has long been a mystery, but I think our results represent an important piece of the puzzle that mechanistically explains the increased vulnerability of women as they age," said Dr. Stuart Lipton, a clinical neurologist and professor at Scripps Research. Now Lipton and his team are looking at ways to reduce these effects and potentially bring those results to Alzheimer's patients down the road.
Learning from dolphins
Humans might not be the only species to show symptoms of Alzheimer's disease, a new study from three research institutes in Scotland found. In two dolphins and a pilot whale that were considered old for their species, the scientists found heightened levels of beta-amyloid proteins, tau tangles and glial cells — all hallmarks of Alzheimer's in humans that have not been found to occur naturally in animals.
The findings could stem from many different causes, but exploring how these changes in the brains of other mammals develop could help researchers understand how they form in humans.
"If we can determine the likely triggers of this, can we work out ways to treat or prevent it?" said researcher Tara Spires-Jones from the University of Edinburgh in a report from The Guardian.
Not just one disease
A "disease" like Alzheimer's is actually more likely a variety of conditions that arise from different triggers, and scientists from the University of Washington believe that identification of these various kinds of Alzheimer's could lead to better treatment. Shubhabrata Mukherjee, a research assistant professor of medicine at UW and lead author of a new study, said that this could be why some "good" drugs might fail in clinical trials — they haven't been used in the right patients.
The researchers separated patients with late-onset Alzheimer's disease into six cohorts based on cognitive function, and they found that the groups had genetic data that made them biologically distinct. At specific locations in the patients' genomes, they found relationships that showed strong risk factors for cognitive decline.
The research isn't finished yet, said Mukherjee in a release from UW — but finding a way to address each type of the disease could bring the world closer to treatments or a cure.