A study published last December in the journal Brain Research found that a drug developed to treat Type 2 diabetes may have another important application. Researchers discovered that the drug “significantly reversed memory loss” in mice with Alzheimer’s disease and could be used someday to treat Alzheimer’s in humans.
Alzheimer’s, which is predicted to affect 16 million people by 2050, is the sixth-leading cause of death in the U.S., killing more people than breast cancer and prostate cancer combined, according to the Alzheimer’s Association. The new study was hailed as a possible breakthrough in treatment for the degenerative brain disease. The study’s lead researcher, professor Christian Holscher of Lancaster University in the U.K., said in a release that the treatment “holds clear promise of being developed into a new treatment for chronic neurodegenerative disorders such as Alzheimer’s disease.”
And Dr. Doug Brown, director of research and development at the Alzheimer’s Society, a U.K. organization that partially funded the research, said in a release, “With no new treatments in nearly 15 years, we need to find new ways of tackling Alzheimer’s. It’s imperative that we explore whether drugs developed to treat other conditions can benefit people with Alzheimer’s and other forms of dementia. This approach to research could make it much quicker to get promising new drugs to the people who need them.”
So is this really the breakthrough science has been looking for?
[See: Emerging Treatments for Alzheimer’s Disease.]
Diabetes and Alzheimer’s Links
Heather Snyder, senior director of medical and scientific relations at the Alzheimer’s Association, is hopeful the treatment is a significant development, but she’s not quite ready to pop the champagne. “It’s interesting, but it’s still early” in the research process, she says.
Other diabetes drugs have been shown to help patients with dementia, she points out. There seems to be a connection between the two diseases. Indeed, Type 2 diabetes is a known risk factor for Alzheimer’s and its progression. Impaired insulin function has been linked to cerebral degeneration in the brains of those with Alzheimer’s. “Evidence suggests that the underlying biology with diabetes impacts brain health in later life,” Snyder says.
The brain uses more fuel, in the form of sugars, than any other organ, and there is an overlap in the mechanisms by which the brain and the rest of the body metabolize that fuel, Snyder says. But brain cells are different. “The brain is a tightly controlled organ, and there are protections for what gets in through the blood-brain barrier,” she explains. This natural barrier is a membrane that filters the blood of toxins and other harmful chemicals before it gets to the brain. It also makes it hard to get medications in. “There are many differences in how these pathways are regulated, what they are and how they work. There are still a lot of open questions, a lot we don’t know,” Snyder says.
[See: 9 Habits That May Reduce Your Risk for Developing Alzheimer’s.]
What scientists do know is that some diabetes drugs seem to help. “There are about 300 clinical trials going on now,” Snyder says. They all target different potential causes of dementia, including three hormones that are important in regulating blood-sugar levels, known as GLP-1, GIP and glucagon.
For instance, researchers have studied how drugs that target GLP-1 receptor agonists — chemicals that bond with a particular cell to produce a metabolic response — work on people with Alzheimer’s disease and Parkinson’s disease. GLP-1 drugs are known by such brand names as Victoza, Byetta and Bydureon, and a small study from 2016 found that Alzheimer’s patients who took Victoza (liraglutide) maintained normal glucose metabolism in the brain, while those who took a placebo saw decreased glucose metabolism. This means the drug may help the brain of Alzheimer’s patients process sugars more efficiently and maintain cellular health better. Other studies that are investigating diabetes drugs such as pioglitazone (brand name Actos) and rosiglitazone (Avandia) are in their second or third phases, Snyder says.
The new study is different in that it uses an experimental drug that targets all three of the blood sugar hormones –known as a triple agonist — the first time such a drug has been tested, the researchers claim. The study was performed on mice that were bred to express human mutated genes that cause Alzheimer’s. The mice treated with the drug did better in a maze test that measured learning and memory formation. They also showed increased levels of a brain growth factor that protects nerve cell functioning, reduced amounts of amyloid plaques in the brain that are linked with Alzheimer’s, lower measures of both chronic inflammation and oxidative stress and slower rates of nerve cell loss.
[See: How Music Helps People With Alzheimer’s Disease.]
An Exciting Time
A lot of research still needs to be done before this experimental drug is ready to be tested on humans. The other drugs, though promising, are also a long way from being proved safe and effective treatments for Alzheimer’s or other forms of dementia.
Nevertheless, Snyder and other experts in the field are hopefully optimistic. “All these studies are going forward because they target things we know are important,” she says. “The disease is complex, with many pathways affected.” She compares dementia to cardiovascular disease, in which many factors like blood pressure, cholesterol and blood sugar combine in complex ways. “Drugs might target one pathway or biology, then as we understand more, other drugs may be combined,” she says, much as we now take both statins and antihypertensives to treat the different causes of heart disease. “It is essential to move these studies forward to move to a place where we can think about what to combine.”
For her, these studies make her field “the most exciting it’s ever been. Our understanding has advanced tremendously in the last decade. There is a lot of hope and excitement in the field.”
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Emerging Treatments for Alzheimer’s Disease
9 Habits That May Reduce Your Risk for Developing Alzheimer’s
How Music Helps People With Alzheimer’s Disease
A Diabetes Drug Helps Reverse Memory Loss in Mice With Alzheimer?s Disease. Should We Be Excited? originally appeared on usnews.com
