Alzheimer's is a devastating disease, robbing victims of their memories and the ability to care for themselves. More than 5.5 million Americans are currently living with the disease, which is the most common form of dementia. 

Alzheimer's has no cure, and current medications offer only modest improvement. Scientists around the world, though, are rushing to discover ways of treating current victims and preventing the disease in the future. Here's a breakdown on the most recent research:

• Magnetic therapy to stimulate nerve cells. A non-invasive therapy using magnets could soon be used to treat Alzheimer's disease, say researchers at Canada's McGill University. Transcranial magnetic stimulation (TMS) uses a cap that sends a brief magnetic pulse through the scalp to manipulate activity in the brain.

In a study published in the journal Neuron, researchers found that when TMS delivered magnetic pulses that matched natural brain waves, subjects performed better at auditory memory tasks. They believe that TMS could compensate for the loss of memory caused by Alzheimer's and other neurodegenerative diseases.

• Lasers to reactivate "lost" memories. Scientists believe that memories lost to Alzheimer's disease disappear forever because the amyloid plaques and tau tangles that accumulate in the brain destroy memory-retaining neurons. That may not be the case, however, according to scientists at Columbia University, who suggest that the memories may simply be harder to access.

Two sets of mice — one group was healthy and the other had a condition similar to Alzheimer's —  were exposed to a lemon scent before being subjected to an electrical shock. When they were exposed to the same lemon scent a week later, the normal mice froze after smelling the scent, indicating they anticipated a shock, while only half of the mice with Alzheimer's reacted.

Brain scans indicated that the normal mice accessed memory areas of the brain normally while the Alzheimer's mice accessed the wrong memories. When the memory area of the brain was stimulated with a blue laser, the Alzheimer's mice began to freeze when they smelled the lemon scent, indicating the "lost" memories still existed and could be accessed.

• Blood test to predict Alzheimer's. A study at Washington University School of Medicine in St. Louis found that amyloid beta can be detected in the blood well before symptoms appear. It suggests the potential to identify people with abnormal levels long before current diagnostic methods.

As the brain performs its daily tasks, it continually produces and clears away amyloid beta. Some is released into the blood, and some floats in the cerebrospinal fluid. If it starts building up, though, it forms plaques.

Researchers found that blood levels of a subtype of amyloid beta — amyloid beta 42 — were consistently lower in patients diagnosed with Alzheimer's, meaning that some of the amyloid beta 42 had remained in the brain.

The trial, which drew 20 samples of blood from volunteers over a 24-hour period, accurately classified the patients with Alzheimer's 89 percent of the time. A single blood sample was accurate in 86 percent of patients.

"This is exciting because it could be the basis for a rapid and inexpensive blood screening test to identify people at high risk of developing Alzheimer's disease," said researcher Randall J. Bateman, M.D.

• LED lights to shrink brain plaques. Researchers at the Massachusetts Institute of Technology have used LED lights at a specific frequency to reduce beta amyloid plaques.

The treatment triggers brain waves called gamma oscillations, which researchers found help the brain suppress the production of beta amyloid while stimulating the cells capable of destroying the plaques. The treatment was successful in mice bred to develop Alzheimer's but didn't yet have symptoms.

Researchers used a simple device consisting of a strip of LEDs that could be programmed to flicker at different frequencies. The flickering lights at 40 hertz stimulated the hippocampus, a region of the brain critical in forming and retrieving memories. After one hour of stimulation at 40 hertz, levels of beta amyloid proteins in the hippocampus decreased by 40 to 50 percent.

Researchers say their findings may herald a breakthrough in the understanding and treatment of Alzheimer's, and its potential is enormous if it works in humans because it's so accessible and noninvasive.

Although current medications offer minimal help, doctors may welcome a 2017 Canadian study which compared the safety and effectiveness of the four most widely prescribed drugs to treat moderate to severe Alzheimer's: donepezil, rivastigmine, galantamine or memantine.

They found that donepezil was likely the most effective medication across all aspects measured, including cognition, behavior, and overall health.

Donepezil was also the only cognitive enhancer that reached the minimal clinically important threshold — meaning effects on outcomes were observed clinically, as well as statistically — on the Alzheimer's Disease Assessment cognition scale, making it the likely first choice for those patients and clinicians considering these medications, the authors said.

The study was published in the Journal of the American Geriatrics Society.

More help may soon be on the way. British researchers have announced that a drug developed for Type 2 diabetes significantly reversed memory loss in mice with Alzheimer's. While the drug was unnamed, scientists said it combines three growth factors — GLP-1, GIP, and Glucagon — that act in multiple ways to protect the brain. The study was published in Brain Research.