Just because certain people have suffered some mental decline doesn’t mean Alzheimer’s cannot he stopped from worsening. 

In hopes of preventing the disease, a pair of studies are working on targeting extremely early brain changes, while memory and thinking skills remain intact. 

The only studies of its type to enroll healthy older people, participants are currently being registered by clinics throughout the United States, along with other countries. 

“The excitement in the Alzheimer’s field right now is prevention,” said Dr. Eric Reiman, executive director of the Banner Alzheimer’s Institute in Phoenix, which is leading the work. 

Thus far, a drug has yet to be found that can alter the progression of Alzheimer’s, which is the most common form of dementia. A recent report found that 146 attempts have failed over the last decade. 

“What we have been learning, painfully, is that if we really want to come up with therapies that will modify the disease, we need to start very, very, very early,” said Dr. Eliezer Masliah, neuroscience chief at the National Institute on Aging. 

Masliah’s agency is funding studies for prevention with the Alzheimer’s Association, several foundations and the makers of two experimental drugs currently being tested, Novartis and Amgen.

The goal is to attempt to block early stages of plaque formation in the brains of healthy people who exhibit no dementia systems, but are at a higher risk as a result of their age and a gene that increases the likelihood. 

Interested participants must first join GeneMatch, a confidential registry of folks interested in volunteering for various Alzheimer’s studies who are ages 55 to 75 and have not been diagnosed with any mental decline. 

Applicants are also checked for the APOE4 gene, which doesn’t destine someone to develop Alzheimer’s but raises that risk. Approximately one in four people have one copy of the gene and about 2 percent have two copies, one from each parent. 

Over 70,000 people have signed up since the registry was started three years ago. 

“Most of them have been touched by the disease personally,” either by having a family member or close friend with it, said Banner study leader Jessica Langbaum.

Langbaum’s 67-year-old mother, Ivy Segal, gave a DNA sample through a cheek swab and joined the registry in August. Her father was a patient at Banner and died of Alzheimer’s in 2011 at age 87. Witnessing him go from a mild-mannered man whose smile could light up a room to what he was like when he lost his battle to the disease was devastating, she said.

Possessing a profile in GeneMatch doesn’t guarantee people will find out if they have a gene as those with and without it may be contacted for various studies. To be in the prevention study, participants must agree to learn their APOE4 status and must have at least one copy of the gene. 

Participants will receive periodic brain scans, along with memory and thinking tests every six months. They are also given either experimental drugs or placebo versions for several years.

One study that is enrolling people carrying two copies of the gene is giving participants either shots every few months or a drug to help the immune system clear plaque from the brain or daily pills of a drug intended to prevent first steps of plaque formation, or placebo versions of these experimental treatments.

The remaining study consists of those who either have two copies of APOE4 or one copy of the gene plus evidence on brain scans of plaque starting to build. They will receive one of two doses of the drug to prevent plaque formation or placebo pills.

Larry Rebenack, 71, of the Phoenix suburb of Surprise, Arizona, joined GeneMatch in August.

“I have a lot of friends and acquaintances I’ve seen deteriorate,” including one who started blowing through stop signs on a route to a golf course they had safely traveled for years, and another who forgot not only where he had parked his car but even what kind of car it was, Rebenack said. “It’s a disease that takes a little part of you away each day.”

Rebenack has decided to learn whether he has the gene if researchers provide him with an opportunity to find out. 

“It’s like any other piece of information. It helps you plan your life and you owe it to all your loved ones, too.”