By Richard Restak, MD, The George Washington University School of Medicine and Health Sciences

Edited by Kate Findley and proofread by Angela Shoemaker, The Great Courses Daily

Scientists have discovered what they believe is the key to preventing memory decline associated with Alzheimer’s. Dr. Restak explains.

What Is Cognitive Reserve?

By challenging your brain to learn new information throughout your life, you build up what neuroscientists refer to as cognitive reserve. Research shows that this works the same way as planning for retirement by building up monetary reserves. You improve your cognitive capacity in later years by acquiring education and knowledge throughout your life and feeding your curiosity.

We came to appreciate cognitive reserve in the late 1980s, when pathologists came upon an unexpected finding in the brains of elderly people. They found distinguishing hallmarks of Alzheimer’s disease during the autopsy of the brains of people who had not shown the outward signs of the disease during their lifetime. 

Up to a quarter of neurons in the cortex were reduced to dense, tangled bundles of clusters of degenerating nerve endings enclosing a smudged central core. In 1906, Alois Alzheimer identified these plaques and tangles as hallmarks of a dementing disease.

While Alzheimer’s disease primarily involves memory, the symptoms can include many other cognitive processes. Today, Alzheimer’s disease is the most feared neuropsychiatric illness in the world. 

We hear about it every day, read about it in newspapers, and see it spoken of in television shows. While memory lapses at any age raise fears of Alzheimer’s disease, in most cases, such fears are exaggerated. 

Understanding Alzheimer’s

For example, suppose you drive to the mall to do some shopping. You have something particular in mind that you want to get. After parking your car, you go into the mall.

You shop at several stores, and maybe you even have lunch there. Then you leave the mall, and you can’t remember where you parked your car. 

In this case, stress and inattention are the causes of this inability to remember. It’s not memory loss as such, because you were focusing on shopping, not parking.

Memory impairment in Alzheimer’s disease is much more extreme. If you had Alzheimer’s or Incipient Alzheimer’s, you wouldn’t recall whether you drove to the mall or whether someone brought you there. 

The brain defect with Alzheimer’s is the accumulation of debris in the brain. Think of discarded items crammed into an already crowded attic. 

The tangles look like twisted railroad tracks and are made from tau inside the neurons. The plaques look like gummy globs of material outside the neuron. 

They consist of a central dark core surrounded by a darker rim. With increasing accumulation of debris, nerve cell communication is disrupted. The nerve cells shrink, die, and eventually disappear.

In 1984, neuroscientists discovered that the plaque is composed of a protein called beta-amyloid. Many researchers today believe that beta-amyloid is the hallmark of Alzheimer’s disease. It’s also the key to understanding it. 

Alzheimer’s and Cognitive Reserve

Thus, pathologists began to wonder what was going on when they discovered these Alzheimer’s changes in the brains of a coterie of deceased elderly who had functioned normally during their last years. Curious, the researchers investigated the lives of these exceptions. 

They discovered a common trait—increased levels of education. People with more education were less likely to have been diagnosed with Alzheimer’s disease during their lifetime. 

It didn’t seem to matter what the subject matter was; they could be studying physics or history. What is the explanation for this association? 

Dr. Restak believes that education makes for a more efficient use of brain networks. The more educated you are, the more efficiently the brain works. This results in a greater ability to withstand the so far unidentified cause or causes of Alzheimer’s disease. 

Cognitive reserve is the term coined by neuroscientists for this ability of the brain to function normally despite the inroads of Alzheimer’s disease. Keep in mind that while education is usually formal, it doesn’t have to involve traditional academic subjects. 

Embracing Informal Education

“About 10 years ago, I was in Egypt on a trip with some friends,” Dr. Restak said. “We had an Egyptologist with us, a small group of people—about 15 people. Over the course of a couple of days, it became clear that one of the members of the group, a retired food retailer, knew just about as much about Egypt as the Egyptologist.”

Dr. Restak asked him how he learned all the information, and the man replied that he first read about Egypt when he was a kid. He continued to read about it, attended lectures and movies, and watched specials on television about it. 

What he had done is take an obsession and turn it into a lifetime of self education. Art Buchwald is another example of this. 

Art attended two years of college, yet he had an international reputation as a syndicated columnist and wrote more than 50 books. Therefore, to build up your cognitive reserve, you don’t need formal education—only a passion for learning.

Dr. Richard Restak is Clinical Professor of Neurology at The George Washington University School of Medicine and Health Sciences. He earned his MD from Georgetown University School of Medicine. Professor Restak also maintains an active private practice in neurology and neuropsychiatry in Washington, D.C.

This article was edited by Kate Findley, Writer for The Great Courses Daily, and proofread by Angela Shoemaker, Proofreader and Copy Editor for The Great Courses Daily.