Cognitive Reserve - What Is It?

One of the concepts discussed in recent Alzheimer's disease research is cognitive reserve. If you have read about cognitive reserve, you may have wondered what it is. And what does it have to do with Alzheimer's disease and other neuropathologies (diseases of the nervous system)? Hopefully, this article can help you understand cognitive reserve a little better.

Where did the idea of cognitive reserve start?

The idea of cognitive reserve started when doctors noticed that not everyone with Alzheimer's disease lost the same amount of ability to function.

The doctors wanted to know why 2 people with the same disease could have very different outcomes. They began to study differences in people's brains. Cognitive reserve is the concept they came up with to explain why some people's brains seemed to be able to continue to function well despite age and disease.¹

What is cognitive reserve?

Cognitive reserve is not precisely defined right now. But doctors are working to decide on a better definition to help with future research. Whole articles have been written to help scientists agree on the definition of cognitive reserve.²

This was the definition that 1 group of doctors agreed upon: "The term CR [cognitive reserve] refers to the adaptability (i.e., efficiency, capacity, flexibility) of cognitive processes that help to explain differential susceptibility of cognitive abilities or day-to-day function to brain aging, pathology or insult." This is another way of saying that cognitive reserve is how capable a brain is of staying healthy and flexible as it deals with the changes caused by:^1,2

1. Age
2. Injury
3. Disease

What determines someone's cognitive reserve?

Doctors think that many factors can influence cognitive reserve, including:³

• Education level
• Social interaction and engagement
• Exercise
• Having a job that is challenging but fulfilling

There is no test to measure cognitive reserve directly. Doctors look at a person's overall health and life experiences to help them understand that person's cognitive reserve.²

Cognitive reserve can change

Doctors also know that cognitive reserve can change. While some factors that affect cognitive reserve cannot be changed, like genetics or early childhood experiences, many can be. Doctors think that improving the quality of any of these factors can increase cognitive reserve at any time during a person's life:^2,4

• Sleep
• Education
• Exercise

Life enrichment activities, such as volunteering and hobbies, can also potentially improve cognitive reserve.

Cognitive reserve and Alzheimer's disease

So now that you understand cognitive reserve a little better, you're probably wondering how it impacts Alzheimer's disease. Doctors think that cognitive reserve has 2 main influences on Alzheimer's disease.

The first way cognitive reserve affects Alzheimer's disease is called resistance. Resistance is how cognitive reserve protects the brain from an initial Alzheimer's disease diagnosis. An example is a person who shows Alzheimer's disease on brain images but has few or no symptoms.^1,4

The second way cognitive reserve affects Alzheimer's disease is called resilience. Resilience is how the brain copes with the damage that Alzheimer's disease causes. Resilience is seen in people whose Alzheimer's disease does not progress as fast as their doctors expect it to.^1,4

The jury is still out

Cognitive reserve is a flexible concept. Until there are better tools to measure cognitive reserve, the concept is open to interpretation. Even doctors are still working to understand and define it and how it affects Alzheimer's disease and other neuropathologies.

Cognitive reserve continues to be researched. One day, this research may lead to new ways to treat or prevent Alzheimer's disease.