During autopsies back in the 1980s, scientists noticed that some people’s brains showed signs of Alzheimer’s disease despite having no history of memory issues. This was a puzzling observation. After further research, scientists proposed that these individuals had built a “reserve” that allowed their brains to function properly despite the damage caused by Alzheimer’s.
As investigation of these cases continued, scientists identified "modifiable factors" that can contribute to building this reserve in your brain. Based on the data, health professionals came up with recommendations that can help build this reserve. And many of these recommendations overlap with components of Total Force Fitness (TFF)—HPRC’s framework that helps Service Members optimize and sustain their performance and wellness.
Regardless of your age, you can modify your lifestyle and develop habits to help you build this type of reserve. As a Service Member, you face unique mental and physical challenges, and this reserve can help protect your brain health.
What's cognitive reserve
Scientists decided on the term “cognitive reserve" to describe the brain's resilience and capacity to sustain cognitive function despite damage from brain disease, injury, trauma, and aging. But, what does cognition or cognitive mean?
Cognition is your ability to think, learn, focus, solve problems, make decisions, plan, manage information, and control your feelings and behaviors.
In other words, cognitive reserve is about having a more efficient and adaptable brain that mobilizes and uses alternative neural pathways to support all your cognitive functions, even when injury, disease, and aging occurs.
"Brain reserve" is a similar concept. It refers to your brain's structural capacity—brain size, neuron count, gray and white matter volume, number of connections between neurons—to withstand damage and maintain function. Cognitive reserve refers to things associated with how your brain functions, while brain reserve refers to your brain’s structure. When you build both cognitive and brain reserves, your brain can handle more damage before deficits become noticeable.
Another key factor in your ability to sustain cognitive function is “brain maintenance.” It’s linked to how your brain preserves functional and structural integrity over time, especially as you age. While cognitive and brain reserves focus on tolerating or compensating for brain damage, brain maintenance can prevent damage from happening and supports cognitive health over time.
How cognitive reserve can protect your brain
Cognitive reserve has a protective effect against various brain injuries and disorders. When Service Members build cognitive reserve, they can reap many brain health benefits.
Protection against traumatic brain injury (TBI). Cognitive reserve can help protect your brain against all severities of TBI. What does protection from TBI mean?
- Cognitive reserve can help minimize cognitive deficits after TBI and lower the risk of secondary injury.
- It reduces the risk of lasting concussive symptoms such as mood instability and decision making and memory impairment that can happen after uncomplicated mild injuries.
- People who suffer repeated TBIs have increased risk to develop chronic traumatic encephalopathy (CTE), a degenerative brain condition. But, cognitive reserve can delay the onset of CTE symptoms.
- For more severe injuries, higher cognitive reserve increases the chance of a disability-free recovery.
Protection against psychiatric disorders. Cognitive reserve, mood, and sleep are highly interdependent, meaning the quality of one of these factors is likely to affect the quality of the other 2.
- For example, consistently getting the recommended 7–9 hours of sleep helps you build cognitive reserve, which in turn can help protect you from mood disorders. Building cognitive reserve can protect you from mood disorders, such as depression, that often come with cognitive dysfunction.
- Cognitive reserve can also protect against psychological disorders such as schizophrenia.
Protection against neurological disorders. Cognitive reserve can also lessen the severity of symptoms for Alzheimer's disease, Parkinson's disease, multiple sclerosis, and stroke.
Like with the brain autopsies that prompted scientists to investigate this topic, neurodegeneration can occur, but symptoms will take longer to appear or be milder.
How can you build cognitive reserve?
Several factors influence your ability to build cognitive reserve. Some, such as biological sex, genetics, history of chronic diseases, early life experiences, and socioeconomic status, aren’t changeable. Other factors, however, are within your control and are related to your lifestyle choices. As mentioned earlier, many of these factors align with TFF strategies that support your overall health, wellness, and performance.
Exposure to challenges and complex environments. Activities that challenge your brain, such as higher education or demanding occupations, can help you build cognitive reserve. It's important to emphasize that it's never too late to pursue these challenges.
- Higher education later in life can also help you build cognitive reserve. But exposure to challenges isn't limited to formal education. Taking on complex tasks that require learning new skills, problem solving, and critical thinking can also help.
Social activity and engagement. A large and diverse social network and frequent social engagement contact can also boost cognitive reserve.
- Combining social contact with activities that are mentally and socially stimulating is also beneficial, such as hanging out with friends, volunteering, or group recreational activities.
- Parenthood and other caregiving responsibilities also add layers of this protective reserve to your brain.
- Living alone isn't associated with poorer cognitive function, but the more you engage in social interaction outside the home, the better.
Leisure activities with cognitive demands. Engaging in hobbies that challenge your brain, such as playing games, reading, doing crafts, learning new skills, or learning a new language, can help build cognitive reserve.
- The key is to participate in activities that stimulate your brain instead of more passive pastimes, such as watching TV or scrolling social media.
Sleep. Meeting the recommended 7–9 hours of sleep is another strategy that can help you build cognitive reserve.
- Factors such as the time it takes you to fall asleep, the quality of your sleep, and the amount of time you spend in the “deep sleep” stage of sleep are also important.
- If you feel you’re not getting the rest and recovery you need, despite spending 7–9 hours in bed, you could benefit from seeing a medical provider.
Nutritious food. A diet high in polyunsaturated fatty acids, polyphenols, and antioxidants and low in added sugar and saturated fats supports cognitive health.
- Since you eat food and not nutrients, the Mediterranean Diet is an example of a dietary lifestyle that is rich in nutrients that support brain health and cognitive longevity.
- Choose colorful fruits and veggies, whole grains, nuts and seeds, olive oil, and fatty fish as frequently as possible to boost your cognitive reserve.
- Avoiding excessive calorie intake can help prevent cognitive decline.
Exercise. Regular physical activity of moderate to vigorous intensity, lasting 45–60 minutes at least once a week, can also boost your cognitive reserve.
- As you improve your cardiorespiratory fitness, you also improve the availability of oxygen and glucose to your brain, supporting brain function.
- Exercise releases brain chemicals known as "brain fertilizers" because they help the formation and maintenance of “neuronal connections.”
Substance use. Reducing alcohol intake, avoiding smoking, and managing medications wisely can protect your cognitive health.
- Substance use negatively affects your brain's ability to build and maintain neuronal connections and cognitive reserve.
Cognitive reserve is powerful protection against cognitive decline that often comes with injuries, neurodegeneration, and aging. Regardless of your age, history of injury, and previous mental health conditions, it's never too late to focus on building cognitive reserve. Start small and focus on building healthy habits to help you achieve this goal. Go back over the “How cognitive reserve can protect your brain” section of this article and choose 1–3 lifestyle changes you’d like to make. Then, build a plan to build habits to support your cognitive reserve-building journey. If you want to learn more about how to build lasting habits, check out the HPRC Strategic Habits worksheet.