The brain is the body’s control center, regulating thoughts, movements, and cognition, among other physiological processes. And like other bodily systems, the brain is not immune to aging. Cognitive functions—memory, executive function, language, attention, and processing speed—can decline with age. But understanding your genetics and the effect of lifestyle and environmental factors on cognitive health can help you take actionable steps to delay cognitive aging so you can live a healthier longer life, doing activities you love.
Here we discuss cognitive aging and how genetics and lifestyle factors influence and can delay cognitive aging while improving your healthspan—the duration of life spent in good health.
Key takeaways:
- Cognitive aging is the age-related decline of cognitive abilities, such as memory, executive function, processing speed, and attention.
- Lifestyle and environmental factors—such as diet, sleep, alcohol intake, physical activity, air pollution, and chronic health conditions—contribute to cognitive aging.
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InsideTracker’s genetic risk score for cognitive decline includes up to 1,225 genetic markers that can affect a person’s risk of accelerated cognitive decline before age 70.
- You can delay cognitive aging despite an elevate genetic risk; lifestyle interventions include physical activity, dietary modifications, 7-8 hours of sleep, and brain games.
What is cognitive aging?
Cognitive aging refers to the age-related decline in cognitive abilities like memory, language, attention and processing speed, visuospatial ability, and executive function—the mental processes responsible for behaviors like scheduling, planning, and multitasking. [1]
Cognitive aging occurs throughout the lifespan and is not attributable to any disease, resulting instead from structural and functional changes in the brain that occur due to lifestyle, environmental, and genetic factors. While it is a natural process, it’s possible to strengthen and delay the decline of certain aspects of cognitive function. [1]
Maintaining optimal cognitive health ensures independence, mobility, and participation in social, physical, and daily activities. It is never too early to start prioritizing cognitive health—knowing the causes and signs of cognitive aging can prepare you to make lifestyle modifications to preserve cognitive health as you age.
What causes cognitive aging?
Age-related cognitive decline is likely the result of multiple factors. Lifestyle and environmental factors that contribute to cognitive aging include:
- High blood pressure and heart disease: Hypertension can put pressure on blood vessels that leads to changes in the brain, and can result in stroke or cognitive impairment.
- High blood sugar levels and type 2 diabetes: Persistently elevated blood sugar levels damage blood vessels in the brain, leading to brain cell death and increasing the risk of cognitive decline.
- Inflammation: Higher levels of systemic inflammation linked with aging promote the release of more pro-inflammatory molecules that can damage brain cells and blood vessels.
- Physical inactivity and sedentary lifestyle: Lack of physical activity can contribute to other health issues such as weight gain and elevated blood sugar, and difficulty with sleep, which can affect cognitive health and function. Conversely, regular physical activity contributes to lower blood sugar levels, decreased inflammation, and changes to chemicals in the brain that influence brain cell health and the development of blood vessels.
- Poor diet: Certain foods like those high in fat or sodium can contribute to health problems that impact the brain. In particular, more processed and refined foods can affect blood sugar and insulin sensitivity, which may lead to inflammation and oxidative stress in the brain that damage brain cells.
- Sleep issues: Sleep is a period of mental and physical restoration that solidifies memories and the mind-muscle connection. Poor or inadequate sleep can affect cognition by impacting memory formation, concentration, and other aspects of brain health.
- Smoking: Chemicals in cigarette smoke damage and inflame blood vessels, causing them to narrow. This can limit blood flow to the brain and increases the risk of cognitive aging and stroke.
- Excessive alcohol intake: Too much alcohol can slow or impair communication between neurons (brain cells). And long-term excessive alcohol intake can affect cognitive health, specifically balance, memory, coordination, and emotions.
- Social isolation: Loneliness can contribute to impaired cognitive function through decreasing brain cell connections and the mental stimulation that occurs with social interactions.
- History of brain injuries: Damage to the brain from falls or injury can change brain function and structure, leading to issues with processes related to cognitive health, such as memory, processing, thinking, reasoning, and speech.
- Exposure to air pollution: Greater exposure to air pollution may be associated with cognitive decline. Ultrafine pollutant particles can enter sensory organs (nose and mouth) to reach the brain, where they cause inflammation resulting in adverse changes to brain structure and function. [2-4]
How do genetics contribute to cognitive aging?
Though lifestyle factors such as a healthy diet and physical activity benefit cognitive function during aging, research shows that genetics also affect the rate of cognitive decline. Studies suggest that multiple genes may contribute to the decline of various cognitive domains at different periods in the aging process. While all of the genetic variants influencing rates of age-related cognitive impairment are not yet known, genomic scientists can create polygenic scores by modeling aggregate measures of cognitive aging in individuals of different ages to predict an individual’s risk of cognitive decline. [5-7]
Research continues to evolve on how genetics contribute to cognitive aging. But studies suggest that a polygenic score related to educational attainment can predict cognitive decline through the age of 70. In contrast, a single apolipoprotein E gene variant (APOE4) has the greatest effect on cognition past the age of 70. [5] APOE4 is a well-established genetic risk factor for cognitive impairment and dementia that influences the association between lifestyle and environment and cognitive functioning. While this variant is an important genetic factor, it is not the sole determinant of cognitive aging risk, and a wide range of variants must be considered for a more comprehensive understanding.
InsideTracker’s genetic risk score for cognitive decline includes up to 1,225 genetic markers that can affect a person’s risk of accelerated cognitive decline before age 70 (i.e. most of their lifespan). Knowing your genetic risk score and making appropriate lifestyle changes can help overcome a predisposition to accelerated age-related cognitive degeneration—just because your genetics show an increased risk of cognitive aging does not mean you can’t delay cognitive decline.
Early signs of cognitive decline
Early signs of cognitive aging affect thinking speed and attention and may include the occasional memory loss and forgetfulness. Other symptoms may include: [8]
- Struggling to pay attention
- Difficulty with multitasking
- Being slower with finding words or remembering names
- Losing things occasionally
Signs of age-related cognitive decline differ from person to person, so knowing what cognitive health looks like for you can help you recognize early signs and take steps to preserve cognition. And understanding how your genetics can contribute to cognitive aging enables you to take action before those early signs appear.
How can I delay cognitive aging to improve healthspan?
It’s never too late to adopt lifestyle modifications to delay cognitive aging. While starting young may be preferable, implementing positive lifestyle habits at any age can help slow cognitive aging. To know which interventions are best suited to you, it’s important to understand your baseline blood biomarker levels, which can be combined with your DNA and fitness tracker data for a more holistic view of your health.
Nutrition
The MIND diet—an eating pattern designed to protect the brain—can delay cognitive aging. The MIND diet emphasizes vegetables (especially leafy green vegetables), nuts, berries, beans, whole grains, seafood, poultry, olive oil, and wine while discouraging red meats, butter, cheese, pastries and sweets, and fried or fast food. One study found that participants in the highest tertile of adherence to the MIND diet could slow cognitive aging by 7.5 years compared to those in the lowest tertile of dietary adherence. [9] Research also indicates that while cooking fish once weekly may contribute to slower cognitive aging, limiting cholesterol intake and consuming more a-linolenic acid (ALA)—a form of omega-3 fatty acids—may be more beneficial for preserving cognitive function with aging. [9,10]
The MIND diet is also rich in flavonoids (bioactive compounds found in plants with antioxidant and anti-inflammatory properties), which may contribute to delayed cognitive aging. In particular, a higher intake of flavanols, a specific subclass of flavonoids abundant in berries, is associated with delayed cognitive aging—particularly in areas of cognition related to episodic, semantic, and working memory and perceptual speed—independent of lifestyle factors. Though not completely understood, flavanols may support cognitive health through their anti-inflammatory and antioxidant capacities, which help reduce neuroinflammation and prevent or ameliorate oxidative stress. [11,12]
Exercise
Research suggests that exercise can enact positive changes in areas of the brain greatly affected by aging and reduce cognitive declines, regardless of baseline cognitive function. In particular, physical activity benefits executive control processes, which are often highly susceptible to age-related declines. [13] Research suggests at least 150 minutes of moderate-to-vigorous intensity exercise weekly. [14] And engaging in both aerobic and resistance training may benefit cognitive function in adults older than 50. [15]
Sleep
There may be an optimal amount of sleep to maintain cognitive function. One study of more than 28,000 people found that participants who slept 3 to 4 hours or more than 10 hours exhibited an increased risk of memory impairment compared to those who regularly slept 7 to 8 hours nightly. Frequently feeling tired in the morning was also associated with an increased risk of memory impairment. [16] Even one night of poor sleep can affect brain health and function, potentially causing mood disturbances and confusion. [17]
Poor sleep is also associated with an increased risk of metabolic disorders, such as hypertension and elevated blood sugar—contributors to cognitive aging. [18]
Challenging the mind
Brain games can improve cognitive function and prevent age-related declines, specifically in cognitive domains related to processing speed, attention, and short-term memory. Studies have indicated that participating in brain games for at least 6 months can benefit specific parts of cognitive function, including executive function. [19-21]
The importance of prolonging cognitive health
Cognitive aging affects the ability to live independently, engage in activities, maintain autonomy, and preserve your sense of self and identity. Tasks that may have previously felt easy—such as making decisions, driving a car, cooking meals, and other activities of daily living—become difficult. Maintaining optimal cognitive function is necessary to preserve cognitive health and delay aging. And many interventions exist to prevent, attenuate, or adapt to cognitive changes. Implementing these behaviors early on can support brain health throughout your life.
References:
- https://www.ncbi.nlm.nih.gov/books/NBK316207/#:~:text=What%20Is%20Cognitive%20Aging,a%20quantifiable%20level%20of%20function.
- https://pubmed.ncbi.nlm.nih.gov/15536110/
- https://www.nia.nih.gov/health/cognitive-health-and-older-adults#reduce%20risks
- https://pubmed.ncbi.nlm.nih.gov/30935305/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7515838/
- https://www.sciencedirect.com/science/article/abs/pii/S0197458019300740?casa_token=J0F1F63BMGcAAAAA:GEOMJOOLuLmiBRKXkyjuM0EU7dMHd8UdcU1a6ZsRWxBAMYwFsFv65QWICSPmCEnu5_SkWz7S#appsec1
- https://alz-journals.onlinelibrary.wiley.com/doi/abs/10.1002/alz.037972
- https://www.nia.nih.gov/health/how-aging-brain-affects-thinking
- https://pubmed.ncbi.nlm.nih.gov/26086182/
- https://pubmed.ncbi.nlm.nih.gov/28488130/
- https://pubmed.ncbi.nlm.nih.gov/36414424/
- https://pubmed.ncbi.nlm.nih.gov/32320019/
- https://pubmed.ncbi.nlm.nih.gov/18094706/
- https://pubmed.ncbi.nlm.nih.gov/27153869/
- https://pubmed.ncbi.nlm.nih.gov/28438770/
- https://pubmed.ncbi.nlm.nih.gov/21532950/
- https://pubmed.ncbi.nlm.nih.gov/18076267/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3703752/
- https://pubmed.ncbi.nlm.nih.gov/33503851/
- https://pubmed.ncbi.nlm.nih.gov/32980574/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7504145/
