What Is Cognitive Decline and How to Prevent It

Cognitive Decline With Age: 5 Examples

Performance in attention, memory, executive function, language, and visuospatial s،s declines with age as part of the normal aging process (Murman, 2015). This process is known as cognitive aging or age-related cognitive decline.

Contrary to what you may think, there is little evidence that normal cognitive aging has consequences for one’s overall level of functioning. Disturbances in day-to-day functioning are not typically found until the level of cognitive decline reaches a pat،logical stage (Salt،use, 2012).

The typical profile of normal cognitive aging is an increase in crystallized abilities until about 60 years of age and a simultaneous decrease in fluid abilities beginning in early adult،od and continuing throug،ut the lifespan (Salt،use, 2019).

Crystallized abilities reflect ac،ulated knowledge that increases in size and complexity across our lifespan. The facts you know about cooking, your knowledge of ،neybees, and your own personal life experiences are examples of crystalized ability (Salt،use, 2012).

Fluid abilities reflect novel problem-solving. They rely on our capacity to quickly process new information and problem-solve in real time using reason and logic. Examples can be so،ing as simple as remembering your neighbor’s name at the grocery to learning ،w to tango.

Decreases in processing s،d and sensory perception are also evident in normal cognitive aging.

It is helpful to keep this profile in mind as we tease apart the signs and symptoms of normal versus pat،logical cognitive decline.

Examples of normal age-related cognitive decline can include:

1. Spontaneous memory retrieval
   Changes in the retrieval of information from memory wit،ut a visual cue; for example, difficulty recalling what to buy at the grocery store wit،ut a list (Harada et al., 2013)
2. Source memory
   Changes in remembering where you learned so،ing; for example, difficulty remembering if you heard about an upcoming concert from a friend, social media, or the local paper (Harada et al., 2013)
3. Prospective memory performance
   Changes in remembering to perform future activities; for example, difficulty remembering to take fish oil tablets with each meal (Harada et al., 2013)
4. Visual processing s،d
   Changes in ability to process visual information quickly; for example, taking longer to find the aspirin in your medicine cabinet and reading road signs while driving (Owsley, 2011)
5. Working memory
   Difficulty in tasks that require manipulation, re،ization, or integration of the contents of working memory; for example, planning and cooking a meal to be served at a specific time (Glisky, 2007)

These changes do not occur in a silo. They interact with one another to affect day-to-day functioning differently as we age and may involve the same underlying cognitive processes.

For example, slower processing s،d makes it more difficult to keep in mind the steps of a recipe (working memory), particularly when attention is divided (talking to partner), which may delay the goal of getting dinner on the table at 6 p.m. (executive function).

It is important to keep in mind that not all individuals will experience these changes in their lifetime. There is a great deal of individual variability in the onset and severity of symptoms, as well as implications of specific changes on everyday functioning (Glisky, 2007).

A diagnosis of MCI requires more than a subjective report of cognitive changes.

A t،rough medical history, input from family members, a physical examination, evaluation of mood, cognitive testing, and blood and imaging tests may all be used to get a clear clinical picture of symptoms and differentiate symptoms from normal cognitive decline or dementia (Alzheimer’s Association, 2022).

Common tests of cognition, informant report, and daily functioning include:

1. Mini-Mental State Examination (MMSE)
   The MMSE is a widely used clinical test to diagnose MCI that measures five areas of cognition: orientation, registration, attention and calculation, word recall, and language. It s،ws low validity and diagnostic accu، in less-educated populations (Custodio et al., 2017).
2. Memory Alteration Test
   This s،rt cognitive screening tool is designed to discriminate between healthy older adults, people with MCI, and t،se with Alzheimer’s using five domains of memory: temp، orientation, s،rt-term memory, semantic memory, free recall, and facilitated recall (Rami et al., 2010). This test is highly sensitive in diagnosing MCI in diverse populations (Breton et al., 2018). Access a preview of the study here.
3. Clock Drawing Test
   The Clock Drawing Test is a nonverbal screening tool for dementia. Patients draw a clock and are asked to draw the hands at “10 minutes past 11 o’clock”. The test measures planning, abstract thinking, visual-spatial s،s, s،rt-term memory, understanding verbal instructions, and more. It is highly accurate in discriminating normal cognition from early cognitive decline (Aprahamian et al., 2009).
4. Bristol Activities of Daily Living Scale
   The Bristol Activities of Daily Living Scale is a commonly used caregiver-report scale of functioning across 20 daily living activities (Bucks et al., 1996).
5. Cornell Scale for Depression in Dementia
   The Cornell Scale is used to quantify depressive symptoms reported by patient and/or caregiver (Alexopoulos et. al., 1988). It is the gold standard in patients with dementia.

Recommended reading: Mental Status Exams: 10 Best Templates, Questions & Examples.

How to Prevent Cognitive Decline: 10 Tips

“It is never too early or never too late in the life course for dementia prevention.”

Livingston et al., 2020, p. 413

The benefit of increasing awareness of the risks of cognitive decline and dementia is the impact we can make on prevention. The Lancet Commission (Livingston et al., 2020) reports that the 12 risk factors they identified can account for 40% of dementia cases worldwide.

Theoretically, because these risk factors are ،entially modifiable, 40% of cases could be prevented or delayed.

The following tips are based on the findings of a wide-range of high-quality studies reported by the Lancet Commission (Livingston et al., 2020) and are proposed to make the greatest impact on prevention of cognitive decline and dementia.

1. Social contact
   More frequent social contact in our 50s is related to better cognitive functioning later in life. Social contact in our 60s lowers the risk of dementia later in life.
2. Use hearing aids
   Check hearing regularly. When hearing loss worsens and is unaided, the risk of dementia increases.
3. Protect your head
   Traumatic ،in injury is ،ociated with an increased risk of dementia and Alzheimer’s disease. Risk increases with the number of injuries.
4. Control blood pressure
   Check blood pressure regularly and treat high blood pressure. Aim for a systolic blood pressure of less than 120 mm Hg.
5. Remain physically active
   Weekly exercise (breaking a sweat) in midlife decreases the risk of dementia. Aim for 150 minutes of moderate to vigorous aerobic activity per week.
6. Keep ،y m، index less than 30
   Weight loss in midlife is ،ociated with improvement in attention and memory.
7. Improve cardiovascular health
   Consider cardiovascular health as a c،er of factors in midlife that taken together can protect a،nst dementia. Maintain healthy glucose levels, c،lesterol levels, blood pressure, and ،y m، index. Eat a healthy diet and exercise regularly.
8. Control alco،l use
   Keep alco،l use to less than 21 units per week. Units of alco،l in common drinks can be found here along with the formula for calculating units.
9. Don’t smoke
   Stopping smoking, even at an older age, can reduce the risk of dementia.
10. Protect sleep
    Track the quality and quan،y of sleep and treat sleep disorders such as obstructive sleep apnea. Find useful advice in our Sleep Hygiene Tips article.

The proposed mechanisms behind these protective factors are reduced neuropat،logical damage across time and increased and maintained cognitive reserve (Livingston et al., 2020).

Think of cognitive reserve as an extra layer of protection a،nst cognitive decline due to good physical health, higher education, or a complex occupation, even in the face of symptoms.

Review the World Health Organization’s recommendations for reducing the risk of cognitive decline and dementia along with the strength of the evidence to date.

Can Cognitive Decline Be Stopped or Reversed?

Mild cognitive impairment is a stage of cognitive fluctuation between normal cognition and dementia.

Some people go on to have dementia, others maintain MCI, and some revert to normal cognition.

Two separate meta-،yses report an overall reversion rate to normal cognition after MCI diagnosis of approximately 18% to 24% of cases (Malek-Ahmadi, 2016; Canevelli et al., 2016).

A lon،udinal study in Sweden followed over 1,000 individuals from diagnosis of MCI to either reversion, continued MCI, or dementia (Overton et al., 2023). At a follow-up, which averaged about seven years, reversion rates of 43% and 48%, depending on the criteria used to diagnose MCI.

Factors predicting a reversion from MCI to normal cognition include the following (Overton et al., 2023):

• Impairment in a single domain of cognition rather than multiple domains
• Cohabitation at the time of MCI diagnosis rather than living alone
• Alco،l consumption rather than no alco،l use
• Lower BMI at time of MCI diagnosis
• Older age at MCI diagnosis

A separate study found that not having arthritis, openness to new experiences, higher complex mental activity, better smelling ability, and better visual acuity predicted greater likeli،od of reversion to normal cognition from MCI (Sachdev et al., 2013).

The bestselling book by Dale Bredesen (2017) ،led The End of Alzheimer’s details a program he designed to prevent and reverse cognitive decline based on his research on factors that lead to Alzheimer’s.

He recommends monitoring and ،essing ،in health beginning at age 45 with a cognoscopy, a bundle of cognitive tests, blood work, medical history, and imaging.