Cognitive Reserve: How to Build It Up
Cognitive decline is among the normal processes of aging, which simply means that the brain doesn't work as well as it used to. Cognitive decline, which can lead to dementia or other brain diseases, is caused by factors of the environment that are not conducive to normal brain health.
On the other hand, there are people who don’t show apparent symptoms of dementia when alive but at autopsy, they show brain changes consistent with advanced Alzheimer’s disease. Such people have cognitive ability to offset the damage and continue to function as usual. This is called cognitive reserve. People with greater cognitive reserve are better able to stave off the degenerative brain changes associated with dementia or other brain diseases, such as Parkinson's disease, multiple sclerosis, or a stroke.
The greater cognitive reserve means greater resilience to neuropathological damage. People with greater cognitive reserve have an ability to optimize or maximize performance through differential recruitment of brain networks through alternative cognitive strategies, which are the specific methods that people use to solve problems, including all sorts of reasoning, planning, arithmetic, etc.
Successful early brain development during childhood is critical. It provides a person with a greater number of neurons, more synapses (neural connections), and multiple pathways to perform any task. It has been found that socio-emotional abilities such as self-discipline, perseverance, adaptability and working well with others are firmly rooted in successful childhood development. That is why children, who are able to resist impulses, regulate emotions and pursue long-term goals, can perform complex tasks better. This ability helps them build cognitive reserve as they grow up.
The brain has the ability to bypass damage and create new pathways on its own. Hence, there are ways that can help to improve cognitive reserve and cognitive function.
Ways to build up cognitive reserve
Do regular exercise – Regular exercise is good for the brain because a hormone called irisin is produced in the brain during endurance exercise. The so-called exercise hormone has neuroprotective effects. Higher levels of irisin in the blood can activate genes involved in learning and memory. The findings, published online October 10, 2013, in the Cell Press journal Cell Metabolism, indicate that this exercise-induced hormone helps guard against neurodegenerative diseases and improve cognition in the aging population. The exact mechanisms underlying these effects are unclear. One important player is thought to be a growth factor named brain-derived neurotrophic factor (BDNF). Raising levels of irisin in the circulation causes it to cross the blood-brain barrier, where it increases expression of BDNF and activates genes involved in cognition.
Moreover, the hippocampus shrinks in late adulthood, leading to impaired memory and increased risk for dementia. Hippocampal and medial temporal lobe volumes are larger in fitter adults and physical activity increases hippocampal perfusion, but the extent to which aerobic exercise training can modify hippocampal volume in late adulthood remains unknown.
Do things differently – Doing things repeatedly, in the same way, makes the brain react the same every time. Doing things differently makes the brain to react differently by recruiting different sets of neurons. This is how we can form alternative neural pathways to perform the same activity. This unique quality of our brain is called neuro-plasticity. So take a different route home.
Don’t stop learning – It has been found that sustained engagement in learning new skills, which activated working memory, episodic memory, and reasoning over a period of 3 months, would enhance cognitive function in older adults. Surprisingly, there are limited cognitive benefits of sustained engagement in social activities because many of such activities fail to challenge our brain. Moreover, such social activities become boring and mundane after some time unable to provide enough mental stimulation. So learn something new every day. Read a new book. There are endless possibilities!
Do something challenging – By trying to do something creative like writing or painting, we stretch our brain’s abilities even though we are not good at it. With regular practice, we can get better at such an activity and even excel at it with intelligent perseverance. There goes an old saying - “you cannot teach old dogs new tricks”. But many studies show that cognition can be trained at all ages. In particular, middle age individuals, as well as older individuals, can learn techniques to boost their memory. The recipe for an effective mental exercise should include variety, challenge, and novelty. Learning and changing are never easy because it requires us to get out of our comfort zone. Often, the fear of failing is another key obstacle to learning.
Have regular sleep – During sleep, our brain clears out harmful toxins, a process that may reduce the risk of Alzheimer's. It has been found that Alzheimer's and all other diseases associated with dementia are also linked to sleep disorders, which increase the build-up of beta-amyloid protein in the brain. So, adopting strategies of good sleep hygiene is another approach to Alzheimer's prevention
Reduce weight and manage type-2 diabetes – A new study by Yale University published Oct. 19, 2017, in JCI Insight, shows that both obesity and type-2 diabetes are linked to decreased metabolism in the brain. This hypometabolism is also associated with Alzheimer's disease, but researchers have not pinpointed why. So, it is prudent for people to keep their weight within normal limits and manage type-2 diabetes well so that they can stave off the onset of dementia or Alzheimer’s disease.
Though cognitive decline is inevitable, it can be countered effectively by building up high levels of cognitive reserve. We can build cognitive reserve through active learning, regularly engaging in mentally stimulating activities, doing regular exercise, having adequate sleep every day, by reducing weight if overweight or obese, and managing type-2 diabetes properly if diabetic. The brain shrinks with disuse and grows with use. It can be made to stay plastic through different strategies of brain health.
- Stern Y. Cognitive reserve in ageing and Alzheimer's disease. Lancet Neurol. 2012 Nov; 11(11):1006-12. Pubmed.
- Exercise training increases size of hippocampus and improves memory Crossref DOI link: https://doi.org/10.1073/PNAS.1015950108
- Published: 2011-02-15 Update policy: https://doi.org/10.1073/PNAS.CM10313 The Impact of Sustained Engagement on Cognitive Function in Older Adults, The Synapse Project Volume: 25 issue: 1, page(s): 103-112 Article first published online: November 8, 2013; Issue published: January 1, 2014
- Yale University "Lower brain glucose levels found in people with obesity, type 2 diabetes." ScienceDaily, 19 October 2017. <www.sciencedaily.com/releases/2017/10/171019100957.htm>.