The previous two articles discussed 1) the impact on cognition after a concussion and 2) cognitive rehabilitation after a concussion, yet there are a few factors to consider when we discuss cognitive health, or brain health.
When it comes to our health and wellbeing, there are many factors that reciprocally interact. We also need to look at cognition holistically. Think back on a time when you were sleep deprived, or sick with a cold, or emotionally overwhelmed. You likely were not thinking as sharply as you usually do. After a concussion there are direct and negative impacts to cognition, due to the diffuse nature of the injury, as discussed in that first article. Yet, there are also secondary impacts to cognition. The purpose of this article is to go beyond concussion and explore the factors that impact cognition more broadly. Let us title this holistic view of cognition – brain health.
We all know the importance of a good night’s sleep the night before an exam, that sleep is the best medicine, and perhaps that sleep may play a role in memory consolidation. Sleep is one of those lifestyle variables that very obviously impacts cognition. Sleep deprivation has been shown to reduce the capacity for attention (focused, sustained, and divided), working memory, long-term memory, processing speed, reaction time, response inhibition, and executive functioning (including logical reasoning, decision making; Alhola & Polo-Kantola, 2007).
In addition, chronic partial sleep deprivation may also lead to reduction in cognitive performance and may contribute to the formation of Alzheimer’s like pathology in the brain (Alhola & Polo-Kantola, 2007; Holth et al., 2019). Therefore, to ensure that your brain is healthy, make sure that you’re getting enough sleep!
If a panacea does exist, it’s surely exercise. We all know how important exercise is to physical and mental health, but exercise also has many benefits on cognition. In meta-analyses looking at the impact of regular aerobic exercise on cognition in adults (Smith et al., 2010) we see improvement in attention, processing speed, memory (although not working memory), and executive functioning. The effect is also present across the lifespan, seen in children (Sibley & Etnier, 2003) and in older adults (Northey, Cherbuin, Pumpa, Smee, & Rattray, 2018).
In a meta-analysis of the effects of acute exercise on cognition, testing during, or immediately after, exercise we see a small positive effect on cognition in general (Chang, Labban, Gapin, & Etnier,., 2012). There are even greater improvements in cognition for individuals with higher fitness levels, after longer periods of exercise, and also most impact on executive functioning. Therefore, a method to improve cognition – is regular exercise.
While meditation is an ancient practice, it has only recently been the target of empirical study. We see meditation programs implemented in some academic settings, and while there are not many studies that evaluate the outcome of academic success, we do see some positive effects, especially with transcendental meditation (Waters, Barsky, Ridd, & Allen, 2015). There is evidence that suggests that mindfulness training may improve focused and sustained attention, and perhaps working memory and executive functioning, although there are not many studies and those that are done have limitations in design and population (Chiesa, Calati, & Serretti, 2011). Thus, while we need more research in the area, there is some good preliminary evidence supporting meditation techniques having a positive effect on cognitive functioning.
This may be more of a vague concept, but we know that individuals with clinically diagnosed depression do have cognitive impairment, and that when mood improves, cognition does as well (Lam, Kennedy, Mclntyre, & Khullar, 2014).
We know that happiness also aids in cognitive functioning. Whether mood is manipulated in a lab setting, or happiness stems from something external, people perform better on tasks of attention, switching attention, problem solving and cognitive flexibility, and this may be modulated by happiness changing specific neural activation states (Subramaniam & Vinogradov, 2013).
Going beyond studies looking at neurocognition as an outcome, we also see happiness promoting better functioning and success in school and in the workplace. In general, be happy, it will make your brain healthier in a variety of ways, and thus improve cognition.
There is an entire division of cognition referred to as social cognition, and to keep these skills sharp it follows that we would have to practice them. A majority of the research has been done in populations of older adults, but larger social networks and closer friendships likely have a protective factor when it comes to cognition. A meta-analysis found relationships between social activity and global cognition, executive functioning, working memory, visuospatial, and processing speed (Kelly et al., 2017). It is possible that happiness is the meditating variable in this relationship, and we do need research in other age groups, but a healthy social life, may make you smarter.
We know that diet is a crucial component when we examine physical health, but does diet also play a role in cognitive health and wellbeing? If we stick with the older adult group the traditionally promoted omega-3s and vitamin B showed no effect on cognition, yet there were some studies supporting the possible prevention of cognitive decline with green tea extract, Concord grape juice, chromium picolinate, beta-carotene, and multi-vitamins (Forbes, Holroyd-Leduc, Poulin, & Hogan, 2015). Additionally, a poorer diet may be linked to the development of poorer health and cognitive dysfunction (Gomez-Pinilla & Tyagi, 2013).
In older adults a Mediterranean-style diet (larger quantities of fruits, vegetables, and fish, and lower consumption of dairy, red meat, and sugars than a typical Western diet) slowed cognitive decline and improved memory and executive functioning (Hardman, Kennedy, Macpherson, Scholey, & Pipingas, 2016). Again, we lack in the breadth of research, yet the theory is sound. You need to be getting enough of each nutrient and eating a balanced and healthy diet in general to best promote brain health.
This is yet another topic that will be focused on older adults in regards to research, but to promote cognitive health, you need to challenge your brain. We know that keeping your brain active can prevent cognitive decline, as we can see greater hippocampal volume (a region very involved in memory) in older adults that had partaken in more complex cognitive activity over their lives (Valenzuela, Sachdev, Wen, Chen, & Brodaty, 2008), and with cognitive exercise likely preventing, or postponing, the onset of dementia (Valenzuela & Sachdev, 2009).
We also know that cognition has a positive relationship with education, occupation including profession, and cognitively stimulating activity in healthy older adults (Opdebeeck, Martyr, & Clare, 2016). Even though this research is exclusive to older adults, it again makes theoretical sense that using our brains, learning new skills, engaging in cognitively challenging activity, will promote cognitive health across the age span. So stay active, and when in doubt, pick up a new skill!
In summary, to promote cognitive functioning, you need to promote brain health in general. The beauty of it, is that all of this is all common sense. If you’re living a healthy lifestyle, your cognitive functioning, along with your psychological and physical functioning, will also be at it’s peak.
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