Many years ago, I was taught that the number of neurons (brain cells) a person has is fixed and that the number diminishes as the person gets older. The diminishing number of neurons will eventually lead to memory loss and even dementia.
Later, research shows this to be false and that the brain does indeed grow new neurons.
One question came to my mind: “If the brain can grow new neurons, how do I get the brain to grow them?” I am, of course, assuming that more neurons mean more brainpower.
Neurogenesis is the process where new neurons are formed in the brain.
This process shows that humans can and do produce brain new brain cells (Eriksson et al.), and mostly in the hippocampus, a region of the brain that deals with learning, memory and motivation.
What is even more amazing than the discovery of neurogenesis is the follow-up discoveries: (1) what is the functional role of neurogenesis in the brain, and (2) what regulates the process of neurogenesis.
First, it turns out that neurogenesis is highly correlated with learning and memory (Deng et al.). It is also correlated with mood (Jacobs et al.)
Second, your daily behaviours can tell your brain to make fewer cells (“down-regulate”) or to make more brain cells (“up-regulate”). This means that what you do at work can directly influence the brain. But, is there evidence to support this position?
And, if there is, what can you do to increase neurogenesis?
How to increase neurogenesis
Here are some of the properties of neurogenesis that you should know.
Physical and mental exercise
Research shows that neurogenesis is boosted by exercise (Pereira et al.). In this human study, participants did a voluntary gross motor activity for almost an hour, four times a week for 12 weeks.
What does this suggest? Schools that reduce or eliminate physical education for their students are making a serious, brain-changing mistake. The same goes for workplaces where workers are discouraged or prevented from physically moving around. Both classroom teachers and workplace managers should promote movement and activity instead.
Another randomized controlled trial involving 120 older adults showed that aerobic exercise training increases the size of the anterior hippocampus, leading to improvements in spatial memory (Erickson et al.).
Research also shows that physical and mental training can increase the number of new cells that mature into functional neurons in the adult brain. Physical activity especially aerobic exercise greatly increases the number of new neurons that are produced in the hippocampal formation. This can increase cognitive performance (Curlik).
According to some research, meditation may increase the size of the hippocampus. These results suggest that taking part in MBSR (Mindfulness-Based Stress Reduction) is associated with changes in grey matter concentration in brain regions involved in learning and memory processes, emotion regulation, self-referential processing, and perspective-taking (Hölzel et al.).
Another study found that just by meditating about 13 minutes daily for 8 weeks, you can enhance your attention, working memory, and recognition memory and decrease your state anxiety (Basso et al.).
One study showed that dietary restriction can increase hippocampal neurogenesis (Kitamura et al.). Since this study was done over 12 weeks, you probably won’t turn you into a genius by skipping one or two meals.
But what does this mean? This suggests that by eating less, you can increase neurogenesis which in turn support your mood and memory. You can help promote “smarter eating” (i.e. eating less) to your colleagues at work, as well as eating more of the so-called “brain foods” that are good for the brain.
Other research showed that diets that are high in fat and refined sugars, as well as alcohol, can negatively affect neurogenesis (Poulose et al.). So eat less of these foods.
We know that sleep loss reduces neurogenesis. In fact, prolonged sleep loss can inhibit hippocampal neurogenesis independent of any effects from the stress hormones. We already know excess cortisol reduces neurogenesis.
Just as minor sleep restriction may interfere with the enhancement of neurogenesis associated with learning processes, prolonged sleep disruption may even endanger hippocampal integrity, thereby leading to cognitive dysfunction and contributing to the development of mood disorders (Meerlo et al.).
Sleep can make you smarter and a lot less irritable.
What does this suggest? Share this information with parents. Remind kids that their brain likes the “downtime” even if there’s one more tweet or email.
Let’s “flesh out” what you learned from the studies above: exercise, eat less, and get enough sleep. That sounds pretty ho-hum. But that’s just for starters! There are actually over 20 known factors that influence neurogenesis!
Until then, keep in tune with the research. Remember: everything you do in your workplace is likely to have some effect on your brain.
For ideas on improving your memory, read Improve Your Memory.
- Basso J., McHale A., et al. “Brief, Daily Meditation Enhances Attention, Memory, Mood, and Emotional Regulation in Non-Experienced Meditators.” Behavioural Brain Research, Vol 356, Jan 2019, pp 208-220.
- Curlik D. M. 2nd, Shors T. J. “Training Your Brain: Do Mental and Physical (MAP) Training Enhance Cognition Through the Process of Neurogenesis In the Hippocampus?” Neuropharmacology, vol 64, Jan 2013.
- Deng W, et al. “New Neurons and New Memories: How Does Adult Hippocampal Neurogenesis Affect Learning and Memory?” Nature Reviews Neuroscience, vol. 11, no. 5, 31 Mar. 2010, pp. 339–350.
- Erickson K., Voss M., et al. “Exercise Training Increases Size of Hippocampus and Improves Memory.” Proceedings of the National Academy of Sciences, Feb 2011.
- Eriksson P., Perfilieva E., et al. “Neurogenesis in the Human Hippocampus.” Nature Medicine, vol. 4, no. 11, 1998, pp. 1313–1317.
- Hölzel B. K., et al. “Mindfulness Practice Leads to Increases in Regional Brain Gray Matter Density.” Psychiatry Research, vol. 191, no. 1, 2011, pp. 36-43.
- Jacobs B., Praag H., Gage F. “Adult Brain Neurogenesis and Psychiatry: A Novel Theory of Depression.” Molecular Psychiatry, May 2000, pp 262–269.
- Kitamura T., Mishina M., Sugiyama H. “Dietary Restriction Increases Hippocampal Neurogenesis by Molecular Mechanisms Independent of NMDA Receptors.” Neuroscience Letters, Jan 30, 2006.
- Meerlo P., Mistlberger R. E., et al. “New Neurons in the Adult Brain: The Role of Sleep and Consequences of Sleep Loss.” Sleep Medicine Reviews, vol 13, Jun 2009, pp. 187-194.
- Pereira A. C., Huddleston D. E., et al. “An In Vivo Correlate of Exercise-Induced Neurogenesis in the Adult Dentate Gyrus. Proceedings of the National Academy of Sciences USA, Mar 27, 2007.