Neurogenesis is the growing study of how mammals (including us) generate new neurons, brain cells, and new neuron pathways . . .
and it is revolutionizing science as we speak . . .
Movies and shows such as Limitless, Lucy, and The Big Bang Theory underscore our intense fascination with genius. Shows like these tap into a fantasy we all have – that of developing a mind that literally gleams with intelligence.
. . . to be steely smart. Wicked smart.
Who wouldn’t like to spend a day inside the mind and imagination of a genius like Michelangelo, Shakespeare, or Steve Jobs?
. . . And what could we accomplish if we could harness our full intelligence potential?
Today, most of us are wondering, is it even possible to become smarter as we grow older or are we constantly moving toward a state of mental degradation and neurodegeneration?
I talk to people all the time in the corporate world who are really worried about this—they feel like they can’t mentally go toe to toe with the generations beneath them who are younger, faster, and can pull more all-nighters.
But what if I were to tell you that new science is emerging in the field of neurogenesis, the science and study of how to intensify our brain’s number of neurons and the strength of these neurons that is proving that we can become smarter every single day, no matter how old we are.
We grow new neurons and brain cells each day, you know. We have just been losing all of them because we didn’t know how to keep them, strengthen them, and encourage them to proliferate.
My research this week has me all excited about neurogenesis and I’ve learned a lot I want to share with you—so let’s go.
P.S. Some of you brainiacs may have already heard about neurogenesis – but I bet you haven’t done the massive research binge on it I have, so you’ll learn something too.
Make 2017 The Year You Expand Your Mind
The question boils down to Can we get wicked smart if we spend as much time on our minds as we do our body?
What I have learned these past two weeks is yes.
Today, I’m going to tell you everything I know so far (scientists are still learning too, so . . .) about how to get your brain firing on more cylinders than you ever thought possible.
What We Had Thought and What We’re Thinking Now
The authors of ThInk: Art, Science, and the Brain sum up the history and new advances in neurogenesis below:
One specific aspect of neuroplasticity that has received much attention over the past two decades is adult neurogenesis – the notion that new neurons can be produced in an adult brain. Until the mid-1960s it was firmly believed that neurogenesis in mammals ends in the period just after birth. Technological developments in the 1990s led to an ongoing period of intensive research in this area, and it is now well-established that every day thousands of new neurons are produced in the adult mammalian brain (Cameron and McKay, 2001; Spalding et al., 2013). Many of these new neurons are produced within a region of the brain called the hippocampus, which has long been established as being critical for learning and memory processes.
Although the process of neurogenesis has been well-studied, it is only very recently that the specific functional or behavioural consequences of neurogenesis have been considered.
What we’re learning about now are these “behavioral consequences” – how we can use lifestyle and diet to become smarter and smarter . . . . to grow new neurons, strengthen these new neurons so we can keep them, then growing some more neurons and so on and so forth.
We’re still fuzzy on two things and two things only—and you’ll see these numbered 3 and 4 on my list of ways to enhance neurogenesis—Mental training and environmental enrichment—and that’s because they haven’t yet moved to human studies of these aspects.
But they will.
So let me get started sharing the fruit of my massive research exploration into neurogenesis. I’m also going to include a great reading list below so that you can read more about neurogenesis yourself!
Brain Plasticity and Its Importance
A major finding that has changed our thinking in the field of neuroscience is the discovery that we can enhance our brain’s plasticity. Now let me explain—plasticity is a good thing in our brain. It’s not some kind of negative “hardening process’ as some people think it is. As one researcher explains,
Brain plasticity (from the Greek word ‘plastos’ meaning molded) refers to the extraordinary ability of the brain to modify its own structure and function following changes within the body or in the external environment. The large outer layer of the brain, known as the cortex is especially able to make such modifications.
Brain plasticity underlies normal brain function such as our ability to learn and modify our behaviour. This means that there are ways that we can grow new neurons in our brains, strengthen the synapses between them and create new pathways between neurons, connecting ones that had no previous connections, lighting up our minds like the picture above.
A recent, 2011 article by “Adult Neurogenesis in the Mammalian Brain: Significant Answers and Significant Questions,” scientists present this area of study as an area of research literally ready to explode with new findings on how we can all become more “limitless” (underlining mine).
Adult neurogenesis, a process of generating functional neurons from adult neural precursors, occurs throughout life in restricted brain regions in mammals. The past decade has witnessed tremendous progress in addressing questions related to almost every aspect of adult neurogenesis in the mammalian brain. Here we review major advances in our understanding of adult mammalian neurogenesis in the dentate gyrus of the hippocampus and from the subventricular zone of the lateral ventricle, the rostral migratory stream to the olfactory bulb . . .We also discuss remaining questions related to adult neural stem cells and their niches, underlying regulatory mechanisms and potential functions of newborn neurons in the adult brain. Building upon the recent progress and aided by new technologies, the adult neurogenesis field is poised to leap forward in the next decade.
This picture below is one of the better photos of actual brain neurons I could find.
Those branches there growing from cell to cell, from neuron to neuron above – we create new ones of these every day, and we can strengthen these naturally—through physical and mental exercise and nutritional strategies.
In fact, scientists have been working on this fascinating process in experiment after experiment for some time now. Plug “neurogenesis” into Pub Med and you’ll see hundreds of recent studies into the phenomena.
See, at one point, scientists thought that we were limited to the number of neurons we were given at birth and that memories, learning, and experiences helped to strengthen those pathways, making us “smarter.”
But we were wrong. We grow all kinds of new neurons every day—they are just too weak to survive if we don’t strengthen them quickly—daily, as we grow them.
Now, what is important to do is one thing that I will make clear by the end of this article—you can only access maximal intelligence using both a mental and physical approach—as we are learning today. It takes exercise of both the body and the mind—and some other tricks I will share with you in a moment. So read on.
Get Smart 101
If you’ve ever wondered why you felt so much quicker when you were younger and in school, ask yourself “Well, what was I doing on a daily basis then that I’m not doing now?”
If you were younger, you might have been eating better and exercising more, which keeps your mind young.
Plus, you were probably exercising your mind more than we have to today, doing math problems, taking language classes, engaging in more extended thought by writing and reasoning your way through problems.
We lose that when we graduate, that constant brain exercise, and enter a world where our minds are not tested that much on a daily basis. Heck, technology has progressed to the point that the little brain exercise we get is in figuring out how to better manage our technology.
In other words, back in school, we were exercising brain and body – which is exactly what it takes to get smarter. That and some specific eating tricks.
In fact, there are many things you can do on a daily basis to ensure the health of your mind and to strengthen synapses and generate new brain cells.
Your mind is like any other muscle. Feed it right, exercise it right, and you’ll become as limitless in brain power as you can possibly be.
Here are the ways I’ve found through research, to grow new neurons, enhance the brain’s plasticity, and become more intelligent every single day.
Method One: Strategic Eating for Neurogenesis
There are three eating habits I have learned that help to grow new neurons and make us smarter: getting more DHA, intermittent fasting, and caloric restriction regimens.
Both calorie restriction and intermittent fasting are proving to have amazing powers for prolonging life, getting thin, preventing disease, improving brain function, and banishing the risk of neurodegenerative disease.
One theory as to why calorie restriction and intermittent fasting work is that they mimic ancestral eating patterns of feast and famine. Our ancestors had days when they were able to slay their prey and days of famine, where both produce and animal protein were scarce, such as in winter.
In terms of improving brain health, both caloric restriction and intermittent fasting have proven all kinds of benefits for brain health, especially, in terms of neurogenesis. .
During sudden, short-term fasting, not only do we see more activity in healing and restoring the brain, but we see an increase of ghrelin. Researchers now believe that ghrelin may in fact trigger the who neuro-generative process.
Ghrelin & Cognition
Multiple studies have shown a relationship between high levels of ghrelin and:
This is why intermittent fasting works so well to enhance cognition, Mark Mattson explains, adding that part of this effect is due to what cutting calories does to appetite hormones such as ghrelin and leptin,’ he explains. ‘When you are not overweight, these hormones encourage growth of new brain cells, especially in the hippocampus. This is the area of the brain which is involved in laying down memories. If you start putting on weight, , levels of ghrelin drop and brain cell replacement slows. ‘The effect is particularly damaging in your 40s and 50s, for reasons that aren’t clear yet,’ he says. ‘Obesity at that age is a marker for cognitive problems later.’
The good news is that this brain-cell damage can be reversed by the two-day fasting regime, although so far Professor Mattson has shown this only in rats. A human trial is starting soon. There is reason to think it should work. Fasting every other day had a striking effect on people with asthma in a small study he ran a few years ago.
Now when Mark Mattson talks about the benefits of fasting, I’ve learned to listen, because he’s always right. Without Mattson, we’d still be thinking daily calorie restriction is the way to lose and maintain a lower weight.
Because of his efforts, we have come to understand the benefits of intermittent fasting (reducing calories only every other day or several days a week) as opposed to every single day (which leads to muscle wastage and biomarkers for disease).
In his studies of fasting and calorie restriction on the brain, Mattson discovered that fasting twice a week can reverse brain damage, prevent neurodegenerative disease, and that this study of the benefits of fasting may one day lead to a cure for Alzheimer’s.
In short, what Mattson is teaching us is that if you want to stay sharp, stay hungry.
Method 2: Calorie restriction of 20 to 30 percent
Calorie restriction (CR), has proven in study after study to have many neuroprotective effects and to enhance memory, cognition, and prevent neurodegenerative decline and brain atrophy.
Among the many brain benefits of engaging in calorie restriction (most dieticians recommend using CR through intermittent fasting or having 4 days of weeks of CR and three days of normal calorie ingestion):
In other words, eating less works great for enhancing brain function.
But, why?
As Mattson adds “considerable evidence from animal and human studies [proves] that high calorie intake is not only bad for your heart, but it’s bad for your brain.”
Mattson adds that
There are several theories about why fasting provides physiological benefits . . . The one that we’ve studied a lot, and designed experiments to test, is the hypothesis that during the fasting period, cells are under a mild stress. And they respond to the stress adaptively by enhancing their ability to cope with stress and, maybe, to resist disease.
Though the word “stress” is often used in a negative sense, Mattson reminds us, taxing the body and mind has benefits, just as exercise causes momentary “stress” but the body reaps myriad benefits it. Mattson adds that “There is considerable similarity between how cells respond to the stress of exercise and how cells respond to intermittent fasting [and calorie restriction].”
Moderate calorie restriction is proving to have myriad beneficial effects from prolonging life and for preventing a multitude of chronic diseases.
Intermittent Fasting
Intermittent fasting (IF) is a way of eating with a goal of restricting the times one consumes daily to a 6 to 8 hour window, leaving the body in a state of fasting longer, much like we do while we’re sleeping as long (as we don’t nosh too close to bedtime or after).
Studies show that IF increases synaptic plasticity, promotes neuron growth, decreases risk of neurodegenerative diseases, and improves cognitive function according to the Society for Neuroscience.
During fasting, a metabolic shift lowers the body’s leptin levels, a hormone produced by fat. As a result, the brain receives a chemical signal for neurons to produce more energy.
Popular forms of intermittent fasting (and most fasters cycle different fast times) include 10, 12, and 16 hour fasts, although some proponents of IF also advocate a one day a week complete 24 hour water fasts as well.
Studies show that intermittent fasting has fantastic benefits for helping us grow lean and strong physically as well, such as
Intermittent fasting (IF) and benefits for cognitive health include that it
Overall, I think you’re beginning to see that both calorie restriction and intermitting fasting can have massively beneficial effects on brain health. For more on this, see this excellent article by Mark Sisson.
Plug DHA and neurodegeneration into Pub Med and it will light up like a New York city street. That’s because study after study is proving the neuroprotective aspects of DHA upon the brain.
DHA enhances the brain’s production of an important substance of BDNF, brain derived neuroprotective factor which is responsible for protecting brain cells and instigating new brain cell growth.
In a recent study of 485 older individuals age 70 and up with mild to moderate memory problems, supplementing with DHA lead to such vast improvements on test scores that lead researcher Dr. Karin Yurko-Mauro noted that “The benefit is roughly equivalent to having the learning and memory skills of someone three years younger.”
Method Two: Exercise, Exercise, Exercise
ATTENTION: Exercise actually creates new brain cells. Did you know that?
And it does a lot more than that for your brain.
Studies have proven that exercise can halt and reverse the kind of brain atrophy we begin to suffer in our 40s and onward (especially in the regions for memory and higher cognitive function), that it increases the volume of neurons in the brain and the white matter (the connections between neurons), and exercise also increases blood flow to the brain, creating biochemical changes that spur on a conditioned that we want (and discussed earlier) called neuroplasticity.
Because exercise increases blood flow to the brain, it also releases something called nerve growth factor which helps the brain to strengthen connections between neurons and create new connections with other neurons.
This is why exercise is at the top of my list for brain strengthening. It is important to note that it must be aerobic exercise and you must engage in at least 3 30-60 minute sessions a week to experience the benefits. Even walking works—any kind of aerobic exercise.
To name just one of thousands of studies (I have given you a clickable bibliography full of great articles on exercise and neurogenesis below!) proving the cognitive benefits of exercise, a recent comprehensive review of 18 scientific studies into the benefits of exercise for brain health found that physical fitness training drastically increases cognitive performance in healthy adults between the ages of 55 and 80.
Another study by Heyn found that even for 65-year old dementia patients, exercise helped them to begin showing major signs of cognitive improvement.
But I think the benefits of exercise for brain health are best summed up by my buddy
Scott Dinsmore, author of the book and blog Live Your Legend: Change the World by Doing Work You Love
While on a boat with Richard Branson, a man asked “How can I be more productive?”
Keep in mind, Richard is the founder and operator of a 400-company conglomerate. He also has dyslexia and a pretty piss poor academic track record.
Yet somehow, from space travel to deep sea exploration, to corporate music and cell phones, this guy has literally been able to accomplish a bazillion times more than the average Joe. And he’s still only 61.
Hence, the crowd of boat passengers hung on the edge of their seat cushions in anticipation of what turned out to be an unbelievably simple answer…
Richard responded: “Work out.”
Among the four methods of enhancing neuron growth and strengthening, “environmental enrichment” sounded the most curious to me. So I studied up on this one.
For animals, environmental enrichment simply means to change up their scene and get them out of the cage, as staying in the cage, because they’re in the same place all the time, leads to mental degradation from lack of stimuli.
So museums, challenging conversation, games of chess with another person, and, specifically activating your “shock and awe” mechanisms all can have an overall positive effect on the brain.
Ideally, we know from studies with animals that
Complex or novel environmental conditions can provide high sensory, cognitive and motor stimulation and increase both hippocampal neurogenesis and the integration of newly born cells into functional circuits At the behavioural level, enrichment enhances learning and memory, reduces memory decline in aged animals and decreases anxiety. (See Paylor et al., 1992; van Praag et al., 1999).
If we don’t exercise the new neurons we grow, more than half of them will undergo a cell death within two weeks after birth.
As researchers note (underlining mine),
New neurons are produced each day in the hippocampus through the process of neurogenesis. Both mental and physical training can modify this process by increasing the number of new cells that mature into functional neurons in the adult brain . . . . Regardless of how many cells are generated, approximately half undergo programmed cell death one-to-two weeks after their birth. In other words, even though many new cells might be produced in response to some environmental manipulations, a great number of those do not survive beyond a few weeks, and they typically die before they have become functionally connected with other neurons in the adult brain. However, in a series of studies, we have reported that most of these new cells can be rescued from death by mental training.
Although scientists are still hard at work studying the kinds of mental training that will result in our keeping (for certain) the new neurons we grow, it is likely that math problems, crossword problems, reading, logic puzzles, and these kinds of mental exercises are all going to be promising – as long as you are working at a level that is mentally challenging for you. That is an important factor here.
What researchers know so far from animal studies is that “Overall, the data suggest that the new cells are most engaged when the task demands are high and mastering them depends on cognitively flexibility.”
By cognitive flexibility here they are talking about their maze studies, for example, with rodents—which require mental flexibility.
These scientists concluded, however, that physical and mental exercise are equally important in growing and sustaining new neurons, adding that
Both manipulations [physical and mental exercise] can increase cognitive performance in the future, some of which are reportedly mediated by the presence of new neurons in the adult hippocampus. Based on these data, we suggest that a combination of mental and physical training, referred to here as MAP training, is more beneficial for neuronal recruitment and overall mental health than either activity alone.
The four methods I’ve discussed above are the methods neurogenesis researchers have found that do grow new neurons and strengthen connections between neurons—in short, help us to get smart.
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Below, and next week, I’ll share more things I am learning about that are key in achieving a maximal brain and may also be some not-yet-discovered ways of stimulating neurogenesis as well—we are all still learning about this, you know!
Insulin is the hormone that causes brain aging. In fact, insulin has such a powerful neurodegenerative effective upon the brain that scientists are now calling Alzheimer’s “diabetes type 3.”
The link between diabetes and Alzheimer’s disease is strong as is the link between insulin resistance, that stage of pre-diabetes before full blown type II diabetes, which is caused by obesity, too many refined starches, and, of course, the demon—sugar.
Folks, there’s just no good reason to have sugar in our diets anymore, in any fashion.
Eat clean.
In fact, Dr. Mark Hyman calls insulin resistance “diabesity,” reminding us that it comes from eating too many carbs, too much sugar, and not enough high health fat (think avocados, eggs, and coconut oil). This state of diabesity, as Hyman notes,
is one of the major factors that starts the brain-damage cascade, which robs the memory of over half the people in their 80s, leading to a diagnosis of Alzheimer’s disease. But don’t think too much insulin affects only older folks’ memories. It doesn’t just suddenly occur once you’re older. Dementia actually begins when you’re younger and takes decades to develop and worsen. Here’s the bad news/good news. Eating sugar and refined carbs can cause pre-dementia and dementia. But cutting out the sugar and refined carbs and adding lots of fat can prevent, and even reverse, pre-dementia and early dementia.
In other words, if you eat a lot of sugar and carbs or are obese and eating sugar and carbs, cut it out now, for the sake of your intelligence and to prevent Alzheimer’s and dementia.
For more on Hyman’s theories about the healthy-fat brain connection, his book Eat Fat, Get Thin covers all of this.
The blood in our brains thickens when we are dehydrated, slowing the function of important neurotransmitters and chemical signals that need to fire in our brain more rapidly, not more slowly, if we want to be ultimately brain-y.
Drinking enough of the right kind of fluids is absolutely crucial for maximizing your brain’s full potential.
But what most people do not know is that they’re going through most every day of their lives dehydrated. Many do not find out until they have a urinalysis for something else.
It’s very important that we drink enough water and electrolytes every day to keep our brains hydrated and fueled.
If you’re thirsty, you are already dehydrated—and never exercise without water handy.
Exercising without hydrating can cause immediate shrinkage of the brain and the sooner you rehydrate the sooner the brain can repair itself.
Almost all electrolytes are important to the health of the brain as well. A good, low calorie way to stay hydrated and replace electrolytes is coconut water.
What foods are anti-brain? The ones you only eat if you’re not using yours!
Sugar, fast food, trans-fat loaded foods that lead to inflammation—packages, processed foods, gluten-y foods, high glycemic index foods that cause a spike and then a drop in blood sugar. Also, dairy and synthetic sweeteners can also cause inflammation.
Sleep helps the brain to reset and to dump all the cognitive garbage you acquire all day. Not only that, late stages of sleep are when the body and brain repairs from exercise, burns fat, and recharges for the day. As researchers from a 2015 study note,
Sleep has been proven to improve memory recall, regulate metabolism, and reduce mental fatigue . . . Each phase of the sleep cycle restores and rejuvenates the brain for optimal function. When sleep is deprived, the active process of the glymphatic system does not have time to perform that function, so toxins can build up, and the effects will become apparent in cognitive abilities, behavior, and judgment.
Additional studies at NYU provide evidences that sleep helps improve our brain’s learning retention capacity by strengthening and growing dendritic spines, which is important for keeping us smart because these dendric spines are responsible for strengthening the connections between synapses as well. And if they don’t connect—they cannot fire, making us the Einsteins we want to be.
Conclusion
We are finally on the path to finding new ways to become smart that, ironically enough, don’t have to rely on the invention of a real-world NZT.
What is really wonderful about all of this though is that it seems to be hinting that we may be on a firm path toward curing Alzheimer’s disease or at least preventing it.
Next Week:
How to Maximize Your Brain Power and Enhance Neurogenesis Beyond Belief—Part 2
Thanks,
Jackson Litchfield
I’m gathering a bibliography of some of the best articles on neurogenesis—ones that are highly readable as well. Enjoy!
Great External Links (The PBS Documentary is fascinating!)
PBS: Changing Your Mind – Grow Your Own Brain
Concise introduction to neurogenesis Wellesley College
Comprehensive website on neurogenesis from Lafayette College
Neurogenesis in adult brain – Fred H. Gage and Henriette van Praag
Scholarpedia Article on Adult Neurogenesis
“TRENDS in Neurosciences, 10 October 2001 (Michael S. Kaplan MD, PhD)
New York Times: Studies Find Brains Grow New Cells
Michael Specter: Rethinking the Brain – How the songs of canaries upset a fundamental principle of science
The Neurogenesis Experiment – Article series on adult human neurogenesis
Seed magazine: The Reinvention of the Self – A historical background on the field of neurogenesis and implications of this research
BBC Radio 4: The Memory Experience – Use it or Lose it
Lobes of Steel: Aerobic exercise appears to promote neurogenesis, New York Times, 19 August 2007
Bibliography of Great Articles on Enhancing Neurogenesis Through Behavioral Modification
Creer, D. J., et. al. (2010. Running enhances spatial pattern separation in mice. Proceedings of the National Academy of Sciences, 107:2367–2372. http://www.pnas.org/content/107/5/2367.full
Curlik, D. M., et. al. (2013). Training your brain: Do mental and physical (MAP) training enhance cognition through the process of neurogenesis in the hippocampus? Neuropharmacology 64:506–514. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3445739/
Kempermann G (2012) New neurons for “survival of the fittest.” National Review of Neuroscience. 13:727–736. https://www.ncbi.nlm.nih.gov/pubmed/22948073
Kronenberg, G. et. al. (2006) Physical exercise prevents age-related decline in precursor cell activity in the mouse dentate gyrus. Neurobiology of Aging. 27:1505–1513. https://www.ncbi.nlm.nih.gov/pubmed/16271278
Shors, T. et. al. Mental and Physical (MAP) Training: A Neurogenesis-Inspired Intervention that Enhances Health in Humans. Neurobiology of Learning and Memory. 115: 3–9
http://www.sciencedirect.com/science/article/pii/S1074742714001580
van Praag H., et. al. (2009). Exercise and the brain: something to chew on. Trends in Neuroscience. 32(5): 283-290. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2680508/
van Praag H, Christie BR, Sejnowski TJ, Gage FH (1999) Running Enhances Neurogenesis, Learning, and Long-Term Potentiation in Mice. Proc Natl Acad Sci USA 96:13427–13431. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC23964/
Yau, Suk., et. al. (2014). Physical exercise-induced hippocampal neurogenesis and antidepressant effects are mediated by the adipocyte hormone adiponectin, Proceedings of the National Academy of Sciences of the United States of America. 111(44): 15810–15815.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4226125/