Why The Process Of Growing New Brain Cells Is So Damn Important
How the recent death of a close friend showed me the significance of neurogenesis, BDNF and taking mental health very seriously.
Depression Is A Fickle Beast
It’s Tuesday the 4th June which marks exactly one month ago. I’m standing in my kitchen, casually making lunch and following up with some open WhatsApp chats.
As I’m about to finally close the app, suddenly, a new message appears at the top of my screen. It’s a lengthy one, I thought, and coming from a friend of mine that I went to school with and haven’t seen in a year or so.
He tells me that Paul, a mutual friend within our inner circle, took his own life a couple of weeks ago, with the funeral taking place in our hometown within the following days.
A gut-wrenching punch went to my heart and through my whole body.
There I was, blankly staring at the screen of my smartphone. I felt empty and numb inside, struggling to process what I’ve just read. Initially, you‘re kinda trying to convince yourself that it’s just a blatant joke. That someone lost a stupid bet and didn’t think of anything better than that.
However, as the seconds go on, you realize that this one’s real and something irreversible happened. There’s nothing you can really do to prepare yourself for situations like these.
No matter how often you’re faced with the death of someone close to you, it always leaves a scar on you that you’ll have to live with for the rest of your life.
I can’t imagine how painful it must be for parents to lose their child, especially when they were only 22 years old. That has to be a pain like no other.
I immediately booked a flight to my hometown the next morning and embarked upon a journey that would take me to my roots, reconnecting with old places, friends and memories. And giving me some time to reflect not only on past times and the beauty of life, but also the transience of it.
It certainly took me a while to get back into a rational state of mind again, not having to cry each night, just being able to get on with the realities of everyday life. I really don’t know what I’d do without music and my closest friends in times like these. Thank you so much for being there for me!
The Days Pass Slowly, But The Years Fly By
Yesterday marked a special day. I visited Paul’s grave for the first time after the funeral last month. Even though it gives you some comfort that he doesn’t have to go through his pain anymore, it hurts to know that he’s gone, forever. And you’re still asking yourself all the why’s and what if’s, but in the end, it isn’t going to bring him back either.
When I started formulating my ideas for this article back in May, I’d have never thought how personal these topics will become to me. I really had to take a break from everything and started reevaluating the content as soon as I got back into writing.
I knew that Paul faced depression for some time and we casually talked about his experiences with psychotherapy. I learned that he tried out medications temporarily while seeing the psychiatric clinic more as a way to not having to live back home.
Had I but known in how much pain he must have really been.
The last time we’ve met was almost exactly a year ago, when he and another friend of mine came to visit me in my student town. I’ll always cherish these couple of days and memories we had together. You just never know when it’s going to be the last time you see someone important in your life.
Neuroscience’s Take On The Topic
As the weeks passed and life went on, I wasn’t able to get one specific thought out of my head.
What if there’s a way to battle and prevent depression and even mental decline through your diet and lifestyle alone?
It kept me awake at night and I decided to dig deeper into the current state of research behind this specific question.
I know that depression is way more complex than that and consists not only of chemical imbalances in your brain, but has deep psychological roots, too.
Although I’m not a neuroscientist myself, I wanted to try to do the research and find ways to help answer my own question. Above all, imagine if knowledge and the application of it could even act as a preventive measure — that would be equally important.
What It Really Means To Be Depressed
The worst thing about depression is actually the part about losing yourself. Trying to understand your own mind without being able to do so and losing interest in what you once loved. It’s torture in its darkest form, really.
“[…] You don’t want to live, but you don’t want to die. You don’t want to talk to anyone, but you feel very lonely. You wake up in the morning and simply wait for the night to come. It’s like trying to laugh at a joke that isn’t funny. Trying to smile for a photo you don’t want to be in. […]” — A Reddit user
Many people underestimate that part of the self-loathing comes from others as well: Parents making you feel guilty, society giving you the feeling as if you‘ve failed in life because you’re not living up to certain expectations and so forth.
We live in a system that rewards competition and greed — like, if it’s not something that you want to pursue in your life, you’ll somehow feel misplaced. Seeing everyone “succeeding” in life just keeps you in a downward spiral of doubt.
Listen to me — no matter where and who you are, people still care about you, even if you don’t want to believe it, and life will get better.
This one is for you, Paul. I’ll always remember you as the humble, laid-back and honest friend that you were to me.
It’s Just A Matter Of The Hippocampus
The hippocampus is a part of the brain located in the medial temporal lobe. It’s quite well-researched and, for example, one of the first, if not the first region that’s, for example, affected in Alzheimer’s disease in older people.
When talking about depression, it’s interesting to see that one of the things SSRI (“selective serotonin reuptake inhibitors”) drugs, more commonly known as antidepressants, actually do is augmenting the growth of new brain cells in the brain’s memory center.
Neurogenesis (the process of growing new neurons in the brain) is a fundamental player in helping against a decline in memory function, and moreover, plays a significant role in mood regulation as well.
We also know that if there’s decreased BDNF (“brain-derived neurotrophic factor”) circulating in the brain, it strongly correlates with depression as well.
BDNF is a protein produced inside your nerve cells that improves the function of neurons, encourages their growth and protects them against premature cell death. It has actually been shown to be low in people with schizophrenia and depression. This could have major clinical potential, even if it doesn’t sound like much at first.
Science is actually not exactly sure to what extent we can really influence the rate of neurogenesis in a meaningful way. Direct causal evidence linking adult neurogenesis to depression still needs to be thoroughly examined.
Maybe you start realizing now why higher BDNF levels are so helpful — not only for depression, but also when talking about mental decline — it regenerates the hippocampus! And that’s definitely something we want to achieve if we want to maintain our brain health and prevent cognitive disorders or depression.
My overall research is, first and foremost, based on the findings of Dr. Sandrine Thuret and Dr. Brant Cortright. Both of them are brilliant scientists in the fields of neuroscience and psychology who really helped us understand our brain better and looked at different factors that might contribute to a healthier brain function. You’ll find lots of meaningful information in their published papers and books.
Another goodie summarizing a majority of scientific research is also Max Lugavere’s book named Genius Foods. I’m in no way being affiliated or sponsored by anyone, it’s really just a great read if you had to start somewhere.
I had to go deeper, though, and spent literally some days just with research to gather an objective and unbiased perspective on all of these topics.
Where Science Gets Complicated
As someone with a deep interest in optimizing cognitive health and brain function, I am often faced with contradicting evidence when going through scientific papers. Especially in times of pseudoscience and self-claimed experts, it gets more and more difficult to differentiate between all the superficial and easily misinterpreted data out there.
You’ll realize that each variable could have different effects depending on the specific context you’re analyzing it for.
Let’s take coffee for example. I usually drink some cups before each heavy lifting session in the gym every couple of days. My actual goal is to improve not only my focus, but also my performance during my workouts.
According to my 23andMe genome, a polymorphism of my CYP1A2 gene (encodes for the CYP1A2 enzyme which, among others, controls caffeine metabolism) makes the absorption of caffeine extremely efficient in my body.
In addition to that, around 5–6mg of caffeine per kg of bodyweight in general seem to be the peak for enhancing exercise performance which makes for a hefty dose in and of itself. It definitely has its place for performance athletes, but might not be necessary for the average joe.
Coffee also plays a role in regulating Nrf2, a pathway in the body being proven to amplify the production of antioxidants and reduce inflammation. Don’t even let me start raving about how good it tastes.
These are all legit reasons why I love me some coffee.
However, let’s just briefly forget about coffee stain on teeth, occasional caffeine jitters, elevated blood pressure and a couple of other things that are negatively associated with coffee — is caffeine, in our case, beneficial for neurogenesis though? Science doesn’t seem to approve.
Higher caffeine intake may increase focus and concentration in the short-term, but it definitely influences our brain’s function in the long-term by decreasing neurogenesis in the brain. I’ll talk about it in more detail later on.
The consensus is that every human has different goals, therefore, the optimal diet and lifestyle is the one that works for you.
Don’t get me wrong, in no way I’m saying people should or should not drink it – it depends on so much more and, in the end, is completely up to your own preferences.
I just wanted to show you that there are always two sides to an issue and how it helps to be clear about your own intentions when doing something. Talking about opportunity cost and stuff. I evaluated my own reasons and made a conscious decision with my caffeine intake which is what is most important.
So without further ado, here are some scientifically proven factors that influence the rate of neurogenesis, increase BDNF or modulate learning, memory and depressive behavior.
Occasionally decreasing your calorie intake by 20–30% might be one of these things that don’t particularly sound attractive at first, but might positively influence the rate of neurogenesis in the long run.
It gets even more interesting when researchers started looking at how it influenced cognitive abilities when mice and rats were faced with certain tasks. Limiting calorie intake was, for example, associated with enhanced spatial learning in rats and increased learning in mice.
Intermittent fasting, also known as time-restricted feeding, actually shows similar benefits — increased time between meals raises BDNF levels and the rate of neurogenesis, too. If you want to learn more about fasting per se, you can have a look at one of my other articles where I get more detailed with it.
Omega-3 Fatty Acids
If there’s only one dietary choice you could make to help your brain make new neurons, it would definitely be to get more omega-3s into your diet.
Your brain is constituted of 60% by fat, of which 30% are made of the important omega-3 fatty acid DHA (“docosahexaenoic acid”) and around 25% of cholesterol. DHA has been proven to increase neurogenesis in rats.
There’s actually a strong correlation with omega-3 fatty acids and delayed onset of depressive periods in studies being done with people suffering from bipolar disorder. Moreover, higher doses of EPA (“eicosapentaenoic acid”) have also shown a therapeutic effect on depressive behavior, and around 1g of EPA per day were sufficient enough to intervene with bipolar depression.
Fatty fish like wild salmon, sardines or mackerel are king when talking about high omega-3 concentrations. Salmon roe is also another great source, even though it’s a little more pricey. The DHA in salmon roe is actually in its phospholipid form, making it way more bioavailable to your body.
If you don’t like eating fish, you can always supplement with a high quality fish or krill oil.
Many people still tend to recommend ALA (“alpha-linolenic acid”) — which is being found in plant food — as a good source for omega-3 fatty acids.
However, the human body is incredibly inefficient in transforming these into the more important EPA and DHA.
According to the Pauling Institute at Oregon State University, for example, only 8% is converted to EPA and 0–4% to DHA in healthy young men. You’d have to eat lots of calorie-rich foods to gather meaningful doses from it which is just not realistic at all.
Vegetarians and vegans should definitely opt for microalgae oil which is a great source of EPA and DHA, too. That’s actually where all the fish get it from as a matter of fact – by eating algaes.
A good start would be to get at least 1–2g of combined EPA and DHA (not just the total amount of fish oil) per day.
The skin of blueberries is high in phytonutrients called anthocyanins which act as antioxidants in the human body.
They are linked with increased neurogenesis, produce more BDNF and seem to protect against cognitive decline and inflammation, too. Blueberries are also high in tryptophan, which can raise serotonin levels. Serotonin affects concentration and mood to a significant degree.
A daily cup of blueberries, which makes around 100–150g, is usually a good minimum effective dose to implement into your diet.
We all know that exercise is good for your brain, there’s nothing to argue about. It can be extra motivating though to learn the scientific benefits behind it. In one study with rats, Harvard researchers compared resistance training, high intensity exercise training and aerobic training with each other.
The results were that resistance training had virtually zero influence on neurogenesis, HIIT just a little and aerobic training by far the most profound effect on neurogenesis.
Another interesting study done on men between the ages of 18–25 showed that 20–40 minutes of aerobic exercise triggered a 32% increase in BDNF. Thus, we have a natural tool we can use to trigger neuronal upkeep and renewal.
But, as we all know — perfect is the enemy of the good. It’s important to not lose sight of the bigger picture and although aerobic exercise seems to be a little more beneficial when exclusively talking about brain health, HIIT can actually boost the production of BDNF, too.
It’s always a good idea to combine several types of exercise with each other when your goal is to optimize your brain’s function and generally keep your body healthy.
In the end, lifting weights is as good as running or yoga are for different aspects of your health, so just keep your exercise routine varied and balanced!
Curcumin is a powerful anti-inflammatory and antioxidant compound found in turmeric, actually giving curry the yellow color.
On the other hand, however, more is not always best — high doses seem to impair cognitive abilities. A lot of studies use dosages of curcumin around the 500mg mark, assuming it’s combined with something like piperine (can be found in black pepper) to enhance absorption.
Curcumin itself amounts around 3% per weight of turmeric, so if you want to find the right dosage, 3–4 teaspoons per day should be a good start. You can easily use turmeric for cooking.
Now, as mentioned earlier, caffeine is a tough player. Indeed, consumed at low doses chronically, it is known to decrease neurogenesis and elevate cortisol levels which also negatively influences the rate of producing new brain cells in your brain. This is because this stress hormone is meant to make your body redirect all resources towards immediate energy expenditure (fight or flight) as opposed to regeneration and maintenance.
In a nutshell, caffeine seems to decrease neurogenesis.
Interestingly enough, at supraphysiological (extremely high) doses, there is actually an increase in the amount of blast cells, basically being the most immature form of a cell. However, it doesn’t yield an increase in neurogenesis because, in response to caffeine, these neurons tend to have a lower survival rate anyway.
There are some unknowns on why caffeine (important: long-term caffeine intake) could be a detriment to adult hippocampal neurogenesis. People, and even researchers, are insinuating that you should be very careful to not put caffeine on the same level with coffee. The reality is that consuming coffee in comparison to consuming caffeine in its isolated form is very different.
For example, pure caffeine consumption is associated with shorter telomeres in the human body, while coffee consumption is associated with longer ones. On the other hand, chlorogenic acid in coffee is known to boost neurogenesis, and there are some studies showing that coffee boosts Nrf2 levels in the brains of rats and might also be neuroprotective in multiple models of dementia in the short term — through mechanisms which are different than just increasing neurogenesis or BDNF.
The compounds in coffee, more precisely the polyphenols, likely offset a majority of the negative effects of caffeine.
It’s quite similar to how there seems to happen a natural neutralization between resveratrol (a polyphenol positively correlating with neural plasticity) and ethanol when consuming red wine.
Even though alcohol is detrimental to the growth of new neurons, red wine in moderation seems to be a bit of an exception because of its contents of resveratrol, making it a “neurogenesis-neutral” drink. Anyway, take this one with a grain of salt, alcohol remains extremely unhealthy.
Bringing us back to the topic, we now know that caffeine doesn’t necessarily equal coffee and that it might be much wiser to consume caffeine from natural sources like coffee, tea or raw cacao than in isolation.
Actually, you could also switch to decaf coffee which might resolve a majority of caffeine-related problems, while still giving you most of the benefits of regular coffee.
You might also want to include green tea in your diet to benefit from the effects of the polyphenols EGCG and l-theanine — both of which also promote neurogenesis and increase BDNF levels — even if it comes with a standardly low dose of caffeine. Moreover, l-theanine probably has some efficacy in preserving BDNF when administered with caffeine together, too.
When brewed from loose tea leaves, gyokuro and sencha were tested with the highest amounts of EGCG. Matcha is also a great option because you’re consuming the whole leaves with your tea.
If you don’t like drinking tea or are extremely sensitive to caffeine, you can also switch to caffeine-free green tea extract pills which should contain at least 45% EGCG though.
What matters is the EGCG in the green tea extract and recommendations are to not exceed 300mg of total EGCG per day.
I really hope that this article makes you think and contemplate a bit about life and that you were able to get at least a small nugget of knowledge out of it. One of my goals is also to encourage readers to increase their awareness towards depression and mental health, so people would finally treat these with the seriousness they really deserve.
Never ever shy away from starting therapy or calling one of your local suicide prevention hotlines if the feeling of inner restlessness overwhelms you — the girls and guys there would love to listen to you!
And hey, feel free to leave me an email if you just need someone to talk to, I always have an open ear. Sometimes, it might be even easier to share your thoughts with a stranger — who knows, every friend you have was once a stranger too, right?
I also found it extremely helpful to listen to Jordan Peterson’s thoughts on the topic of depression. Being a clinical psychologist from Canada, he helped a lot of people becoming better in many ways — just be warned that it’s quite an emotional video. It absolutely broke me seeing him cry.
If you have anything on your mind, let me know about it! Wherever you might be — stay happy and healthy.
Update, September 2019: Just recently, a really cool documentary about our food intake and its influence on our brain health made its way to the masses. If you’re able to understand German, there’s really a lot to learn from it! I’ll embed it down below!