Neurogenesis is the process of making new brain cells. It used to be though that the brain stopped making new cells once we’re in our early 20’s or so, and after that it was just one slow death. They discovered that we make new brain cells throughout our entire lifetime, and they didn’t know what the meaning of this was until just a few years ago, but it turns out that your rate of neurogenesis is probably the most important biomarker of brain health.
The low rate of neurogenesis is associated with cognitive decline, with memory problems, with anxiety, with stress, and with depression, even lowered immunity.
The high rate of neurogenesis is associated with cognitive enhancement, with rapid learning, rapid problem solving and with robust emotional resilience and with protection against stress, anxiety and depression. It turned out that just about everybody can increase their rate of neurogenesis by about 5 times, probable more.
200,000 years ago, the brain got this size in human beings, in Homo sapiens. We didn’t know that individual brain cells existed until a hundred hears ago. So what increases the rate of neurogenesis and what decreases it? These are brand new things…so new that most neuroscientist don’t even know this.
Two Things That Really Decrease the Rate of Neurogenesis
1. Unhealthy fats
When we eat some of these neurotoxic oxidized fats like corn oil, canola, oil, soybean oil, what happen will probably depends on each person, and kind of where the vulnerabilities are in their system. It certainly goes into your bloodstream first and that creates inflammation in your bloodstream. It chews up the inside of your blood vessels, and the brain gets 20% of the blood. Those bad oils begins to degrade the brain right there. Some people will probably feel that emotionally, some people will begin to feel it cognitively, some people will feel it physically, some probably all, all of those in different degrees. So we don’t want to cook with vegetable oils. We want to cook with coconut oil, butter, ghee, lard. We want to avoid fried foods. We want healthy fats, so that means avocados, nuts, grass-fed beef, pastured chicken, wild-caught fish, pastured eggs and dairy.
2. Sugar & carbohydrates
The other big problem in terms of food is sugar and carbohydrate. Right now, it looks like about 80% of the American population is insulin resistant. Higher levels of insulin are toxic to every organ of the body. Glucose produces glycation. It’s a form of accelerated aging. That also degrades every organ in the body.
A good test for everybody to do when they get their yearly physical is called the hemoglobin A1c. That’s like a snapshot of your blood sugar levels over the last 3 months. If it were at all elevated, you’d be well advised to get on a very carbohydrate-restricted diet in order to increase your insulin sensitivity and bring your blood sugar down because you can track cognitive decline and blood sugarlevels just about perfectly. That’s alarming.
How to Increase Neurogenesis
I think of this as a twofold strategy. One is to decrease things that are neurotoxic (that slow down the rate of neurogenesis). The other is to increase those foods and activities that accelerate our rate of neurogenesis.
The book goes into like 25 or 30 different nutrients that increase our rate of neurogenesis. A big one of these are omega-3 fatty acids. Omega-3s are made up of ALA, EPA, and DHA. And DHA is the most important by far for the brain. The brain is made up of about 2/3 fats, and 1/3 of that fat is DHA.
A lot of people take flax oil or chia seed. It turns out that it doesn’t work. So little gets converted to DHA, because that’s strictly the ALA form, and something like 5% of less gets converted. However, if you are a vegetarian, there’s a new form of algae-derived, which is EPA. That does convert to DHA. So if you’re vegetarian, you have to get the algae form of omega-3s. That will convert and actually raise the blood level of DHA.
It takes between 4 and 6 and 8 weeks for new brain cells to mature and come online. So that’s why antidepressants take 4 to 6 to 8 weeks to work. It used to be believed that antidepressants worked though increasing your levels of serotonin. There’s this whole serotonin deficiency theory that causes depression. It turned out that theory is wrong. And the pharmaceutical companies know it’s wrong. But the way the antidepressants work is that they increase our rate of neurogenesis.
This is how the attention got put on neurogenesis. They discovered that the way antidepressants work is to increase our rate of neurogenesis and that a low rate of neurogenesis is what is involved in depression. So it turns out though that antidepressants only work in less that 50% of the people who take them, and they come with a slew of side-effects, but there are many natural substances, which also increase our rate of neurogenesis without side-effects. There are a number of studies that show that omega-3 fatty acids at about 6 grams a day is actually more effective than SSRIs and than Prozac.
If you do omega-3, you’ll increase the rate of neurogenesis by 40%. However, many of those new brain cells die off pretty quickly, unless you do other things, for example, hesperidin. Hesperidin is a bioflavonoid that appears in citrus fruits. And its main function is to keep new neurons alive. Green tea is another one. The extracted green tea, ECGCs, they are not only an-antioxidant and anti-inflammatory, but they also are like Miracle-Gro for brain cells.
Neurogenesis happens in the hippocampus. Hippocampus is this interesting structure, like a crescent moon, and one end of it is involved in emotion regulation, particularly the emotions of stress, anxiety and depression.
The other end of it is involved in cognition, in memory processing and its spatial relationships and the body. It turns out that SSRIs and all the antidepressants only increase neurogenesis along the emotional side of the hippocampus, so you don’t get a cognitive boost.
Exercise for Neurogenesis
There is good stress and bad stress. Good stress is short term and moderatethat makes us stronger. It brings forth new capacities. We need a certain amount of stress. It’s sort of like exercising. But that’s not the kind of stress that most people suffer from. Most people suffer from chronic stress. An extreme stress can shrink the hippocampus, kill the brain cells that is neurotoxic.
Any type of exercise is good for the body, but when it comes to neurogenesis, it looks like the only kind that’s effective is aerobic exercise. Aerobic exercise is anything that gets you breathing fast and your heart rate up. So running, walking quickly, biking, walking up a mountain, swimming, fast dancing, anything that gets you breathing hard is a very potent stimulator of neurogenesis.
Synaptogenesis is the brain making connections among the different brain cells. It’s how the brain is constantly rewiring itself.
Myelogenesis is creating new myelination. Actually some myelination doesn’t even become fully present until our 50’s or even early 60’s. There are some parts of the brain that don’t achieve full myelination until very late in life. There are some things in terms of fluid intelligence, in terms of rapid learning that decrease slowly starting in our 20’s and 30’s, but there are many other things involving crystallized intelligence, involving empathy, involving planning, emotional regulation, executive function, which don’t even reach their peak until our 40’s and 50’s, some even early 60’s.
Right now, Alzheimer’s is the one disease, according to the Alzheimer’s Association, for which there is currently no treatment, no cure, no prevention, and no drug to do anything. One in three seniors dies with either Alzheimer’s or some other form of dementia.
It looks like right now, a holistic approach is really the only thing that can help prevent or delay Alzheimer’s, because it seems like it’s a lifestyle disease more than anything else. And since it begins decades before we see the symptoms, now is the time to start for all of us. If we can keep the brain young and alive, then the rest of the body will come along.
Source: Bulletproof Radio #287
Foods and Nutrients that Stimulate Neurogenesis - from chapter 3: DIET -
Omega-3 fatty acids (esp. DHA & EPA), extracts from fish oil
Green tea or green tea extract containing the catechin (EGCG)
Curcumin from turmeric
Whole soy food such as tofu, edamame, soy milk, soy nuts, soy isoflavone extracts containing daidzein & genistein
Ginkgo biloba (herbal extract)
Quercetin (found in many foods, sold as an extract)
Grape seed extract
Lotus root extract
St. John's wort
Brant Cortright, Ph.D.
professor of psychology http://www.brantcortright.com
author of ”The Neurogenesis Diet and Lifestyle: Upgrade Your brain, Upgrade Your Life”