Adults Can Grow New Brain Cells: How Neurogenesis Works (Part 2 - Neuro-exercise, touch and sex)


Two main ways to increase neurogenesis are diet and exercise. Exercise increases neurogenesis to four or five times the normal rate. Having said that we need to remember that only 40-60% of the new neurons survive. To increase the 40-60% up to 100% we require an enriching environment.

Brant Cortright in ‘The Neurogenesis diet and lifestyle 2015’ book has a holistic approach where he looks at physical, emotional, mental and spiritual dimensions to understand better what is an enriching environment for humans. The first part focuses on the physical aspects of an enriching environment which are:

–Exercise (certain kinds)


–Sexual experience

–Sleep ( 7 or 8 hours per night)

–Doing new things, being in novel environments, new sensory stimulation

–Music, silence, natural sound



When a running wheel is put into a mouse’s cage, the mouse voluntarily spends time each day running on it, because they enjoy how their body feels while doing the exercise, “The results show that the hippocampus fairly explodes with new neurones’. However a sedentary mouse without a running wheel show no increase in neurogenesis.

When it comes to exercise not all exercise has the same affect. Aerobic exercise has been found to be best for neurogenesis. Whether it’s running, walking briskly, cycling, aerobic dancing, swimming, water running, using stair climbers, cardio classes, soccer, tennis, hiking up mountain, or whatever gets us breathing fast and hard.

There are two main reasons why aerobic exercises contribute to neurogenesis. It reduces a brain protein called BMP (for bone morphogenetic protein) that slows down neurogenesis and keeps neural stem cells in cellular sleep. When new brain cells develop they require blood supplied to help them grow. Aerobic exercise also accelerated the heart so blood gets pumped faster through the body. 

Aerobic exercise can be contrasted to weight bearing exercise, that strengthen muscles (like weight lifting), or stretching exercise, that increases flexibility (like yoga or tai chi). Although this type of exercise have health benefits they don’t seem to increase neurogenesis.

If the thought of exercise is putting you off - the good news is that you can start with just 20-30 min walk three or four times a week. This will bring an aliveness to your life you didn’t know possible.


We are wired for touch. A mother instinctively picks up and holds her baby when it starts to cry. When the baby is distressed and cries, its immature nervous system hasn’t yet learned to self regulate. Touching allows two nervous systems to synchronize and harmonize into a larger, more relaxed state in which both people feel better.

Our bodies and brains hunger for touch as it stimulates the release of oxytocin, the so-called love hormone. Oxytocin reduces stress hormones such as cortisol, lowers blood pressure, increases heart health, boosts immunity, lessens depression, eases fatigue and increases neurogenesis.

A 20 second hug followed by 10 minutes of hand holding has a strong anti-stress response that lowers blood pressure and heart rate. Even 10 second hug each day leads to hormonal and bodily changes that improve health.

The more children are touched growing up, the higher their rate of adult neurogenesis. The more adults are touched, the higher their rate of neurogenesis. Touching is good for us (provided it’s not unwanted or inappropriate). The key is trust. If we trust the person touching or hugging us, oxytocin is released, then we feel relaxed and calm. But if we don’t know or trust the person or if the touch is unwanted, we feel more stress, not less. If we know and trust the person and welcome their touch, it’s good for our brains and unleashes a cascade of health benefits.



As is we had to have another reason to have more sex – but here it is. Not only does sexual experience increase neurogenesis, it also:

  - improves immunity

  - cuts the risk of heart attack in half in men who have sex twice a week or more

  - reduces stress

  - improve sleep

  - lowers blood pressure.

It is important to note that, in human beings sex is tied to emotional experience in a far more complex way then it is for other mammals. As per touch, for sex to be helpful for reducing stress, it needs to be welcome and from someone we trust. Emotional sex trumps the act when it comes to neurogenesis for most people.

Next week we will look at: 


-Doing new things, being in novel environments, new sensory stimulation

-Music, silence, natural sound


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