Neurogenesis—creating new neurons as we age
Yes, you can improve your brain function as you age. Here’s what you need to know about neurogenesis. At its most basic, neurogenesis describes the process by which new neurons are formed in the brain. We have about 100 billion neurons (what we sometimes call “brain cells”). According to the US National Institute of Neurological Disorders and Stroke, neurons use electrical impulses and chemical signals to give our brains information. For decades, it was believed that the neurons we had at birth were the ones we got for our entire lives. But, beginning in the 1980s and moving forward, research suggests that, yes, we can and do create new neurons as we age. If we pay attention to how this happens and the activities that best support neurogenesis, we may be able to keep sharp as we age and perhaps prevent or delay dementia in our later years. It is good news, indeed, to know that the health of our brains is not controlled solely by genetics or childhood experiences, but also by the choices we make later in life. While the brain and the research are both pretty complicated, the ways we can act are pretty simple, says Bryan Bruno, MD, medical director at Mid City TMS, a New York-based medical centre focused on treating depression.
Just like our bodies need aerobic exercise, so do our brains. “Neurogenesis is the way our bodies create new neurons in the brain, mainly occurring in the hippocampus,” says Bruno. “Many different kinds of neurons are created during this process in embryonic development. And this phenomenon continues throughout our lives.
“Synaptic plasticity is how these neurons talk to each other and help our brains change and adapt to new data. As we age, the brain’s plasticity declines, making it harder to adjust to new information. To maintain plasticity as we age, we must consistently provide stimulus to the brain in different ways.” It boils down to the cliché, he says: “Use it or lose it.”
“It’s cool how analogous our brains are to our muscles,” agrees Cathy Spencer-Browning, a human movement expert and vice-president of programming and training at MOSSA, a group fitness firm.
“Like muscle fibres breaking down and rebuilding to create stronger muscles, our neurons break down, then recover and become stronger and more resilient. Yes, our brain’s anatomy can change when we exercise.”
The blood pumping to the brain during exercise, be it a bike ride, a hike, or even sex, can be a boost for neurogenesis, says Ellen Albertson, PhD, author of Rock Your Midlife (Tiger Wellness, 2021), a book about how best to get your brain in shape in midlife (and beyond).
Bruno and other experts agree that the best way to maintain the brain’s plasticity is to learn something new. Every single day. It doesn’t matter what it is, but it does matter that it is new, because it is about the process, not the product.
If you’ve spent your career as an accountant, learning to use new spreadsheet software probably isn’t going to do much for your grey matter’s plasticity: it already knows how to create formulas in a spreadsheet, even if some of the specifics are different.
But if you haven’t played a musical instrument since you were in the band in elementary school, and you pick up a used guitar at a yard sale and start learning to strum, you might be onto something. It doesn’t matter if you master the chords or even how it sounds. What matters is you are learning.
“If you are already good at it, it would not create as much neurogenesis,” Albertson says, who has a personal practice of drawing flowers every Sunday (the previous owner of her home was a florist, so she has plenty of subject material). She’s getting better because practice does that, and she enjoys the sense of accomplishment she gets from that. But whether or not her drawings are “good” or representational is beside the point. It is the process of learning to draw that helps her brain.
In the Seattle Longitudinal Study, which since 1956 has been tracking how adults change as they age, people who had higher levels of education, knew a second language, and participated in cognitive engagement had lower incidents of dementia or a later onset of dementia.
The Seattle research shows that it is possible both to stay “medically fit,” (in other words, stave off dementia) and perhaps remediate some decline of brain function, too.
There’s not a lot of scientific evidence (at least not yet) that brain games and puzzles and the like are improving your cognitive function (no matter what those apps advertise). But if they’re forcing you to use skills you haven’t used before (going back to the accounting example, if most of your life has been number focused), doing a crossword puzzle may fall into the try-something-new category.
Albertson, who is also a registered dietitian nutritionist, says diet plays a role, too. Many experts, including Albertson, consider a Mediterranean diet, high in whole plant foods and occasional seafood, to be a brain-friendly approach.
Look for foods high in omega-3 fatty acids, which can boost memory. Salmon, walnuts, and leafy greens are among the smart (pun intended) ingredients. Foods high in antioxidants, such as (again) leafy greens, plus berries and dark chocolate, can reduce inflammation and slow brain aging, she says.
Because adrenal glands produce and release more cortisol when we’re stressed, more cortisol may have an effect on both memory and cognitive function. A 2020 paper published in the Journal of Neuroscience found that chronic stress can result in a loss of brain synapses related to changes in plasticity.
Aging is beautiful, and more so when we can fully experience it to the best of our cognitive abilities. Fortunately, we can make that happen.
Five brain-boosting herbs and supplements
A member of the mint family, lemon balm may increase cognitive function.
Some believe that extract from this tree may increase blood flow to the brain; the Mayo Clinic says further research is needed.
A small study in Indonesia found that this flowering plant improved cognitive function among stroke patients.
This ancient herb may reduce cortisol and improve memory.
Curcumin, an active compound in turmeric, is an anti-inflammatory and an antioxidant.
Do it daily
Among the research that has come out of the decades-long Seattle Longitudinal Study is that cognitively demanding tasks need to be done every day in order to have a positive effect on brain plasticity. So, set an alarm on your phone, and remember to stretch that grey matter once a day.