You Can Prevent Your Brain From Shrinking, Plus 4 Other Brain Facts

Are you speeding up your brain’s decline without even knowing it?

1 / 6

The brain is a highly complex organ in which around 86 billion nerve cells or neurons constantly talk to each other. All that chatter is what makes you cringe when someone steps on your foot, laugh at a joke or remember where you left your phone.

Not surprisingly, different parts of the brain have different jobs. The largest part is the cerebrum (the wrinkles and folds that you probably picture when you think of the brain); it’s covered by the cerebral cortex—what we often refer to as “gray matter.” The cerebrum handles higher brain functions like thoughts and actions; all the folds and wrinkles provide more surface for more information to be processed.

The brain stem is the powerhouse link between your brain and your spinal cord. It controls your heart rate, blood pressure and breathing. And the cerebellum is a wrinkled ball behind the rest of your brain. It helps coordinate movement by working with sensory information from your eyes, ears, and muscles.  

Although the brain is a complex system, researchers have uncovered some fascinating facts—and debunked some myths—over the years.

Medically reviewed in February 2020.

The brain isn’t fully developed until your 20’s

2 / 6 The brain isn’t fully developed until your 20’s

Researchers previously believed that the brain stopped growing by puberty. Now researchers know that the brain continues to develop well into your 20’s. In fact, the frontal lobes, which are imperative for planning and impulse control, are one of the last parts to fully develop. Little wonder you may have made some bad judgement calls in your teen years, like a regrettable tattoo or tongue piercing.

The brain constantly matures and thickens throughout adolescence—specifically the areas responsible for memory, language, creativity and attention.

Gray matter growth peaks at approximately 11 years old for girls and 12 years old for boys. After this stage, the prefrontal cortex, which makes up the part of your brain responsible for judgement, becomes more developed.

Although children already have some impulse control and are able to plan and set goals, over time their ability to use these skills becomes more consistent. So don’t be surprised if you only started to get better at decision-making well into your 20’s.

The brain shrinks over time—and some things can hasten it

3 / 6 The brain shrinks over time—and some things can hasten it

Brain volume naturally shrinks with age at a rate of about five percent per decade after the age of 40. While smaller brain volume doesn’t correlate to a lower IQ, it could indicate cognitive decline. But it turns out that some factors under our control can hasten brain shrinkage.

According to a 2011 study published in Neurology, researchers collected the blood pressure, weight and cholesterol levels of 1,352 adults averaging 54 years old who did not have dementia. They also took MRI scans of their brains. Ten years later, the researchers remeasured the size of the participants’ brains, then had them complete cognitive tests to determine planning and organizational skills.

The researchers found that four factors sped up the decline in brain volume: high blood pressure, diabetes, cigarette smoking and obesity. These same factors increase the risk of heart disease. The results of the study suggest that certain controllable factors can impact cognitive function as we age.

We use a lot more than 10 percent of our brainpower

4 / 6 We use a lot more than 10 percent of our brainpower

With so many books on the market about unlocking untapped brainpower, it’s not surprising that so many people still believe that we only use 10 percent of the brain. The truth is, we use all of it. Even when you think your brain is inactive, such as when you sleep, it’s busily at work, performing functions such as sorting through the details of what happened during the day and committing to memory the important ones.

The 10 percent myth began in the early 1900’s, believed to be the brainchild of a man named William James. James was an influential psychologist during his time, famous for stating that people are capable of using untapped mental potential. The myth held and helped fuel the self-help market, which continues to this day.

Neuroscientists have been working to debunk the myth for years, since we now know that the brain is actively at work at all times. You might want to save your money the next time you receive an offer to unleash more brainpower; it's already firing on all four cylinders. 

There is no left-brain/right-brain personality type

5 / 6 There is no left-brain/right-brain personality type

You might be great at solving complex math problems while your best friend is an amazing wordsmith. But contrary to popular belief, it doesn’t mean that you are left-brained and your friend is right-brained.

The brain is made up of a right and left hemisphere. The left side’s lobes are accountable for speech and the right side for spatial thinking. Despite the two separate hemispheres, there is little to no evidence proving that individual personality traits are determined by one area of the brain.

In a 2013 study from the University of Utah, researchers studied brain scans of more than 1,000 people between the ages of seven and 29 to see if you can be one-side dominant. Researchers then mapped the brain into more than 7,000 individual regions and examined the scans to see which parts of the brain were most active. There was no evidence to prove a more active side, and verified that right-brain or left-brain prominence is a misconception.

Your brain doesn't like the cold

6 / 6 Your brain doesn't like the cold

Have you ever had an extra icy cold drink or ice cream and felt a sudden stabbing pain in your head? Turns out it’s a real scientific phenomenon. The sharp pain can be triggered by two things: exposure to a cold stimulus, such as drinking or eating something extremely cold too quickly, or by exposing your head to very cold temperatures. The term for this phenomenon is sphenopalatine ganglioneuralgia—try saying that with a mouthful of ice cream.

Arteries that feed your brain pass near the back of your throat. These arteries don’t like quick changes in temperature, so when you eat or drink something cold, it causes them to quickly constrict and then dilate. That causes a quick burst of pain in the lining of your brain. “Brain freeze” typically doesn’t last more than a couple of minutes.  

Continue Learning about Brain Health

Best Brain Training: Get Moving
Best Brain Training: Get Moving
For a rock-solid memory and razor-sharp brainpower, get up and move! A growing stack of research confirms that working your brain as if it were a core...
Read More
What does the brain need to work properly?
Eric OlsenEric Olsen
To work at its best, the brain needs a constant supply of oxygen and glucose, which is carried to th...
More Answers
6 Simple and Delicious Foods to Boost Your Brain Health
6 Simple and Delicious Foods to Boost Your Brain Health6 Simple and Delicious Foods to Boost Your Brain Health6 Simple and Delicious Foods to Boost Your Brain Health6 Simple and Delicious Foods to Boost Your Brain Health
Grocery list essentials for a strong mind.
Start Slideshow
What Is Mindsight?
What Is Mindsight?