Your parents were right—at least, kind of right—when they warned you about the consequences of partying too hard. Headbanging, binge drinking, smoking pot, and all the other things you're liable to get into on a Friday night really aren't particularly good for your brain cells. But your mom or dad may also have been a little melodramatic: It's actually pretty hard to kill your brain cells, though you can still do some serious damage.
Let's start with booze. Like other substances, it changes the chemistry of your brain, says Julia Chester, an associate professor of behavioral neuroscience at Purdue University. No, it doesn't outright kill brain cells, but tinkering with your brain chemistry still isn't the brightest of ideas. A few drinks here and there are not an issue for an otherwise healthy adult, but regular benders can do lasting damage. "When you're regularly changing the neurochemistry of the brain, the proteins of the cells start to change," Chester says. Imagine a charger for your cell phone. "It's made up of a set of wires that can get frayed over time," she says. "If you start to break those fibers, the speed at which you can charge your phone decreases. You have less connectivity."
At the extreme end of the spectrum is Wernicke Korsakoff's Syndrome, where extensive alcohol exposure blocks the brain from absorbing vitamin B1. This deficiency can lead to permanent damage—especially in the areas of the brain responsible for memory. If heavy drinking frays your charger, the analogy for Werincke Korsakoff's Syndrome is plugging your phone into the charger and getting zero juice at all.
Research has shown that the effects of alcohol on the brain are especially damning in teens and young adults. Chester says that during adolescence, your brain grows rapidly. Then, from the ages of 18-25, there's further maturation of the prefrontal cortices. Your brain is especially susceptible to damage via, say, tequila shots and beer bongs in these years. "If people waited until they were 21 to start drinking, the brain would be so much more protected. It would be great. In fact, it would probably be best for us not to start drinking alcohol until our late 20s," she says. (Oops.)
Other drugs, however, are even worse. Though they may not outright kill cells, "They change the activity pattern of brain cells and your brain becomes dependent on that activity," says James Giordano, professor of neurology and biochemistry at Georgetown University Medical Center. Over time, "drugs can change a brain's function and can even change aspects of its structure," he adds.
Pot, too, impacts your brain—no matter what your old college roommate tried to tell you. The occasional joint or bong rip won't kill brain cells, but that doesn't make it side-effect free. Yes, humans do have cannabinoid receptors. But when you regularly smoke or ingest marijuana, it can interrupt the production of the chemical (called anandamide), that's supposed to bind with those receptors. Plus, the constant stream of THC may reduce the sensitivity of those receptors.
You're even pretty safe if headbanging happens to be part of your plans tonight—as long as you really, really, don't overdo it. You'd have to go at it pretty hard to actually kill your brain cells, but technically, it can be done: It's not uncommon, for instance, to see "coup" or "contrecoup" damage to the brain after incidences of severe whiplash, like in a car crash or on a roller coaster, Giordano says. "Picture a can filled with fluid—that's the cranial vault. Inside the can is something floating—that's the brain, and it doesn't occupy all the space. As the whiplash happens, your brain is moving inside the cranial vault." If the impact is hard enough, your brain may just smash up against the front or rear of your skull, and blammo, damage happens. How many cells would be affected is impossible to know, and the extent of the damage would depend on exactly how fiercely your brain made contact with your skull. Still, it's worth knowing that you need not have an impact with another object to give yourself a traumatic brain injury.
So why does any of this matter? Because your brain isn't like the rest of your body when it comes to repairing itself. "Like any injury, the brain cells release chemicals that are intended to promote healing but also end up damaging the cells and lead to scarring," Chester says. But where the rest of your body would simply begin regenerating new cells to replace the damaged ones, this healing process is trickier in the brain. Research done in the last decade indicates the brain could produce new cells through a process called neurogenesis. Total cellular regeneration, however, is limited. "In looking at the adult human brain with the currently available techniques, neurogenesis was found to occur in only two areas (the sub-granular zone of the hippocampus, and the sub-ventricular zone around the cerebral ventricles), and nowhere else. There's still some debate as to whether and to what extent this neurogenesis produces any functional effects," Giordano says.
The rest of your gray matter? All it can do is troubleshoot, working to repair damaged parts of the cell and form new connections to other cells. But that leads us to another bit of good news, at least: Your brain has "plasticity," or the ability to remodel a bit as needed. "We are learning about the incredible ways the brain can recover function after an injury. Stimulating the brain with cognitive training tasks or by practicing with virtual realities may help it recover cognitive and motor functions," Chester says. Giordano adds that we often see examples of this in mild to moderate stroke victims, who lose their speech initially but regain bits over time.
Also: You have a lot of brain cells—more than 100 billion, so knocking out a few thousand probably isn't all that bad, Giordano says, adding that there's no way to get an exact count on how many you're offing with every moment of regrettable decision-making. But if you're beginning to look back on your college years and wondering if you'll be a vegetable by the time you're 60, fear not: There are actually things you can do that may help offset the damage.
"The general operating rule of the brain is use it or lose it," Giordano says. Learning new skills—especially things like foreign languages, which force you to use several different parts of the brain at once—will help forge new connectivity. "Healthy body, healthy brain is also a good rule," he says, adding that keeping blood sugar stable, cholesterol low, and engaging in regular exercise all help produce optimal brain health. Finally, make sure you get enough sleep—and, if you haven't already, consider putting down that forty.
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