In 2014, a report in the psychiatry journal JAMA claimed that pornography is actually shrinking your brain. But the study's author, psychologist Simone Kühn, suggested the findings were inconclusive, writing, "It's not clear ... whether watching porn leads to brain changes or whether people born with certain brain types watch more porn."
It left the world with bated breath: Can we watch porn without devolving into slobbering, brain-dead zombies, or what?
The jury's out on pornography. But a lot of other things are actually wreaking havoc on that incredibly complex pile of tissue in your skull. And very few of them have anything to do with butts.
First, hang on. Brain shrinkage? Really? Yep. It refers to a lower volume of gray matter. That means fewer mental resources used for memory, attention and language. We may not know whether the connection between porn and brain shrinkage was correlation or causation, but we do know that having lower volumes of gray matter is an actual problem. Shrunken brains are also shown in people with antisocial personality disorder, and were found in people with long-term alcohol addiction.
Even worse is what happens to your brain when you have alzheimer's or chronic traumatic encephalopathy, the disease at the forefront of the new Will Smith movie Concussion. What happens in your head here is scarier: The "loss of short-term memory, loss of [smell] and personality changes — impulsivity, for example — and then perhaps a loss of motor memory," Kim Gorgens, an associate professor at the University of Denver's Graduate School of Professional Psychology, told Mic.
There are a bunch of things we do every day that screw up our heads. Here's a short list.
1. Abusing alcohol
Alcohol and drug addiction are both physically injuring your brain, specifically in the frontal lobes. The frontal lobes are where you do all of your executive functioning, decision making, multitasking, making decisions, putting a rein on your emotions and handling stress.
"When you're sick normally, your brain tells you to get help," Dr. Harold Urschel, author of the book Healing the Addicted Brain, told Mic. "When you have an addiction, the part of the brain that says there's a problem is injured. Addicts are the last people to know there's a problem. It's like Alzheimer's in that you don't know you have it and it gets worse."
What's scary with addiction is it goes deeper than the frontal lobes. It impacts your limbic system in the middle of your brain. It's the control center, telling you not to die or starve. It's also where your sex drive lives, and where dopamine is released. But if an abused substance drops dopamine in there instead of a naturally occurring high, it can short-circuit your system, and instead of running decisions through your frontal lobe, it just reacts.
"If you think of your brain as a computer, your limbic system is an Intel chip," Urschel told Mic. "And addiction is like jamming a screwdriver right into it."
2. Taking ecstasy
"Ecstasy is one of the few drugs that are actually toxic to your brain," Dr. Clifford Segil, a neurologist at Providence Saint John's Health Center in Santa Monica, California, told Mic. "We have receptors that can handle opiates developed by pharmaceutical companies. But ecstasy isn't meant to be received by them, and it actually damages the brain's neurons."
3. Being stressed out
"Stress has a really obvious, intuitive overlap with substance abuse," Gorgens told Mic. "People who report high stress, are depressed or diagnosed with PTSD all share a really common signature brain volume loss in the hippocampus."
Basically, when we have chronic stress, the actual neurobiological toll is an atrophying brain.
4. Skipping breakfast
"People who do not take breakfast are going to have a lower blood sugar level," Dr. Sanam Hafeez, a neuropsychologist and school psychologist based in New York, told Mic. "This leads to an insufficient supply of nutrients to the brain causing brain degeneration over time."
A paper published in 2012 in the British Journal of Nutrition found that memory and attention were improved in adolescents who ate a low-glycemic breakfast, which includes whole-grain breads, oatmeal and other high-fiber cereals.
Eating more than your body needs can contribute to hardening arteries, which makes your brain slower. In fact, according to an article in the Maryland Medical Journal, the only thing that hardens your arteries more catastrophically than overeating is syphilis. Too many sweet or fatty foods can even cause long-term changes in the brain circuits that control your eating behavior, and how they're linked to pleasure receptors.
6. Smoking cigarettes
Nicotine in tobacco stimulates the part of your brain that releases neurotransmitters that influence your mood, appetite and sense of pleasure. But it also raises the risk of stroke, which happens when the blood vessels in your brain break and bleed, potentially causing neurological damage. That's why, in severe cases of stroke, the victim can be paralyzed, permanently weak-muscled, have a hard time speaking or eating, gets confused easily and has poor coordination.
7. Not sleeping enough
Sleep loss, like stress, takes a massive toll on your body. It impairs arousal, attention, brain speed, memory, decision-making and how you act on emotions. "Sleep deprivation is really neurotoxic, and in young adults, their lives are characterized by prolonged sleep deprivation," Gorgens told Mic. "We underestimate the profound impact of sleep disturbance on brain development, and she should be pretty alarmed at that."
8. Staring at your phone all day
"A harmful habit practiced all day long by most of us is the automatic viewing of our phone, without any allowing ourselves to sit with our thoughts," Hafeez told Mic. "Mindless checking of our screens promotes the expectation of immediate gratification and a difficulty handing negative states of mind organically."
9. Not exercising
Your brain needs dopamine, and physical activity is what makes it naturally. Which is tough luck for people who already have low levels of dopamine, because that makes self-motivation — like the kind that drags your ass to the gym — a lot harder, since you need dopamine to get jacked up about things.
"I hate to say it but it's true," Gorgens told Mic. "Cardiovascular activity promotes [brain growth]. But you don't need to train for a triathlon. It's actually just 60 to 120 seconds of elevated heart rate. It shouldn't be a barrier for most people." That can be a lot of things: biking, playing basketball, going for a walk, having sex — all good options for keeping your brain sharp.
10. Not drinking enough water
Given the option, most people would drink juice over water, since water is boring as hell. So hopefully this helps sway the vote: Your brain is mostly water. So when we're dehydrated, the rest of the body sneaks sips from the brain's fluids to keep other physical mechanisms greased up. That means the cells in your brain actually wither and shrink, or press against the skull, causing headaches. "The key is to drink before you feel thirsty," Hafeez told Mic. "Carry a water bottle with you and eat fruits, which are naturally full of water."
What can I do to keep my brain healthy?
Knowing how many ways you can break your brain down, it's important to know what's keeping it performing well. Enter your brain's three knights in shining armor.
According to Gorgens, the only way to actually grow your brain is through neurogenesis or gliogenesis. The former means the generation of neurons, most of which happens before we're even born. The latter creates the cells that keep your brain in balance, protecting the neurons in the central nervous system away from harm. "Genesis," by the way, literally means production.
But neuroplasticity is where behaviors either live or die. You might hear a doctor say, "All of our brains are plastic." What medical professionals mean is that the brain's always changing, contrary to a 20th-century belief that neural pathways were fixed after birth. What's actually happening is, every time you adapt and get better at something — whether that be jiu jitsu, guitar, Sudoku, whatever — your brain creates new pathways. If it stayed the same, like neurobiologist Santiago Ramón y Cajal believed, you'd never get better at anything.
But the flip side is you can screw your neuroplasticity. In fact, as you get older, your brain does what's called synaptic pruning, a literal "use it or lose it" process that means your brain strengthens the connections you use most and lets the less-used ones, like vocab from high school French, die a lonesome death.
If you finished reading this list and felt washed over with despair, don't worry. There are plenty of things you can do to keep your brain running like a machine. Most of them involve doing something new. Learning an instrument, reading a book you've never read, learning a dance — basically, go have as much fun as possible doing things you've never done before. Your brain will thank you for it.