Your super-efficient digital assistant
There's a reason so many people joke that their smartphones are their "brain"—because it kind of is becoming your brain. Google, Alexa, Siri, and other digital assistants have taken the burden of remembering details off your mind, meaning that your brain misses out on making those connections. Case in point: What's your mom's phone number? Heck, millions of people don't even know their own phone number.
That late-night Netflix binge
We're all chronically sleep deprived these days, and one of the first things to suffer when you lose zzz's is your brain—and it doesn't take much sleep loss to start impairing your mental abilities. "Study after study has shown that even an hour or two less sleep each night for just a few consecutive nights can have negative effects on the brain," says Vernon Williams, MD, sports neurologist and director of the Center for Sports Neurology & Pain Medicine at Cedars-Sinai Kerlan-Jobe Institute.
Your secret junk food stash
Candy, soda, fast food, and other modern inventions are one of the most common (albeit delicious) ways to drain your brain, Dr. Williams says. "One Australian study found that just five days of eating junk food could impair memory function, attention, speed, and mood," he says. "The idea is that poor diet leads to inflammation in the brain, which can damage its structures." Instead, focus on the healthiest foods to eat in every decade of your life.
That gym class you keep meaning to hit
You may think all you're hurting is your waistline, but not getting enough exercise can damage your brain, Dr. Williams says. "Exercise has so many brain-boosting benefits, including a better mood, sharper mental performance, improved memory, and less pain," he says.
All that romantic mood lighting
Keeping the lights low may increase the feeling of ambiance (and make it harder to see the dirt on the floors!), but it won't help your brain, according to a study done by Michigan State. Researchers found that spending too much time in dimly lit rooms and offices may actually change the brain's structure and hurt your ability to remember and learn, especially when it comes to spatial tasks.
Your multitasking lifestyle
Think that you're an excellent multitasker and that doing several things at once makes you smarter? It's likely having the exact opposite effect, says Joe Bates, MD, a psychiatrist and author of Making Your Brain Hum: 12 Weeks to a Smarter You.
The constant notifications on your smartphone
Instead of using our phones as a handy tool we use to help us, many of us are letting technology control us, Dr. Bates says. The constant barrage of texts, emails, voicemails, games, and other alerts is a never-ending distraction, making it impossible to focus and think, he says. "This can turn into an actual addiction by programming the brain to want to keep checking your phone, as it gives you immediate gratification," he explains.
That glass (or three) of wine with dinner
Anyone who's ever had a "deep" conversation with someone who's had a few too many drinks knows how quickly booze can dumb you down. But did you know that overindulging in alcohol also has long-term harmful effects on your brain? "In addition to the possibility of impaired brain function as you age, drinking puts people at a higher risk for liver disease, strokes, depression, and many other diseases that also impair brain function," says Mary Ellen Moore, DO.
Your 9 to 5... or 7 to 9
There is some truth to the old adage "work smarter, not harder." When it comes to maximizing your mental abilities, working too much can have the opposite effect, making you a less creative and less accurate thinker, says Kate Martino, a physician's assistant and weight-loss coach. Just like any other body part, your brain doesn't do well with a lot of stress, and it needs to rest sometimes.
Your workspace at the local coffee shop
You may think that being able to work anytime anywhere is a major job perk, but setting up shop in a noisy environment, such as a coffee shop or airport terminal, could make it harder for you to work. Being surrounded by constant noise impairs the brain's ability to learn new things and hurts your memory, according to a study published in Frontiers of Psychology.
Your morning bowl of cereal
Sugar-packed cereals are no better for you than eating a doughnut, and even "healthy" cereals may be hurting your brain health, Dr. Moore says. "Butylated hydroxytoluene (BHT) is a preservative commonly found in cereal and food packaging that interferes with the signals from your brain," she explains. This includes the satiety signals that tell you you're full, making you not just dumber but also more prone to weight gain, she says.
Your fear of flying (or getting fired or being dumped or ...)
A little angst keeps you alert and moving, but feeling a constant barrage of fear or worry can seriously impact your mental health and your ability to think clearly, says Farah Harris, a licensed clinical professional counselor. "When we are fearful, it is like our brain has been hijacked and we are unable to think rationally, see things clearly, be objective, and recall details," she says.
Your deep dislike of fish
What you eat has a huge impact on how you think, starting with the types of fats you consume, says Rob Cole, licensed mental health counselor and registered dietitian, Clinical Director of Mental Health Services at Banyan Treatment Center. Eating foods high in trans fats, commonly found in processed snacks and fast food, hurts your brain health and has been linked in research to cognitive decline, he says. On the other hand, healthy fats, like those in wild salmon (and also nuts, chia seeds, and avocados), have been shown to protect brain cells and make your brain more efficient, he adds.
Your empty water bottle
Want to know the fastest way to drain your brain? Drain your body of water. Even mild dehydration can have profound effects on your mental capabilities, Cole says. "Drinking enough water is critical to ensure chemical balance in the brain," he explains. Resist the temptation to substitute juice, soda, coffee, or other liquids, as the extra sugar can also impair your brain.
Those reheated leftovers
Plastic dishes are so convenient! Unfortunately, they are also not doing your brain any favors. Bisphenol A (BPA) is a common industrial chemical added to plastics to make them more durable, but the chemical also interferes with brain function by killing neurons, which can lead to mood problems and an impaired memory, according to a study published by the National Academy of Science.
Your pasty white skin
Feeling confused, depressed, and indecisive? A walk in the fresh air and sunshine may be the best remedy. A 2014 study conducted by The American Academy of Neurology found that people with extremely low blood levels of vitamin D were more than twice as likely to develop Alzheimer's disease or other types of dementia than those with normal levels, says Lauren Zimmerman Cook, CEO of AEC Living. Other than soaking in the sun, here are more everyday things that are making you smarter.
Those pesticides you just sprayed on your grass
Call it a side effect of modern living, but we are surrounded by toxins in our air, in our water, and in our food. Unfortunately, these can take a major toll on brain health, particularly as they accumulate over time, says psychotherapist Toni Coleman.
That office lunch you always skip
"Social isolation leads to loneliness, which can have a dramatic impact on your brain," says Bryan Bruno, MD, depression specialist and medical director at Mid City TMS. "Without daily social engagement, the brain loses its ability to stay sharp and experiences a much higher chance of developing dementia. Those suffering from isolation show less neural activity in the brain's ventral striatum, which is part of the brain's reward center and plays an important role in learning."
Your raging sweet tooth
Any foods with added sugar, including "healthy" foods like juice and smoothies, can lead to poor cognitive function in the short term, and Alzheimer's disease or dementia in the long term, says MaryAnhthu Do, MD, a neurologist with the Neurosciences Institute at Advocate Christ Medical Center in Oak Lawn, Illinois. It's OK to have a treat sometimes, just make sure it's a treat and not a staple, she says. And remember, there's just no such thing as a "healthy sugar"—that's one of the 37 myths nutritionists wish would die.
The tablet propped up on your lap
Whether you're constantly on your laptop, refuse to leave without your tablet, or are attached at the hip (literally) to your smartphone, all that tech is taking a toll on your brain, says Michelle Robin, DC, wellness practitioner and chiropractor. "Instead of having downtime and letting our minds wander, we reach for our phone as soon as we have to stand in line, when we do something as simple as walk down the hall, and while we are waiting for a meeting to start," she says.