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How does alcohol affect your brain?
Explore how alcohol affects your brain, from the first sip at the bar to life-long drinking habits.
- Alcohol is the world's most popular drug and has been a part of human culture for at least 9,000 years.
- Alcohol's effects on the brain range from temporarily limiting mental activity to sustained brain damage, depending on levels consumed and frequency of use.
- Understanding how alcohol affects your brain can help you determine what drinking habits are best for you.
Alcohol has enjoyed a near universal presence across human societies. Our ancestors began experimenting with alcohol fermentation at least 9,000 years ago and incorporated such heady drinks into their ceremonies, celebrations, social gatherings, and even medical practices. Today, alcohol is the most popular drug in the world. We use it to destress, to cheer us up, and to lubricate social interactions.
But why have people across cultures and through the ages enjoyed alcohol so much? It's all in how alcohol interacts with the human brain.
To see how alcohol affects the brain, let's perform a little thought experiment. Imagine you're at your favorite haunt, and you order a drink. It doesn't matter if it is wine, beer, or a cocktail. As far as our brains are concerned, alcohol is alcohol is alcohol. (Our waistlines, however, have another opinion on the matter.)
You ease into the booth, have a few sips, and enjoy some chitchat. You polish off your drink as a sense of relaxation disperses across your consciousness. Here's what's going on inside that head of yours.
To get to the brain, alcohol must first be absorbed into your body through the GI tract. Most of the booze will be sopped up by your small intestines, where epithelial cells send it into the bloodstream. If you are drinking on an empty stomach, the alcohol beelines to the small intestine, and you'll feel its effects wash over you quite suddenly.
But if you enjoyed some pub grub with your drink, you'll notice the effects take longer to hit you. That's because your pyloric sphincter is closed to allow the stomach to digest the food. While your stomach absorbs some of the alcohol, it can't manage the job as effectively as your intestines.
Once in the bloodstream, the alcohol moves throughout your body. Your liver begins metabolizing what alcohol it can, but it can only manage so much at a time. On average it can handle one standard drink per hour, but this rate is highly dependent on you as an individual. Some people process their alcohol faster, others slower.
For the record, the United States health organizations measure one standard drink as 1.5 ounces of distilled spirits (at roughly 40 percent alcohol by volume, or ABV), 5 ounces of wine (at roughly 12 percent ABV), and 12 ounces of beer (at roughly 5 percent ABV).
Since you are drinking out, you'll need to pay attention to how much you've consumed in standard measurements. If you ordered a pint of your favorite IPA, for example, you probably consumed 16 ounces of beer at 7.5 percent ABV. You ordered one drink, but your liver is handling closer to two standard drinks.
But hey, it's the weekend, and you decide to belly up to the bar and order another round.
At this point, you're consuming alcohol faster than your liver can metabolize it, and the excess is accumulating in your bloodstream, increasing your blood alcohol concentration (or BAC). As the alcohol rides your bloodstream, it eventually makes its way to your brain, where it passes the blood-brain barrier and begins interacting with your neurons.
How alcohol affects your brain
Women wearing Bavarian folk dresses and headwear enjoy beer during Oktoberfest.
(Photo by Sean Gallup/Getty Images)
Alcohol inhibits activities in the brain. This is why it is known as a "depressant" — not because it makes you feel dispirited but because it reduces, or depresses, mental processes (compared to stimulants like caffeine that increase them). It manages this feat by tweaking with your brain signals.
Put simply, your nervous system relies on two types of signals: excitation and inhibition. Think of them as your personal binary code. An excitatory signal tells a neuron to fire up; an inhibitory signal tells a neuron to stay sedate. Chemical messengers called neurotransmitters are responsible for these signals. Glutamate and GABA are the primary neurotransmitters for excitatory and inhibitory signals, respectively.
As you're enjoying your second drink, the alcohol is hindering your glutamate neurotransmitters while pumping up the GABA. Basically, it's telling your brain to chill out, and you perceive this mental inactivity as a drowsy, easygoing relaxation.
The alcohol is also increasing your brain's output of dopamine, another neurotransmitter that serves many functions, one of which is to control your brain's reward center. A sensation or experience that releases dopamine tells your brain, "Hey, this is going to feel good. Remember this experience because we'll want do this again sometime."
Dopamine is why we experience drinking as fulfilling and also why it can prove habit forming. One study showed that people with a family history of alcohol abuse release more dopamine than nondrinkers simply in expectation of a quaff.
At this point the chemical pickling process has intensified, and your mental inactivity starts to affect the various structures of your brain. As these brain structures switch from active to less active, you feel a variety of different effects.
Your prefrontal cortex, for example, is your mind's executive and plays key roles in decision-making, self-management, and social behavior. As this region's activities slow down, you'll find you are more socially adventurous but also less cautious and prone to impulsive decisions.
Alcohol impairs your cerebellum, which regulates balance and motor functions. The more you drink the more you must concentrate to perform motor functions as basic as walking. A cock-eyed cerebellum also stifles your reaction time and is the reason why drinking and driving is so dangerous.
Then there's the hippocampus, the brain's hard drive. Even small amounts of alcohol can make memories slippery to hold on to. Drink enough and you'll find large portions of the evening's events completely wiped.
Two (or more) drinks over the line
Depending on how much you drink, you can end up anywhere from squiffy to chemically inconvenienced to full-on drunk. But these are only the short-term effects. Alcohol can continue to alter your mind well beyond your morning hangover.
The brain is an incredibly adaptive organ, so the more often you drink the better it learns to compensate for alcohol's effects. This is why long-time drinkers have to drink more to maintain the same buzz. Drink heavily enough for long enough, and your brain's compensation will shift into normalcy, resulting in alcohol dependence. So, the more often you drink the more severely alcohol changes your brain.
Light drinking can be part of a healthy lifestyle and may even confer some health benefits. One study found that light drinkers — those who consume less than three drinks per week — have a lower risk of cancer than moderate to heavy drinkers and even nondrinkers. Of course, the researchers warn that the "evidence should not be taken to support a protective effect of light drinking," so teetotalers needn't get their drink on just to mitigate their risk of cancer.
Moderate drinking — one drink a day for women, two for men — can also be part of a healthy lifestyle, but some research has suggested that even this rate of consumption can have ill health effects. One study found that moderate drinkers were more likely to develop hippocampal atrophy.
Heavy drinking, on the other hand, is undeniably harmful to your body and brain. Such levels of consumption can impact your cognitive abilities and lead to diminished gray matter, memory loss, loss of visuospatial abilities, and Wernicke-Korsakoff syndrome. Heavy drinking quite literally shrinks your brain.
Talk with your doctor
It's worth pointing out that our little thought experiment provides a general overview of how alcohol affects the brain. As with any drug, many factors influence how things shake out, such as a person's age, gender, genetic background, drinking history, and even level of education. Lifestyle choices such as whether you smoke or get enough exercise will also play in.f
Studies have suggested, for example, that women who are heavy drinkers are more vulnerable than men at developing cirrhosis, nerve damage, and brain damage — even if they engage in such levels of consumption for fewer years.
If you choose to drink, the best way to determine what habits are best for you is to speak openly and honestly with your physician.
So much for rest in peace.
- Australian scientists found that bodies kept moving for 17 months after being pronounced dead.
- Researchers used photography capture technology in 30-minute intervals every day to capture the movement.
- This study could help better identify time of death.
We're learning more new things about death everyday. Much has been said and theorized about the great divide between life and the Great Beyond. While everyone and every culture has their own philosophies and unique ideas on the subject, we're beginning to learn a lot of new scientific facts about the deceased corporeal form.
An Australian scientist has found that human bodies move for more than a year after being pronounced dead. These findings could have implications for fields as diverse as pathology to criminology.
Dead bodies keep moving
Researcher Alyson Wilson studied and photographed the movements of corpses over a 17 month timeframe. She recently told Agence France Presse about the shocking details of her discovery.
Reportedly, she and her team focused a camera for 17 months at the Australian Facility for Taphonomic Experimental Research (AFTER), taking images of a corpse every 30 minutes during the day. For the entire 17 month duration, the corpse continually moved.
"What we found was that the arms were significantly moving, so that arms that started off down beside the body ended up out to the side of the body," Wilson said.
The researchers mostly expected some kind of movement during the very early stages of decomposition, but Wilson further explained that their continual movement completely surprised the team:
"We think the movements relate to the process of decomposition, as the body mummifies and the ligaments dry out."
During one of the studies, arms that had been next to the body eventually ended up akimbo on their side.
The team's subject was one of the bodies stored at the "body farm," which sits on the outskirts of Sydney. (Wilson took a flight every month to check in on the cadaver.)Her findings were recently published in the journal, Forensic Science International: Synergy.
Implications of the study
The researchers believe that understanding these after death movements and decomposition rate could help better estimate the time of death. Police for example could benefit from this as they'd be able to give a timeframe to missing persons and link that up with an unidentified corpse. According to the team:
"Understanding decomposition rates for a human donor in the Australian environment is important for police, forensic anthropologists, and pathologists for the estimation of PMI to assist with the identification of unknown victims, as well as the investigation of criminal activity."
While scientists haven't found any evidence of necromancy. . . the discovery remains a curious new understanding about what happens with the body after we die.
Metal-like materials have been discovered in a very strange place.
- Bristle worms are odd-looking, spiky, segmented worms with super-strong jaws.
- Researchers have discovered that the jaws contain metal.
- It appears that biological processes could one day be used to manufacture metals.
The bristle worm, also known as polychaetes, has been around for an estimated 500 million years. Scientists believe that the super-resilient species has survived five mass extinctions, and there are some 10,000 species of them.
Be glad if you haven't encountered a bristle worm. Getting stung by one is an extremely itchy affair, as people who own saltwater aquariums can tell you after they've accidentally touched a bristle worm that hitchhiked into a tank aboard a live rock.
Bristle worms are typically one to six inches long when found in a tank, but capable of growing up to 24 inches long. All polychaetes have a segmented body, with each segment possessing a pair of legs, or parapodia, with tiny bristles. ("Polychaeate" is Greek for "much hair.") The parapodia and its bristles can shoot outward to snag prey, which is then transferred to a bristle worm's eversible mouth.
The jaws of one bristle worm — Platynereis dumerilii — are super-tough, virtually unbreakable. It turns out, according to a new study from researchers at the Technical University of Vienna, this strength is due to metal atoms.
Metals, not minerals
Fireworm, a type of bristle wormCredit: prilfish / Flickr
This is pretty unusual. The study's senior author Christian Hellmich explains: "The materials that vertebrates are made of are well researched. Bones, for example, are very hierarchically structured: There are organic and mineral parts, tiny structures are combined to form larger structures, which in turn form even larger structures."
The bristle worm jaw, by contrast, replaces the minerals from which other creatures' bones are built with atoms of magnesium and zinc arranged in a super-strong structure. It's this structure that is key. "On its own," he says, "the fact that there are metal atoms in the bristle worm jaw does not explain its excellent material properties."
Just deformable enough
Credit: by-studio / Adobe Stock
What makes conventional metal so strong is not just its atoms but the interactions between the atoms and the ways in which they slide against each other. The sliding allows for a small amount of elastoplastic deformation when pressure is applied, endowing metals with just enough malleability not to break, crack, or shatter.
Co-author Florian Raible of Max Perutz Labs surmises, "The construction principle that has made bristle worm jaws so successful apparently originated about 500 million years ago."
Raible explains, "The metal ions are incorporated directly into the protein chains and then ensure that different protein chains are held together." This leads to the creation of three-dimensional shapes the bristle worm can pack together into a structure that's just malleable enough to withstand a significant amount of force.
"It is precisely this combination," says the study's lead author Luis Zelaya-Lainez, "of high strength and deformability that is normally characteristic of metals.
So the bristle worm jaw is both metal-like and yet not. As Zelaya-Lainez puts it, "Here we are dealing with a completely different material, but interestingly, the metal atoms still provide strength and deformability there, just like in a piece of metal."
Observing the creation of a metal-like material from biological processes is a bit of a surprise and may suggest new approaches to materials development. "Biology could serve as inspiration here," says Hellmich, "for completely new kinds of materials. Perhaps it is even possible to produce high-performance materials in a biological way — much more efficiently and environmentally friendly than we manage today."
Dealing with rudeness can nudge you toward cognitive errors.
- Anchoring is a common bias that makes people fixate on one piece of data.
- A study showed that those who experienced rudeness were more likely to anchor themselves to bad data.
- In some simulations with medical students, this effect led to higher mortality rates.
Cognitive biases are funny little things. Everyone has them, nobody likes to admit it, and they can range from minor to severe depending on the situation. Biases can be influenced by factors as subtle as our mood or various personality traits.
A new study soon to be published in the Journal of Applied Psychology suggests that experiencing rudeness can be added to the list. More disturbingly, the study's findings suggest that it is a strong enough effect to impact how medical professionals diagnose patients.
Life hack: don't be rude to your doctor
The team of researchers behind the project tested to see if participants could be influenced by the common anchoring bias, defined by the researchers as "the tendency to rely too heavily or fixate on one piece of information when making judgments and decisions." Most people have experienced it. One of its more common forms involves being given a particular value, say in negotiations on price, which then becomes the center of reasoning even when reason would suggest that number should be ignored.
It can also pop up in medicine. As co-author Dr. Trevor Foulk explains, "If you go into the doctor and say 'I think I'm having a heart attack,' that can become an anchor and the doctor may get fixated on that diagnosis, even if you're just having indigestion. If doctors don't move off anchors enough, they'll start treating the wrong thing."
Lots of things can make somebody more or less likely to anchor themselves to an idea. The authors of the study, who have several papers on the effects of rudeness, decided to see if that could also cause people to stumble into cognitive errors. Past research suggested that exposure to rudeness can limit people's perspective — perhaps anchoring them.
In the first version of the study, medical students were given a hypothetical patient to treat and access to information on their condition alongside an (incorrect) suggestion on what the condition was. This served as the anchor. In some versions of the tests, the students overheard two doctors arguing rudely before diagnosing the patient. Later variations switched the diagnosis test for business negotiations or workplace tasks while maintaining the exposure to rudeness.
Across all iterations of the test, those exposed to rudeness were more likely to anchor themselves to the initial, incorrect suggestion despite the availability of evidence against it. This was less significant for study participants who scored higher on a test of how wide of a perspective they tended to have. The disposition of these participants, who answered in the affirmative to questions like, "Before criticizing somebody, I try to imagine how I would feel if I were in his/her place," was able to effectively negate the narrowing effects of rudeness.
What this means for you and your healthcare
The effects of anchoring when a medical diagnosis is on the line can be substantial. Dr. Foulk explains that, in some simulations, exposure to rudeness can raise the mortality rate as doctors fixate on the wrong problems.
The authors of the study suggest that managers take a keener interest in ensuring civility in workplaces and giving employees the tools they need to avoid judgment errors after dealing with rudeness. These steps could help prevent anchoring.
Also, you might consider being nicer to people.