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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.
The COVID-19 pandemic is making health disparities in the United States crystal clear. It is a clarion call for health care systems to double their efforts in vulnerable communities.
- The COVID-19 pandemic has exacerbated America's health disparities, widening the divide between the haves and have nots.
- Studies show disparities in wealth, race, and online access have disproportionately harmed underserved U.S. communities during the pandemic.
- To begin curing this social aliment, health systems like Northwell Health are establishing relationships of trust in these communities so that the post-COVID world looks different than the pre-COVID one.
COVID-19 deepens U.S. health disparities<p>Communities on the pernicious side of America's health disparities have their unique histories, environments, and social structures. They are spread across the United States, but they all have one thing in common.</p><p>"There is one common divide in American communities, and that is poverty," said <a href="https://www.northwell.edu/about/leadership/debbie-salas-lopez" target="_blank">Debbie Salas-Lopez, MD, MPH</a>, senior vice president of community and population health at Northwell Health. "That is the undercurrent that manifests poor health, poor health outcomes, or poor health prognoses for future wellbeing."</p><p>Social determinants have far-reaching effects on health, and poor communities have unfavorable social determinants. To pick one of many examples, <a href="https://www.npr.org/2020/09/27/913612554/a-crisis-within-a-crisis-food-insecurity-and-covid-19" target="_blank" rel="noopener noreferrer">food insecurity</a> reduces access to quality food, leading to poor health and communal endemics of chronic medical conditions. The U.S. Centers for Disease Control and Prevention has identified some of these conditions, such as obesity and Type 2 diabetes, as increasing the risk of developing a severe case of coronavirus.</p><p>The pandemic didn't create poverty or food insecurity, but it exacerbated both, and the results have been catastrophic. A study published this summer in the <em><a href="https://link.springer.com/article/10.1007/s11606-020-05971-3" target="_blank">Journal of General Internal Medicine</a></em> suggested that "social factors such as income inequality may explain why some parts of the USA are hit harder by the COVID-19 pandemic than others."</p><p>That's not to say better-off families in the U.S. weren't harmed. A <a href="https://voxeu.org/article/poverty-inequality-and-covid-19-us" target="_blank" rel="noopener noreferrer">paper from the Centre for Economic Policy Research</a> noted that families in counties with a higher median income experienced adjustment costs associated with the pandemic—for example, lowering income-earning interactions to align with social distancing policies. However, the paper found that the costs of social distancing were much greater for poorer families, who cannot easily alter their living circumstances, which often include more individuals living in one home and a reliance on mass transit to reach work and grocery stores. They are also disproportionately represented in essential jobs, such as retail, transportation, and health care, where maintaining physical distance can be all but impossible.</p><p>The paper also cited a positive correlation between higher income inequality and higher rates of coronavirus infection. "Our interpretation is that poorer people are less able to protect themselves, which leads them to different choices—they face a steeper trade-off between their health and their economic welfare in the context of the threats posed by COVID-19," the authors wrote.</p><p>"There are so many pandemics that this pandemic has exacerbated," Dr. Salas-Lopez noted.</p><p>One example is the health-wealth gap. The mental stressors of maintaining a low socioeconomic status, especially in the face of extreme affluence, can have a physically degrading impact on health. <a href="https://www.scientificamerican.com/index.cfm/_api/render/file/?method=inline&fileID=123ECD96-EF81-46F6-983D2AE9A45FA354" target="_blank" rel="noopener noreferrer">Writing on this gap</a>, Robert Sapolsky, professor of biology and neurology at Stanford University, notes that socioeconomic stressors can increase blood pressure, reduce insulin response, increase chronic inflammation, and impair the prefrontal cortex and other brain functions through anxiety, depression, and cognitive load. </p><p>"Thus, from the macro level of entire body systems to the micro level of individual chromosomes, poverty finds a way to produce wear and tear," Sapolsky writes. "It is outrageous that if children are born into the wrong family, they will be predisposed toward poor health by the time they start to learn the alphabet."</p>Research on the economic and mental health fallout of COVID-19 is showing two things: That unemployment is hitting <a href="https://www.pewsocialtrends.org/2020/09/24/economic-fallout-from-covid-19-continues-to-hit-lower-income-americans-the-hardest/" target="_blank" rel="noopener noreferrer">low-income and young Americans</a> most during the pandemic, potentially widening the health-wealth gap further; and that the pandemic not only exacerbates mental health stressors, but is doing so at clinically relevant levels. As <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7413844/" target="_blank" rel="noopener noreferrer">the authors of one review</a> wrote, the pandemic's effects on mental health is itself an international public health priority.
Working to close the health gap<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDc5MDk1MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxNTYyMzQzMn0.KSFpXH7yHYrfVPtfgcxZqAHHYzCnC2bFxwSrJqBbH4I/img.jpg?width=980" id="b40e2" class="rm-shortcode" data-rm-shortcode-id="1b9035370ab7b02a0dc00758e494412b" data-rm-shortcode-name="rebelmouse-image" />
Northwell Health coronavirus testing center at Greater Springfield Community Church.
Credit: Northwell Health<p>Novel coronavirus may spread and infect indiscriminately, but pre-existing conditions, environmental stressors, and a lack of access to care and resources increase the risk of infection. These social determinants make the pandemic more dangerous, and erode communities' and families' abilities to heal from health crises that pre-date the pandemic.</p><p>How do we eliminate these divides? Dr. Salas-Lopez says the first step is recognition. "We have to open our eyes to see the suffering around us," she said. "Northwell has not shied away from that."</p><p>"We are steadfast in improving health outcomes for our vulnerable and underrepresented communities that have suffered because of the prevalence of chronic disease, a problem that led to the disproportionately higher death rate among African-Americans and Latinos during the COVID-19 pandemic," said Michael Dowling, Northwell's president and CEO. "We are committed to using every tool at our disposal—as a provider of health care, employer, purchaser and investor—to combat disparities and ensure the <a href="https://www.northwell.edu/education-and-resources/community-engagement/center-for-equity-of-care" target="_blank" rel="noopener noreferrer">equity of care</a> that everyone deserves." </p><p>With the need recognized, Dr. Salas-Lopez calls for health care systems to travel upstream and be proactive in those hard-hit communities. This requires health care systems to play a strong role, but not a unilateral one. They must build <a href="https://www.northwell.edu/news/insights/faith-based-leaders-are-the-key-to-improving-community-health" target="_blank" rel="noopener noreferrer">partnerships with leaders in those communities</a> and utilize those to ensure relationships last beyond the current crisis. </p><p>"We must meet with community leaders and talk to them to get their perspective on what they believe the community needs are and should be for the future. Together, we can co-create a plan to measurably improve [community] health and also to be ready for whatever comes next," she said.</p><p>Northwell has built relationships with local faith-based and community organizations in underserved communities of color. Those partnerships enabled Northwell to test more than 65,000 people across the metro New York region. The health system also offered education on coronavirus and precautions to curb its spread.</p><p>These initiatives began the process of building trust—trust that Northwell has counted on to return to these communities to administer flu vaccines to prepare for what experts fear may be a difficult flu season.</p><p>While Northwell has begun building bridges across the divides of the New York area, much will still need to be done to cure U.S. health care overall. There is hope that the COVID pandemic will awaken us to the deep disparities in the US.</p><p>"COVID has changed our world. We have to seize this opportunity, this pandemic, this crisis to do better," Dr. Salas-Lopez said. "Provide better care. Provide better health. Be better partners. Be better community citizens. And treat each other with respect and dignity.</p><p>"We need to find ways to unify this country because we're all human beings. We're all created equal, and we believe that health is one of those important rights."</p>
What’s Eminem doing in Missouri? Kanye West in Georgia? And Wiz Khalifa in, of all places, North Dakota?
This is a mysterious map. Obviously about music, or more precisely musicians. But what’s Eminem doing in Missouri? Kanye West in Georgia? And Wiz Khalifa in, of all places, North Dakota? None of these musicians are from those states! Everyone knows that! Is this map that stupid, or just looking for a fight? Let’s pause a moment and consider our attention spans, shrinking faster than polar ice caps.
MRI scans show that hunger and loneliness cause cravings in the same area, which suggests socialization is a need.
- A new study demonstrates that our brains crave social interaction with the same areas used to crave food.
- Hungry test subjects also reported a lack of desire to socialize, proving the existence of "hanger."
- Other studies have suggested that failure to socialize can lead to stress eating in rodents.
People sometimes crave socialization, literally.<p> Forty participants underwent 10 hours of either social isolation or fasting before being placed in an MRI machine. Those who fasted had their brains imaged while viewing pictures of food; those emerging from isolation viewed photos of socializing people. <strong><br> <br> </strong>The areas of the brain related to hunger pains, reward, and movements, the substantia nigra pars compacta and ventral tegmental area (SN/VTA), are also associated with cravings for food or addictive substances. When those who fasted viewed images of food, these regions of their brains lit up. Most interestingly, the same brain regions lit up when those who had been isolated for 10 hours saw pictures of other people socializing. <br> <br> Test subjects also filled out questionnaires during and after the fasting and isolation periods. Not only did this confirm that people felt cravings for what they had missed, but that the effect was similar in both cases. </p><p>They also showed that very hungry people were less responsive to images of socializing, suggesting that "hanger," the state of being irritable as a result of hunger, is a demonstrable <a href="https://www.insider.com/loneliness-and-hunger-have-similar-effects-on-the-brain-study-2020-11" target="_blank" rel="noopener noreferrer">state</a>. </p>
How can I use this information? I’m asking for a friend.<p> The obvious takeaway is that it is perfectly normal to feel a need for interaction with others after an extended bout of isolation. Our brains treat some form of interaction as a basic need that must be met. While not shown as clearly in humans, not getting these needs often drives mice to <a href="https://pubmed.ncbi.nlm.nih.gov/29334694/" target="_blank" rel="noopener noreferrer">stress ea</a><a href="https://pubmed.ncbi.nlm.nih.gov/29334694/" target="_blank" rel="noopener noreferrer">t</a>, a finding that makes a great deal of sense in light of these new findings. <br> </p><p>Exactly how we can meet the need for socialization outside of just meeting up with people (a tricky proposition at the time of writing) remains up for debate. Anybody who has tried a Zoom party during the pandemic can attest to it just not being as nice as seeing friends in person. <br> <br> The study's authors are aware of this issue and note that:<br> <br> "A vital question is how much, and what kinds of, positive social interaction is sufficient to fulfill our social needs and thus eliminate the neural craving response. Technological advances offer incessant opportunities to be virtually connected with others, despite physical separations. Yet, some have argued that using social media only exacerbates subjective feelings of isolation.<sup>"</sup><br> </p><p>Unfortunately, the study cannot offer us an answer to this question just yet. </p>
Like always, there are limitations to this study.<iframe width="730" height="430" src="https://www.youtube.com/embed/sgxMsgDWnAU" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe><p> This study involved 40 participants. While its essential finding is likely to be generally applicable, exactly how applicable it is to the broader population cannot be known with certainty from such a small group. The participants were also healthy, well-connected young adults who might react to various problems differently than other demographic groups. </p><p>Their tendency to do so while being the focus of endless studies on psychology is a well-recorded problem. <br> <br> Likewise, the fact that the participants knew they would only be isolated for 10 hours may have impacted how they reacted to the isolation—it is often easier to endure something when you know precisely when it will end. </p><p>Getting around that in future experiments may prove impossible. From an ethical standpoint, it would be difficult to structure an experiment on humans predicated on the idea that they will be kept isolated from all social interaction indefinitely. <br> <br> Lastly, while all of the participants were quite hungry after 10 hours, there were enough variations in how lonely people felt after isolation to suggest a more significant variance in need for socialization than in demand for food. While this seems obvious, we all know both introverts and extroverts; it does make it more challenging to determine how much social interaction counts as a "need" that the brain craves just as it craves food. </p><p>As usual, more research is needed.</p><p> The idea that humans are social animals existed long before modern neuroscience was possible. Now, we can see exactly what happens in the brain when we can't socialize. While the final word on the subject is still to be said, it might be time to give a friend a call. </p>
Researchers document the first example of evolutionary changes in a plant in response to humans.
- A plant coveted in China for its medicinal properties has developed camouflage that makes it less likely to be spotted and pulled up from the ground.
- In areas where the plant isn't often picked, it's bright green. In harvested areas, it's now a gray that blends into its rocky surroundings.
- Herbalists in China have been picking the Fritillaria dealvayi plant for 2,000 years.
Fritillaria dealvayi<p>The plant is <em> </em><a href="http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200027633" target="_blank"><em>Fritillaria dealvayi</em></a><em>,</em> and its bulbs are harvested by Chinese herbalists, who grind it into a powder that treats coughs. The cough powder sells for the equivalent of $480 per kilogram, with a kilogram requiring the grinding up of about 3,500 bulbs. The plant is found in the loose rock fields lining the slopes of the Himalayan and Hengduan mountains in southwestern China.</p><p>As a perennial that produces just a single flower each year after its fifth season, it seems <em>Fritillaria</em> used to be easier to find. In some places its presence is betrayed by bright green leaves that stand out against the rocks among which which it grows. In other places, however, its leaves and stems are gray and blend in with the rocks. What's fascinating is that the bright green leaves are visible in areas in which Fritillaria is relatively undisturbed by humans while the gray leaves are (just barely) visible in heavily harvested areas. Same plant, two different appearances.</p><div id="19cbf" class="rm-shortcode" data-rm-shortcode-id="c68d3086f5411ffd951edaad1cb811b9"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1329832938985435138" data-partner="rebelmouse"><div style="margin:1em 0">2/2: The picture on the left shows a Fritillaria delavayi in populations with high harvest pressure, and the one on… https://t.co/oriBNZGcsV</div> — University of Exeter News (@University of Exeter News)<a href="https://twitter.com/UniofExeterNews/statuses/1329832938985435138">1605891854.0</a></blockquote></div>
How we know we're the cause<p>There are other camouflaging plants, but the manner in which <em>Fritillaria</em> has developed this trait strongly suggests that it's a defensive response to being picked. "Many plants seem to use camouflage to hide from herbivores that may eat them — but here we see camouflage evolving in response to human collectors."</p><p>"Like other camouflaged plants we have studied," Niu says, " we thought the evolution of camouflage of this fritillary had been driven by herbivores, but we didn't find such animals." His close examination of Fritillaria leaves revealed no bite marks or other signs of non-human predation. "Then we realized humans could be the reason."</p><p>In any event, says Professor Hang Sun the Kunming Institute, "Commercial harvesting is a much stronger selection pressure than many pressures in nature."</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDgyNzM0My9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYzMDc3NDQwMn0.lXwsG0ShcnMcVLl06APdEeEOY5_WOs4UfN8oVCKsgtc/img.png?width=980" id="ccc8e" class="rm-shortcode" data-rm-shortcode-id="907e152dd5ad0429aa6350c53f5a85aa" data-rm-shortcode-name="rebelmouse-image" alt="herb shop" />
Credit: maron/Adobe Stock