Can Coffee Ease Depression, Obesity, Memory Loss? When Is It a Danger? | CLIP | Vital Signs

Okay Gary, ready to roll? Today's your favorite topic, coffee, and I got my own little heart study here to kick off the day. Brendan, it's America, so you need big one. Isn't this a little bit too much? This give you energy. You may recall an earlier video I did looking at coffee's link to living longer and expressing my deep love for the caffeine queen. Well, nothing's changed on that front. I still love coffee, but I've switched up my drinking patterns a lot since that time. I'll explain why as we get into the nuts and bolts of this deep dive into the benefits and risks of coffee consumption. On YouTube, videos are everywhere about coffee. Coffee is good for your coffee. It's New York, so you need to say coffee. Coffee. When in Rome. Videos are bound on YouTube with titles like, Why I'll Never Drink Coffee Again, or the Seven Remarkable Health Benefits of Coffee. So which is it? Is coffee the extender of life, or the hard binger of death? Well, the answer is kaleidoscopic, as are all the different factors we're going to look at today. From how caffeine intake correlates to heart health, brain health, and brain function, to how coffee rates as a drug of addiction, and the unique effect it may have on children's brains. So strap yourselves in for a deep dive into coffee's risks versus benefits. Welcome to Vital Signs, where we learn how to get healthy from all angles, from the biochemical and nutritional, to the things we do that nourish our minds and our souls. I'm Brendan Falun. And where better to start than the beginning? Before coffee made its grand Western world debut. Before caffeine, people used to drink more alcohol. That's because it was easier to get sick from drinking the water at the time. Even children would have hard cider for breakfast. Tea, chocolate, and coffee arrived in England in the 1650s. These new drinks benefited more than just the taste buds, reason being tea and coffee necessitate boiling, thus rendering water safer to drink, which in turn elevated public health at the time. What's more, downing a beverage that boosted rather than subdued mental function, as alcohol does, was linked to greater advancements in human thought at the time. It's even said that the Enlightenment and the Industrial Revolution were aided by the more sober, clearer thinking, and more functional society that these popular drinks ushered in. Coffee houses began popping up all over London as caffeine became widespread in Europe in the 17th century. The great writers and thinkers of the day gathered in such places to discuss literature, poetry, and science. The coffee break is a stirring example of how coffee aided productivity. Legend goes that a necktie company lost its weavers to the war effort during World War II. They hired older men, but these men weren't skilled at weaving, so they hired women. And the women did wonderfully, but only for a handful of hours before they got tired. So company execs put their heads together, what could be done to get more neckties made? The solution? A warm cup of coffee in the middle of the day. Henceforth known as the coffee break, and as legend has it, productivity increased immediately. And this leads us into the effect of drinking coffee, which actually varies across species. For instance, to get your morning buzz, you might hit your local 7-Eleven or your boutique corner cafe if you're putting on the Ritz. But in nature, insects can only rely on the fruits and leaves of coffee and tea plants to get their caffeine fix. And it isn't always a fairy tale ending. Insects can be paralyzed or even killed by the caffeine. You heard right. Caffeine is essentially an insecticide. These plants use caffeine to protect themselves from being eaten by insects. That said, the effect of this neurotoxin on humans is slightly different. When humans take caffeine, it stimulates the central nervous system, which gives us a buzz. It dispels drowsiness, enhances attention, raises alertness, and can make thinking more clear and agile. And the reason? It all comes back to how our bodies use energy. If you think back to the high school biology, you'll recall that the energy currents of our bodies is adenosine triphosphate, or ATP. It's used for muscle contraction, for transfer of nerve impulses, for chemical synthesis in the body. And when that ATP molecule is broken down, releasing energy, it also releases adenosine. This is where the coffee connection comes in, because adenosine, like caffeine, has a direct connection to how tired or awake we feel. While you're awake, adenosine slowly builds up in the brain. It binds to adenosine receptors, triggering chemical reactions that make you feel tired. The more adenosine in the brain, the more tired you feel. This is why you get more tired the longer you're awake. On the flip side, as you sleep, adenosine levels decline, leading you to hopefully feel ready for action when you wake up. Here's where caffeine enters the stage. Caffeine is incredibly similar to adenosine in structure. Caffeine works its way through your bloodstream and to your brain. Once in the brain, it binds with adenosine receptors. But because it's not adenosine, the tiredness effect isn't felt. If the caffeine is crowding out adenosine, then less adenosine is able to bind. And the proverbial sandman doesn't come with such urgency. Which is all well and good. You're feeling weary, but you've got a job to do. Why not crowd out some of that adenosine with caffeine? Well, we've all done that, and it may well seem to get us over the hump of the day. One thing it's important to keep in mind, though, is a good reason that we feel tired. Research suggests adenosine is there to protect the brain against energy depletion, to force sleep before the energy balance of the whole brain is affected. Earlier, I spoke to Dr. Daniel Amen, a psychiatrist who uses specialized imaging to show patients how different substances like marijuana, like caffeine, impact their brains, and thus, their mental health. This is what he said about caffeine cancelling out adenosine. The problem is, adenosine is still going up, but it blocks the effect of it, and you end up with a rebound the next day. And that's why people start their days with caffeine. Because what they're really doing is medicating sleep deprivation. And I would just argue, if you get rid of caffeine, your sleep's going to be better, your energy's going to be better. It's a short-term fix that continues to cause a long-term problem. And yet, as with so many things, there is a flip side to this. Due to caffeine's effects on certain adenosine receptors, like the A1 adenosine receptor, caffeine has long been proposed to treat memory disorders. You see, caffeine's cognitive effects, like alertness, are mostly due to its ability to affect A1 adenosine receptors in the hippocampus and cortex, which are brain areas mostly involved in cognition. One study used the drug scopolamine, also known as devil's breath, and which has a long history of criminal abuses. Researchers used scopolamine to induce memory loss in rats, and then they used an A1 adenosine receptor blocker, which is what caffeine is, to reverse the memory loss in the rats. With effects like these, it's no surprise that coffee's linked to a lower risk of getting Alzheimer's disease. A 2009 study analyzed 20 years of follow-up data on 1,400 participants. Those who drank three to five cups of coffee daily had a 65% lower risk of developing Alzheimer's disease, compared to non-coffee drinkers. In another study, mice were given caffeine in their drinking water from young adulthood into older age. These mice displayed protection against memory impairment. They also showed lower brain levels of the abnormal protein amyloid beta, or A-beta, which is believed to contribute to Alzheimer's disease. After only two months of caffeine therapy, the older, cognitively impaired mice exhibited memory restoration and lower brain A-beta levels. And if coffee has scope to help ward off dementia, it's not such a stretch to imagine it also has antidepressant properties. A study by the Harvard School of Public Health in 2011 analyzed data from 50,000 women. The study found that women who drank two to three cups of coffee per day had a 15% lower risk of developing depression, compared to non-coffee drinkers. Women who drank four cups had a 20% lower risk. Two years later, in another study, they showed drinking two to four cups of coffee per day was linked to a lower suicide rate than that found in the general population. Now, why would coffee potentially influence mental health? Again, it has to do with those receptors for adenosine, and one in particular called A2A, known to have interactions with receptors for dopamine, the feel-good hormone. Research shows mice injected with A2A adenosine receptor blockers were less sensitive to depressant challenges than mice who were not given the blockers. As such, it's thought that blocking A2A adenosine receptors, which is basically what caffeine does, it's thought that blocking these receptors could be a target for future antidepressant drugs. However, as you sit there sipping your skinny double frappuccino latte, basking in the glow of caffeine's potential memory-preserving and mood-enhancing effects, there is a concomitant dark side to caffeine's medicinal promise. And it also ties into interactions with the body's dopamine, aka feel-good system. I refer, of course, to caffeine's addiction and habit-forming potential. As it happens, cocaine also acts on the body's dopaminergic system. It's presumed that cocaine works by blocking dopamine uptake, thus prolonging how long dopamine remains in the extracellular space. It's suggested caffeine could have a similar, albeit less potent, effect. This is one reason why we might find caffeine addictive. Of course, we can't exactly equate caffeine with drugs of addiction like cocaine or heroin. However, how do you fare when you miss your morning caffeination? Extreme fatigue and headaches are common for those skipping their daily caffeine fix. And the reason? Well, these are your basic symptoms of withdrawal. And remember the chemical adenosine that we discussed earlier? The more adenosine you have in the brain, the more tired you feel. While caffeine can help block the effects of adenosine in the brain, with long-term use of caffeine, your brain responds by creating more adenosine receptors. This essentially builds up an immunity to caffeine. Over time, more caffeine is required to make you feel awake. This immunity creates a dependence for more and more coffee, causing withdrawals when you try to quit.