ReportWire

Tag: recent research

  • ‘Gut Health’ Has a Fatal Flaw

    ‘Gut Health’ Has a Fatal Flaw

    [ad_1]

    In my childhood home, an often-repeated phrase was “All disease begins in the gut.” My dad, a health nut, used this mantra to justify his insistence that our family eat rice-heavy meals, at the exact same time every day, to promote regularity and thus overall health. I would roll my eyes, dubious that his enthusiasm for this practice was anything more than fussiness.

    Now, to my chagrin, his obsession has become mainstream. Social-media testimonials claim that improving your “gut health” not only helps with stomach issues such as bloating and pain but also leads to benefits beyond the gastrointestinal system (easing problems including, but not limited to, itching, puffy face, slow-growing hair, low energy, acne, weight gain, and anxiety). You can now find a staggering range of products claiming to support digestive health: Joining traditionally gut-friendly fermented foods such as yogurt and sauerkraut are “probiotic” or “prebiotic” teas, cookies, gummies, supplements, powders, and even sodas.

    The reality is less straightforward. Maintaining the health of the gastrointestinal tract, like the health of any body part, is always a good idea. But expecting certain foods and products to overhaul gut health is unrealistic, as is believing that they will guarantee greater overall well-being. Those claims are “a little bit premature,” Karen Corbin, an investigator at the Translational Research Institute of Metabolism and Diabetes, told me. Obsessing over it just isn’t worth the trouble, and can even do more harm than good. “Gut health” cookies, after all, are still cookies.

    In my dad’s defense, your gut does matter for your health. A massive microbial civilization lives mostly along the large intestine, helping the body get the most out of food. Broadly, a healthy gut is one where the different segments of this population—numerous species of bacteria, fungi, and viruses—live in harmony. An unhealthy one implies a disturbance of the peace: One group may grow too powerful, or an invading microbe may throw things off-balance, leading to problems including gastroenteritis and a compromised immune system.

    Diet in particular has a profound impact on the gut—and how it subsequently makes you feel. “Food can have effects on the microbiome, which can then secondarily affect the host,” Purna Kashyap, a gastroenterologist at the Mayo Clinic, told me. The effects of food on a person and their microbes, he added, are generally congruent; fast food, for example, is “bad for both of us.” Neglect to feed your microbiome and the balance of microbes could tip into disarray, resulting in an imbalanced gut and corresponding bloating, stomach pain, and problems with bowel movements.

    Fermented foods such as yogurt and kimchi, long considered good for digestive health, are known as “probiotics” because they contain live bacteria that take up residence in your gut. Other foods are considered “prebiotic” because they feed the microbes already in your gut—mostly fiber, because it isn’t digested in the stomach. Getting more fiber improves regularity and supports a more normal GI system, Corbin said.

    But the fundamental problem with the gut-health obsession is that “there’s no clear definition of a healthy gut microbiome,” Corbin said. The makeup and balance of people’s microbiomes vary based on numerous factors, including genes, diet, environment, and even pets. This means that a treatment that works to rebalance one gut might not work for another. It also means that a product promoting a healthy gut doesn’t mean anything concrete. The idea that achieving gut health, however it’s defined, can solve stomach-related issues is misguided; many diseases can cause abdominal distress.

    Less certain is how much gut health is responsible for benefits beyond the gastrointestinal tract. No doubt the microbiome is connected to other parts of the body; recent research has suggested that it has a role in weight gain, depression, and even cancer, supporting the idea that having a healthy gut could lead to other benefits. But the mechanisms underpinning them are largely unknown. Which microbes are involved? What are they doing? There are “a lot of tall claims based on animal studies that the microbiome influences diabetes or obesity or whatever,” and the translatability of those studies to humans is “really unlikely,” Daniel Freedberg, a gastroenterologist at Columbia University, told me. Until scientists can show definitively that microbe X leads to outcome Y, Corbin said, any relationships between the gut and overall health are “just correlations.”

    None of this is to say that paying more attention to your digestive health is a bad idea. Especially for people diagnosed with gastrointestinal problems like IBS or Crohn’s disease, it can be essential. For everyone else, pursuing a healthy gut with food and supplements can be a nonspecific process with poorly defined goals. The food industry has capitalized on interest in probiotics and prebiotics—as well as lesser-known postbiotics and synbiotics—making products such as “insanely probiotic” yogurt, probiotic-fortified chocolate and spaghetti, and prebiotic sodas. Particularly with probiotics, the specifics are lacking. Which bacteria, and how many of them, actually make it past the stomach into the colon isn’t well understood. “A lot of probiotics are unlikely to contain viable bacteria, and probably very few of them are really making it through to the colon,” Freedberg said.

    Prebiotics are generally more important, although the source matters. Prebiotic fiber is “one of the most important things that determines what bacteria are there,” Freedberg told me, but getting small amounts from fiber-fortified products isn’t going to make a huge difference. The soda brands Poppi and Olipop largely contain inulin, a type of fiber that’s common in food manufacturing for its slightly sweet taste, Freedberg explained, though it probably doesn’t contain a lot, otherwise it would become “sludgy.” Olipop contains about nine grams of fiber per can, roughly the same amount as one cup of cooked lima beans.

    Of course, any product that is inherently unhealthy won’t magically become good for you the moment fiber or live bacteria are added to it. With desserts and salty snacks, no amount of fiber “is going to overcome the issue” that they are full of sugar or salt, Corbin said. Concerns about medium aside, though, gut-health products elicited a shrug from her: Buying foods containing additional prebiotic fiber is a “reasonable approach,” so long as they’re healthy to begin with. If probiotics make a patient feel “fantastic,” Freedberg said, “I’m not going to rock the boat.” Prebiotic and probiotic products may help to a degree, but don’t expect them to overhaul an unhealthy gut one soda at a time. All of the experts I spoke with said that people concerned about their gut health should eat a lot of fruits, vegetables, whole grains, and legumes, and cut out junk that won’t feed their microbiome. In other words, a basic healthy diet is more than enough to achieve good gut health.

    My dad’s gut-health mantra was apparently borrowed from Hippocrates, suggesting that people have been obsessing over the digestive system for thousands of years with the belief that it is the key to overall health. The draw of this idea is its simplicity: Proposing that the body’s many ills can be collapsed into a single mega-ailment makes treatment seem refreshingly uncomplicated compared with the medical interventions needed to address individual problems. That the proposed treatments are easy and self-administrable—sipping fibrous soda, popping bacteria-packed pills—adds to the appeal.

    But perhaps what is most compelling about the idea is that there is some truth to it. Lately, research on the microbiome has seen some promising advances. A large study published in 2022 showed significantly elevated levels of certain bacteria in people with depressive symptoms. Another study, co-authored by Corbin in 2023, was one of the first to show, in a human clinical trial, that a high-fiber diet shifts the microbiome in a way that could promote weight loss. This moment is especially confusing because we are finally beginning to understand the gut’s connections to the rest of the body, and how eating certain foods can soothe it. Much more is known about the gut than in the days of Hippocrates, but still far less than the gut influencers on social media would have you believe.

    [ad_2]

    Yasmin Tayag

    Source link

  • The Pregnancy Risk That Doctors Won’t Mention

    The Pregnancy Risk That Doctors Won’t Mention

    [ad_1]

    The nonexhaustive list of things women are told to avoid while pregnant includes cat litter, alfalfa sprouts, deli meat, runny egg yolks, pet hamsters, sushi, herbal teas, gardening, brie cheeses, aspirin, meat with even a hint of pink, hot tubs. The chance that any of these will harm the baby is small, but why risk it?

    Yet few doctors in the U.S. tell pregnant women about the risk of catching a ubiquitous virus called cytomegalovirus, or CMV. The name might be obscure, but CMV is the leading infectious cause of birth defects in America—far ahead of toxoplasmosis from cat litter or microbes from hamsters. Bafflingly, the majority of babies infected in the womb are unaffected, but an estimated 400 born with CMV die every year. Thousands more end up with hearing and vision loss, epilepsy, developmental delays, or microcephaly, in which the head and brain are unusually small. Exactly why the virus so dramatically affects some babies but not others is unknown. There is no cure and no vaccine.

    Amanda Devereaux’s younger child, Pippa, was born with CMV, which caused damage to her brain. Pippa is prone to seizures. She could not walk until she was 2 and a half, and she is nonverbal at age 7. “I was just flabbergasted that no one told me about CMV,” says Devereaux, who is now the program director for the National CMV Foundation, which raises awareness of the virus. The nonprofit was founded by parents of children with congenital CMV. “Every single one of them says, ‘Why didn’t I hear about this?’” Devereaux told me.

    One reason that doctors have hesitated to spread the word is that the most obvious way to avoid this virus is to avoid infected toddlers. Symptoms from CMV are usually mild to nonexistent in healthy adults and children. Toddlers, who frequently pick up CMV at day care, can continue shedding the virus in their bodily fluids for months and even years while totally healthy. “I’ve encountered a classroom of 2-year-olds where every single child was shedding CMV,” Robert Pass, a retired pediatrician and longtime CMV researcher at the University of Alabama, told me when we spoke in 2021. (He recently died, at age 81.)

    This creates a common scenario for congenital CMV: A toddler in day care brings CMV home and infects Mom, who is pregnant with a younger sibling. One recent study found that congenital CMV is nearly twice as common in second-born children than in firstborns. Devereaux’s toddler son was in day care when she was pregnant. “I was sharing food with him because he would not finish his breakfast,” she told me. She had no idea that his half-eaten muffin could end up harming her unborn daughter. In hindsight, she says, “I wish I had spent less time worrying about not eating deli meat and more time focused on, Hey I’ve got this toddler at day care. I’m at risk for CMV.”

    CMV is such a tricky virus because few things about it are absolute. A mother cannot avoid her toddler categorically. Most pregnant women infected with CMV do not pass it to their babies. Most infected babies end up just fine. Doctors warn patients against many risks in pregnancy—see the list above—but in this case thousands of parents every year are blindsided by a very common virus. No one has a perfect answer for how to stop it.

    Day cares have been known as hot spots for CMV since at least the 1980s, when Pass, in Alabama, and other researchers in Virginia first began tracking congenital cases back to child-care centers. The virus is rampant in day cares for the same reason that other viruses are rampant in day cares: Young children are born with no immunity, and they aren’t very diligent about avoiding one another’s saliva, urine, snot, and tears, all of which harbor CMV. Of mothers with infected toddlers in day care, a third who have never had the virus catch it within a year. And getting CMV for the first time while pregnant is the riskiest scenario; these so-called primary infections are most likely to result in serious complications for the fetus. But recent research has found that reinfections and reactivations of the virus can lead to congenital CMV too. (CMV remains inside the body forever after the first infection, much like chickenpox, which is caused by a related virus.)

    So eliminating the risk of congenital CMV entirely is impossible. But some CMV experts advocate giving women a short list of actions to reduce their risk during the nine months of pregnancy: Avoid sharing food or utensils with toddlers in day care; kiss them on the top of the head instead of on the mouth; wash your hands frequently, especially after diaper changes; and clean surfaces that come in contact with saliva or urine. A study in Italy found that pregnant women who were taught these measures cut their risk of catching CMV by sixfold. A study in France found that it lowered risk too.

    In the U.S., patients are unlikely to hear this advice from their obstetricians, though. The American College of Obstetricians and Gynecologists doesn’t recommend telling patients about ways to reduce CMV risk. According to ACOG, the evidence that behavioral changes can make a difference—from just a handful of studies—is not strong enough, and the organization sees downsides to the approach. Advice such as not kissing babies and toddlers could harm “a mother’s ability to bond with her children,” and these hygiene recommendations could “falsely reassure patients” about their risk of CMV, Christopher Zahn, ACOG’s interim CEO, said in a statement to The Atlantic.

    The CMV community disagrees. “I think they’re being a bit paternalistic,” says Gail Demmler-Harrison, a pediatric-infectious-diseases doctor at Texas Children’s Hospital. A group of international CMV experts, including Demmler-Harrison, endorsed patient education in a set of consensus recommendations in 2017. Devereaux, with the CMV Foundation, frames it as a matter of choice. It shouldn’t be “somebody else is saying, ‘You can’t handle this information; I’m not going to share that with you,” she told me. Without knowing about CMV, women can’t decide what kind of risk they’re comfortable with or what kind of hygiene changes are too burdensome. “It’s your choice whether you make them or not,” she says. “Having that choice is important.”

    More data on how well these behavioral changes work might be coming soon: Karen Fowler, an epidemiologist at the University of Alabama at Birmingham, is enrolling hundreds of pregnant women in a clinical trial. Only 8 percent of participants had heard of CMV before joining the study, she says. Patients get a short information session about CMV and then 12 weeks of text-message reminders. Importantly, she says, “we’re keeping our message very simple”: Reduce saliva sharing: no eating leftover food, no sharing utensils, and no cleaning a pacifier in your mouth. This simple rule cuts off the most probable routes of transmission. Sure, CMV is also shed in urine, tears, and other bodily fluids—but mothers aren’t routinely putting any of those in their mouth.

    Prevention of CMV ends up the focus of so much attention because once a fetus is infected, the treatment options are not particularly good. The best antiviral against CMV is not considered safe to use during pregnancy, and another antiviral, although safer, is not that potent. After infected babies are born, antiviral therapy can help preserve hearing in those with other moderate to severe symptoms from CMV, but it can’t reverse damage in the brain. And it’s unclear how much antivirals help those with only mild symptoms. When does benefit outweigh risk? “There’s a big gray area,” says Laura Gibson, a pediatric-infectious-diseases doctor at the University of Massachusetts Chan Medical School. For these reasons, policies of whether to screen all newborns vary state to state, even hospital to hospital. Knowledge can be power—but with a virus as confusing as CMV, knowledge of an infection doesn’t always point to an obvious best choice.

    In an ideal world, all of this could be made obsolete with a CMV vaccine. But such a vaccine has proved elusive despite a lot of interest. In the U.S., the Institute of Medicine deemed a CMV vaccine the highest priority around the turn of the millennium, and about two dozen vaccine candidates have been or are being studied. All of the completed clinical trials, though, have failed. “The immunity may look robust in the first month or year, but then it wanes,” Demmler-Harrison says. And even vaccines that elicit some immune response are not necessarily able to elicit one strong enough to protect against CMV infection entirely.

    CMV is such a challenging virus to vaccinate against because it knows our immune system’s tricks. “It’s evolved with humans for millions of years,” Gibson says. “It knows how to get around and live with our immune system.” Our immune system is never able to eliminate the virus, which emerges occasionally from our cells to replicate and try to find another host. And so a vaccine that completely protects against CMV would need to prompt our immune system to do something it cannot naturally do. It would need to be better than our immune system. “As time goes on, I think fewer and fewer people are thinking that might work,” Gibson says. But a vaccine doesn’t have to protect against all infections to be useful. Because first infections are the riskiest for fetuses, being vaccinated could still reduce risk of congenital CMV.

    Whom to vaccinate is another complicated question to answer for CMV. We could vaccinate all toddlers, as we do against rubella, which is also most dangerous when passed from mother to fetus. This has the potential advantage of promoting widespread immunity that tamps down circulation of CMV, period. But the virus doesn’t actually harm toddlers much, and immunity could wane by the time they grow up to childbearing age. Or we could vaccinate teenagers, as we do against meningococcal disease, but teens are more likely to miss vaccines and again, immunity could wane too soon. So what about all pregnant women? By the time someone shows up at the doctor pregnant, it’s probably too late to protect during CMV’s highest risk period, in the first trimester. A better understanding of CMV immunity and spread could help scientists decide on the best strategy. Gibson is conducting a study (funded by Moderna, which is testing a CMV-vaccine candidate) on how the virus spreads and what kinds of immune responses are correlated with shedding.

    Until a vaccine is developed—should it happen at all—the only way to prevent CMV infection is the very old-tech method of avoiding bodily fluids. It’s imperfect. Its exact effectiveness is hard to quantify. Some people might not find it worthwhile, given the small absolute risk of CMV in any single pregnancy. There are, after all, already so many things to worry about when expecting a baby. Yet another one? Or, you might think of it, what’s one more?

    [ad_2]

    Sarah Zhang

    Source link

  • Quit Your Bucket List

    Quit Your Bucket List

    [ad_1]

    Years ago, just after I finished my psychiatry residency, a beloved supervisor called to say she had some bad news. At a routine checkup, she had glanced at her chest X-ray up on the viewing box while waiting for her doctor to come into the room. She was a trauma surgeon before becoming a psychiatrist and had spent years reading chest X-rays, so she knew that the coin-size lesion she saw in her lung was almost certainly cancer, given her long history of smoking.

    We had dinner soon after. She was still more than two years away from the end of her life and felt physically fine—vital, even. That’s why I was so surprised when she said she had no desire to spend whatever time she had left on exotic travel or other new adventures. She wanted her husband, her friends, her family, dinner parties, and the great outdoors. “Just more Long Island sunsets. I don’t need Bali,” she told me.

    At the end of life, you might expect people to feel regret for all the things they wanted to do and never made time for. But I have yet to know a patient or friend who, facing the blunt fact of their own mortality, had anything close to a bucket list. This squares with some recent research that shows that people tend to prefer familiar experiences more when they are reminded that their days are limited. The people I know even regretted the novelty they’d chased along the way, whether it was recreational-drug use or dating exciting people who they knew weren’t relationship material.

    Deathbed pronouncements can have limited applications for the rest of life, but this pattern suggests that novelty is perhaps overrated. Chasing the high of new sensations simply isn’t appealing for many people, and can sometimes even be bad for our health. I suspect that’s because, too often, the pursuit of novelty requires sacrificing the things we already know we love.

    It’s a common misconception that people who don’t have a taste for the newest, sexiest experience are dull, incurious, and unimaginative. A 2002 study found that people will switch away from their favorite, habitual choices when they know others are watching in order to avoid being judged as narrow-minded. And yet, Warren Buffett notoriously eats breakfast at the same fast-food restaurant every day and sticks to a strict work schedule. Taylor Swift’s music can be redundant and predictable. Barack Obama is famous for his strict morning exercise regime and daily reading time.

    Even when they’re not facing death, many people just don’t seem to like novelty that much. In 2017, a poll by a British soup company found that 77 percent of U.K. workers had consumed the exact same lunch every day for nine months and that one in six people had done so for at least two years. You might think it’s just a matter of convenience or economic exigency (the study didn’t say), but I’m not so sure; wealthy people I know partake in similar behavior, even if they do it at a fancy restaurant. Consider, too, that when people lose a pet, many run out and get a replacement of the same breed with a similar temperament. They repeatedly date people with the same quirks and problems. They return to a favorite vacation spot. They listen to the same musical artists and styles time and again.

    Read: The people who eat the same meal every day

    Research shows that humans have an intrinsic preference for things and people they are familiar with, something called the mere exposure effect. Several studies have shown that people who listen to unfamiliar songs repeatedly grow fonder of the songs they hear most  by the end of the experiment, even if they did not initially like them very much. You don’t even have to be aware that you’re growing used to something for the effect to work.

    This tendency toward repetition may seem natural, even lazy, but it runs counter to much of our history. We, along with other animals, evolved to be exquisitely sensitive to novel experiences. Way back in the Paleolithic era, there was a clear survival advantage to being attuned to new situations, which could lead someone to a potential mate or a piece of mastodon, or reveal a deadly threat. Nowadays, though, with every conceivable reward—food, sex, drugs, emotional validation, you name it—either a click, tap, or ChatGPT query away, conventional novelty-seeking has lost much of its adaptive advantage.

    As Arthur Brooks has written in The Atlantic, novelty can be fun and exciting. New and unexpected experiences activate the brain’s reward pathway more powerfully than familiar ones, leading to greater dopamine release and a more intense sense of pleasure. But on its own, excitement won’t bring about enduring happiness. Human beings habituate rapidly to what is new. To achieve a lifetime of stimulation, you would have to embark on an endless search for the unfamiliar, which would inevitably lead to disappointment. Worse, the unfettered pursuit of novelty can lead to harm through excessive thrill-seeking—including antisocial behavior such as reckless driving—particularly when the novelty seeker has poor impulse control and a disregard for others.

    Read: Don’t approach life like a picky eater

    There’s a better way. Research shows that when novelty-seeking is paired with persistence, people are far more likely to be happy, probably because they are able to achieve something meaningful. You might, for example, take a variety of courses in college or try different summer internships if you’re not yet sure what interests you. When one really clicks, you should explore it in depth; it might even become a lifelong passion. This principle relates to less consequential pleasures, too: If you’re checking out a new neighborhood joint, consider ordering different things during your first few visits, then picking your favorite and sticking with it.

    Novelty-seeking is most valuable when you use it as a tool to discover the things and people you love—and once you find them, go deep and long with those experiences and relationships. The siren call that tells you there might be a new and better version of what you already have is likely an illusion, driven by your brain’s relentless reward pathway. When in doubt, pick a beloved activity over an unfamiliar one.

    This golden rule of novelty may help explain why some people at the end of their life regret having spent so much time exploring new things, even if they once brought fleeting pleasure. Age, too, might partly explain this feeling, because older people tend to be less open to new experiences. But that’s probably not the whole story. My colleagues who treat children and adolescents have mentioned that, in the face of life-threatening diagnoses, even young people prefer the familiar. They do so not only because the familiar is known and safe, but because it is more meaningful to them. After all, things become familiar to us because we choose them repeatedly—and we do that because they are deeply rewarding.

    Read: Make a to-don’t list

    Imagine, just for a moment, that your death is near. What might you miss out on if you put your bucket list on hold? Sure, you won’t make it to Bali or Antarctica. But maybe instead you could fit in one last baseball game with your kids, one last swim in the ocean, one last movie with your beloved, one last Long Island sunset. If you prioritize the activities and people you already love, you won’t reach the end of your life wishing you’d made more time for them.

    [ad_2]

    Richard A. Friedman

    Source link