Fiber Is Good for You. Now Scientists May Know Why.

Fiber Is Good for You. Now Scientists May Know Why.

A diet of fiber-rich foods, such as fruits and vegetables, reduces the risk of developing diabetesheart disease and arthritis. Indeed, the evidence for fiber’s benefits extends beyond any particular ailment: Eating more fiber seems to lower people’s mortality rate, whatever the cause.

That’s why experts are always saying how good dietary fiber is for us. But while the benefits are clear, it’s not so clear why fiber is so great. “It’s an easy question to ask and a hard one to really answer,” said Fredrik Bäckhed, a biologist at the University of Gothenburg in Sweden.

He and other scientists are running experiments that are yielding some important new clues about fiber’s role in human health. Their research indicates that fiber doesn’t deliver many of its benefits directly to our bodies.

Instead, the fiber we eat feeds billions of bacteria in our guts. Keeping them happy means our intestines and immune systems remain in good working order.

In order to digest food, we need to bathe it in enzymes that break down its molecules. Those molecular fragments then pass through the gut wall and are absorbed in our intestines.

But our bodies make a limited range of enzymes, so that we cannot break down many of the tough compounds in plants. The term “dietary fiber” refers to those indigestible molecules.

But they are indigestible only to us. The gut is coated with a layer of mucus, atop which sits a carpet of hundreds of species of bacteria, part of the human microbiome. Some of these microbes carry the enzymes needed to break down various kinds of dietary fiber.

The ability of these bacteria to survive on fiber we can’t digest ourselves has led many experts to wonder if the microbes are somehow involved in the benefits of the fruits-and-vegetables diet. Two detailed studies published recently in the journal Cell Host and Microbe provide compelling evidence that the answer is yes.

In one experiment, Andrew T. Gewirtz of Georgia State University and his colleagues put mice on a low-fiber, high-fat diet. By examining fragments of bacterial DNA in the animals’ feces, the scientists were able to estimate the size of the gut bacterial population in each mouse.

On a low-fiber diet, they found, the population crashed, shrinking tenfold.

Dr. Bäckhed and his colleagues carried out a similar experiment, surveying the microbiome in mice as they were switched from fiber-rich food to a low-fiber diet. “It’s basically what you’d get at McDonald’s,” said Dr. Bäckhed said. “A lot of lard, a lot of sugar, and twenty percent protein.”

The scientists focused on the diversity of species that make up the mouse’s gut microbiome. Shifting the animals to a low-fiber diet had a dramatic effect, they found: Many common species became rare, and rare species became common.

Along with changes to the microbiome, both teams also observed rapid changes to the mice themselves. Their intestines got smaller, and its mucus layer thinner. As a result, bacteria wound up much closer to the intestinal wall, and that encroachment triggered an immune reaction.

After a few days on the low-fiber diet, mouse intestines developed chronic inflammation. After a few weeks, Dr. Gewirtz’s team observed that the mice began to change in other ways, putting on fat, for example, and developing higher blood sugar levels.

Dr. Bäckhed and his colleagues also fed another group of rodents the high-fat menu, along with a modest dose of a type of fiber called inulin. The mucus layer in their guts was healthier than in mice that didn’t get fiber, the scientists found, and intestinal bacteria were kept at a safer distance from their intestinal wall.

Dr. Gewirtz and his colleagues gave inulin to their mice as well, but at a much higher dose. The improvements were even more dramatic: Despite a high-fat diet, the mice had healthy populations of bacteria in their guts, their intestines were closer to normal, and they put on less weight.

Dr. Bäckhed and his colleagues ran one more interesting experiment: They spiked water given to mice on a high-fat diet with a species of fiber-feeding bacteria. The addition changed the mice for the better: Even on a high-fat diet, they produced more mucus in their guts, creating a healthy barrier to keep bacteria from the intestinal walls.

One way that fiber benefits health is by giving us, indirectly, another source of food, Dr. Gewirtz said. Once bacteria are done harvesting the energy in dietary fiber, they cast off the fragments as waste. That waste — in the form of short-chain fatty acids — is absorbed by intestinal cells, which use it as fuel.

But the gut’s microbes do more than just make energy. They also send messages.

Intestinal cells rely on chemical signals from the bacteria to work properly, Dr. Gewirtz said. The cells respond to the signals by multiplying and making a healthy supply of mucus. They also release bacteria-killing molecules.

By generating these responses, gut bacteria help maintain a peaceful coexistence with the immune system. They rest atop the gut’s mucus layer at a safe distance from the intestinal wall. Any bacteria that wind up too close get wiped out by antimicrobial poisons.

While some species of gut bacteria feed directly on dietary fiber, they probably support other species that feed on their waste. A number of species in this ecosystem — all of it built on fiber — may be talking to our guts.

Going on a low-fiber diet disturbs this peaceful relationship, the new studies suggest. The species that depend on dietary fiber starve, as do the other species that depend on them. Some species may switch to feeding on the host’s own mucus.

With less fuel, intestinal cells grow more slowly. And without a steady stream of chemical signals from bacteria, the cells slow their production of mucus and bacteria-killing poisons.

As a result, bacteria edge closer to the intestinal wall, and the immune system kicks into high gear.

“The gut is always precariously balanced between trying to contain these organisms and not to overreact,” said Eric C. Martens, a microbiologist at the University of Michigan who was not involved in the new studies. “It could be a tipping point between health and disease.”

Inflammation can help fight infections, but if it becomes chronic, it can harm our bodies. Among other things, chronic inflammation may interfere with how the body uses the calories in food, storing more of it as fat rather than burning it for energy.

Justin L. Sonnenburg, a biologist at Stanford University who was not involved in the new studies, said that a low-fiber diet can cause low-level inflammation not only in the gut, but throughout the body.

His research suggests that when bacteria break down dietary fiber down into short-chain fatty acids, some of them pass into the bloodstream and travel to other organs, where they act as signals to quiet down the immune system.

“You can modulate what’s happening in your lung based on what you’re feeding your microbiome in your gut,” Dr. Sonnenburg said.

Hannah D. Holscher, a nutrition scientist at the University of Illinois who was not involved in the new studies, said that the results on mice need to be put to the test in humans. But it’s much harder to run such studies on people.

In her own lab, Dr. Holscher acts as a round-the-clock personal chef. She and her colleagues provide volunteers with all their meals for two weeks. She can then give some of her volunteers an extra source of fiber — such as walnuts — and look for changes in both their microbiome and their levels of inflammation.

Dr. Holscher and other researchers hope that they will learn enough about how fiber influences the microbiome to use it as a way to treat disorders. Lowering inflammation with fiber may also help in the treatment of immune disorders such as inflammatory bowel disease.

Fiber may also help reverse obesity. Last month in the American Journal of Clinical Nutrition, Dr. Holscher and her colleagues reviewed a number of trials in which fiber was used to treat obesity. They found that fiber supplements helped obese people to lose about five pounds, on average.

But for those who want to stay healthy, simply adding one kind of fiber to a typical Western diet won’t be a panacea. Giving mice inulin in the new studies only partly restored them to health.

That’s probably because we depend on a number of different kinds of dietary fiber we get from plants. It’s possible that each type of fiber feeds a particular set of bacteria, which send their own important signals to our bodies.

“It points to the boring thing that we all know but no one does,” Dr. Bäckhed said. “If you eat more green veggies and less fries and sweets, you’ll probably be better off in the long term.”

This article was originally published in The New York Times. Read the original article.

Is There a Downside to Going Gluten-Free if You’re Healthy?

Is There a Downside to Going Gluten-Free if You’re Healthy?

Q. Is there a downside to following a gluten-free or grain-free diet for someone who is not highly sensitive to gluten? Are there any benefits?

A. A gluten-free or grain-free diet can pose risks and is not recommended for someone who is not highly sensitive to gluten. Such a diet is also unlikely to provide any benefits.

“There’s no reason for someone who feels well to start a gluten-free diet to promote wellness,” said Dr. Benjamin Lebwohl, director of clinical research at the Celiac Disease Center at Columbia University. “It is not an intrinsically wellness-promoting diet.”

One of the main problems in avoiding gluten-containing grains like wheat, rye or barley as well as other grains is that it can reduce the overall quality of someone’s diet. “The most common issue people run into when starting a gluten-free diet is fiber intake often plummets,” Dr. Lebwohl said. Fiber is important for overall digestive health, so inadequate intake can lead to constipation and other bowel problems; it may also make you not feel as full, which can lead to excess calorie intake and potential weight gain. While grains aren’t the only source of fiber available, they are a good one, and most Americans fail by a long shot to get the recommended intake of about 20 to 40 grams a day, depending on gender and age.

If following a gluten-free diet means eschewing whole grains, that can be especially problematic, because whole grains are associated with numerous health benefits, especially for heart health. As part of a healthy diet, high intake of whole grains has been associated with reduced risk of heart disease, some cancers, Type 2 diabetes, obesity and death from numerous causes, including infections and respiratory diseases.

“Gluten-free substitute foods tend to have more fat, more sugar and more salt than gluten-containing counterparts, in general,” Dr. Lebwohl added. Gluten provides elasticity in dough and helps thicken various processed foods, so it can also be found in products like energy bars and deli meats. To compensate for the loss of texture, Dr. Lebwohl said, “gluten-free substitutes are often less healthy.”

Starting a gluten-free diet can also “interfere with the ability to detect celiac disease,” said Dr. Lebwohl, because the two abnormalities picked up by the primary testing tools for celiac disease — a blood test, which looks for certain antibodies, and a biopsy, which looks for intestinal damage — can normalize after just a few weeks of eliminating gluten.

“One of the frustrating scenarios for both doctor and patient is when a patient has a number of symptoms, starts a gluten-free diet, feels a lot better — maybe 90 percent better — but we still don’t know if they have celiac or not,” he said. “If someone is experiencing symptoms that might be related to celiac disease, that person should get tested first, before starting a gluten-free diet.”

While much has been written in books and online sources about the purported benefits of avoiding gluten, such as weight loss, cognitive well-being and overall wellness, these claims are not supported by evidence. Though some patients with irritable bowel syndrome, or I.B.S., may see symptoms improve after cutting out gluten-containing foods, research suggests it’s likely to be a result of something other than gluten.

Only about 1 percent of Americans have true celiac disease, a serious autoimmune disorder, and should follow a strict gluten-free diet. Another 6 percent or so have non-celiac gluten sensitivity, a milder condition tied to digestive problems and other symptoms that does not result in a positive test for celiac disease; observing whether symptoms improve after a trial elimination of gluten is the main method of diagnosis.

For everyone elsefollowing a gluten-free diet is not advised. Still, a 2013 report by the NPD Group, a market research firm, found that as many as one in three Americans were trying to avoid gluten.

“The potential adverse health effects of gluten in those sensitive to it have reverberated in cyberspace, creating the impression that gluten is a bona fide toxin, harmful to all,” writes Dr. David L. Katz, director of the Yale-Griffin Prevention Research Center in his forthcoming book, “The Truth About Food.” “This is false; gluten is not ‘bad’ for those tolerant of it, any more than peanuts are ‘bad’ for people free of peanut allergy.”

“Avoiding whole grains because you’ve heard gluten is bad is like avoiding whole fruits because you’ve heard fructose is bad,” Dr. Katz said in an interview. A diet without gluten is most often associated with the inclusion of what he calls “ultra-processed, gluten-free junk foods” and the exclusion of highly nutritious whole grains. “Avoiding it systematically produces net harm both to diet and to health.”


This article was originally published in The New York Times. Read the original article.

Keto, gut health and fasting are all the rage. Are they worth all the hype?

Keto, gut health and fasting are all the rage. Are they worth all the hype?

As January nears its conclusion, how are you doing with your New Year’s health resolutions? How’s your willpower holding up on that keto diet? Are those probiotic supplements making your gut happy?

These new and shiny health trends have skyrocketed in popularity. Celebrities sing the praises of stunt diets and esoteric supplements. Intermittent fasting, it seems, has become big with the local tech bro scene.

Me, I’ve never been one for resolutions, especially the dietary kind, because, hey, I work in food. (I also don’t like other people telling me what I should and shouldn’t eat.)


That said, for a few weeks now, I’ve been following an anti-inflammatory diet. Currently I am avoiding booze, bread, pasta and processed sugar; basically, all of the tasty things that make life fun. The thing is, I’m actually feeling better. I’m not certain of the reason, but my joints seem to be aching less, I’m sleeping better and have more energy. Still, I miss doughnuts.

When it comes down to it, we all want to feel better, and what we put in our bodies (or don’t) is a big part of that. However, making heads or tails of these diet and health trends can be mind-boggling.

I recently spoke with Danica Cowan, M.S./R.D., a registered dietitian and nutritionist at UCSF’s Osher Center for Integrative Medicine, to learn more about these trends — what they are, what works and what is plain old marketing hooey.

The ketogenic diet

Probably the highest profile diet right now is the ketogenic diet, or keto for short. By consuming foods that are high in fat and minimizing carbohydrate intake, it’s designed to get the body to burn fats instead of carbs, and to reach a metabolic state known as ketosis.

However, there are two kinds of ketogenic diets, says Cowan: the one used to treat certain medical conditions, and the fad type used for weight loss.

The medical diet, which has been around for decades, was originally intended to treat pediatric epilepsy and can be pretty effective for that, Cowan says. There’s also a lot of emerging research about the ketogenic diet and its effect on lowering inflammation in the brain, as well as diabetes.

As for the fad diet, however, casual fad dieters are probably not in ketosis; instead, most people may simply be on a low-carb diet with extra fat.

In general, the ketogenic diet is not intended to be followed for a long period of time, says Cowan, and as such, researchers don’t fully know yet the long-term effects that the diet may have.

“The thing that makes me nervous about the keto diet is the unlimited permission to eat all the fats they want, including unhealthy fats,” says Cowan.

So, before you reach for that extra helping of bacon — which Cowan reminds us is not a health food — it’s important to work with an experienced dietitian or nutritionist who understands the keto diet, “because you’re basically changing the way your body functions.”

Intermittent fasting

Exactly what it sounds like, intermittent fasting is a catch-all term that can mean everything from going without food for a couple of days a month to simply lengthening the amount of time between finishing dinner and eating breakfast.

For those of us who love food and take pleasure in eating, the idea of fasting may seem extreme, but Cowan believes there are potential benefits in this approach.

Having more time between meals allows the body more time to rest and repair itself. The routine’s flexibility means that it can be relatively easy for people to incorporate it into their daily schedule. Even if you decide that intermittent fasting isn’t for you, Cowan does encourage people to stop eating about two to three hours before bed.

Gut health

Wander the aisle of your neighborhood market and you’ll spot all sorts of foods and drinks touting that they’re infused with probiotics and prebiotics. But what exactly are probiotics and prebiotics, and what do they do?

Probiotics are live bacteria that are ingested with the intention that they will take up residence in your intestines. Prebiotics are the food for the probiotics and can be found in high-fiber sources like fresh fruit, vegetables and whole grains. As a result of eating prebiotics, probiotics produce short-chain fatty acids, which have beneficial effects on the gastrointestinal system.

As for all those energy bars, cereals and other prepared foods that are marketed as being loaded with pre- and probiotics, Cowan recommends approaching those with a healthy dose of skepticism.

“Most food marketing is b.s.; some have science behind it; 95 percent of it is marketing,” says Cowan. “Adding something healthy to something unhealthy does not make it healthy.”

Generally speaking, Cowan recommends using refrigerated supplements over shelf-stable ones, and ideally, they should have at least 10 strains of different bacteria. To have an impact, they also have to be taken regularly.

Other sources that are great for promoting a more gut-friendly diet: fermented foods, especially yogurt (plain and unsweetened), kimchi, sauerkraut, lacto-fermented pickles and kefir. Kombucha, which contains a lot of yeasts, can be problematic for some people with gastrointestinal concerns. (It is, however, a good replacement for soda.)

What a lot of these diets have in common, says Cowan, is cutting out unhealthy foods. “At the end of the day, if you’re eating more whole, unprocessed foods and less processed junk, that’s going to benefit anyone,” she says.

Be mindful about eating habits, and prioritize what works for you. Above all, be kind to yourself, Cowan says. “People beat themselves up about what they eat or don’t eat, and that’s not healthy.”

This article was originally published in Wired. Read the original article.



QUOTE-UNQUOTE UNHEALTHY FOOD. That’s how Christy Harrison, one of a new group of rogue dieticians, describes Chicken McNuggets. I can’t get enough of how she, formerly a food purist and determined orthorexic, uses that quote-unquote locution on her podcast Food Psych, a deceptively sweet piece of heresy that takes aim at the pieties, sophistries, and perils of diet culture.

At its heart, Harrison’s podcast is an intensive project of pop deconstruction—and if liberation is your goal, it works. It’s ecstatic. It’s terrifying. But while an antidiet project can almost certainly make you happier, freer, and more productive than you are now, you may also be fatter. So there’s that.

A podcast about dieting that might lead to weight gain? Yes, I realize: no. But a friend pushed Food Psych on me, and now I never miss an episode. What once sounded to me like modish self-help has become an authentic philosophical endeavor, chronicled in academic papers, podcasts, books, and social media. At the same time, in seeming to put up for grabs the self-evident connections between food, weight, and health, it can smack of disquieting science denialism.

I’d argue it’s not, and I’m prepared to spell that out. In the past 15 years, public health journals have steadily documented the health risks posed by food restriction. Moreover, the antidiet project is above all a cultural one—a breaking of chains that makes a priority of sustained mental health over the illusion of bodily thinness.

The work of the antidiet crowd asks anyone touched by diet culture to entertain the possibility that body weight doesn’t, in itself, cause health issues. Some activists challenge dieters to exit the cult of food restriction by doing rad things like skipping the gym and eating salty, fatty, sugary fast food (including McNuggets)—whenever the spirit moves you. As rites of passage into freedom go, this one is pretty great and includes the jubilant breaking of a legitimate taboo. For chronic dieters like myself, it also demands a measure of courage. Because, let’s face it, in eating trans fats you’re not just preempting your chances of ever matching Balenciaga’s beauty ideal. You’re crossing the World Health Organization, which still maintains that fast and shelf-stable foods are unsafe at any dose.

To me, the most staggering scientific suggestion in the antidiet movement is that there might not be a causalrelationship in the familiar correlation between higher body weight and health issues. According to figures like Harrison, the one thing we can say for certain about people who get labeled “fat” is not that they have deposits of adipose tissue that interfere in observable ways with heart health and blood sugar. What we can say is that fat people in America, number one, experience weight stigma and, two, are always or often on diets.

How could these slippy-slidey phonemes about diet culture ever have had any moral sway over me?

Weight stigma can be brutal, dramatically affecting everything from work and travel to romance. At the same time—rather than sadistically goad people in bigger bodies into some mythical food regimen that turns them thin for good—it “poses serious risks to their psychological and physical health,” according to a 2010 paper in the American Journal of Public Health. The risks of weight stigma might even be greater than the risk of weight itself.

Then there are the dangers of dieting. According to studies in the American Journal of Physiology–­Endocrinology and Metabolism (2014) and Evolution, Medicine, and Public Health (2016), food restriction of almost any form—famine, elimination diets, wellness diets—routinely upsets hormonal regulation, potentially setting off serious mental and physical health problems and, paradoxically, weight gain.

Some of Food Psych’s experts identify as fat. Some must regularly check their “thin privilege.” But in keeping with the rigor of their critique, “thin” and “fat” are recognized as cultural conceits without objective correlates. So diet critics decline to use numbers like pounds, calories, or dress sizes to identify bodies. For those who have long attended compulsively to body size and its relation to food purity, categories, and quantity, numbers seem to shimmer with moral significance—and the ever-present possibility of moral failure on the scale.

A central aim of the antidiet project is to divest the language of bodies and food of all its moral content. That’s why the critics focus so hard on language. Harrison just won’t let the words “healthy” or “unhealthy” (or for that matter “wellness,” “overweight,” or “clean eating”) slip the bonds of her pointed quotation marks. And to hear her take her rapier punctuation to the truisms around food, bodies, and exertion is to feel the wires loosen in your head. Quote-unquote overeat. How could these slippy-slidey phonemes about diet culture and the body ever have had any moral sway over me?

Pulling the pins out of tenacious cultural conceits can start anywhere. You can confront what seem like immovable beliefs about justice, nationhood, money, almost anything—and find they’re not as solid as they seem. I finally took in, on Food Psych, the idea that body size and food consumption might, just might, not be the be-all and end-all of health and well-being, and that worrying about body size and food consumption—and haphazardously dieting in sync with those worries—might be compromising, rather than improving, my life.

Another important component of freeing oneself from diet mentality is, like it or not, Instagram. It seems that skipping the notorious thin­spiration accounts, which show skeletal bodies to inspire dieters, and instead following feeds that show portraits and selfies of people in bigger bodies opens the eyes. Cellulite—that invented disease—comes to seem somehow lacy, as writer Brianna Snyder puts it. Bat wings and saddlebags and muffin tops—gaze long enough and it just happens: Those bodies come to appear beguiling, nurturing, aspirational. You start to crave ease rather than emaciation.

But even if you can warm up to the idea of beauty at any weight, what do you do about eating? Isabel Foxen Duke, an especially acerbic diet critic, has one powerful suggestion. Never eat anything while resolving not to eat it ever again. With this, she submits another word for deconstruction: “tomorrow.” Anytime you’re eating something while telling yourself you’re not going to do this tomorrow, she says, you’re in peril of mental poisoning. Probably you’re pumping out sickening cortisol, but at the very least you’re pumping out thoughts: What I’m doing now is shameful, horrible, “unhealthy,” and I won’t do it tomorrow. When you do, you deepen your own sense that you can’t be trusted, that your appetites are excessive, thereby interfering with the dynamics of tasting, swallowing, digesting, and even liking food.

Definitely radical. Maybe too radical. For those of us who have come to believe we’d fall off the edge of the earth if we ate freely, what can we truly expect from renouncing dieting? The answer from Foxen Duke is simple: If you’ve been seriously restricting, your body may become bigger. If you’ve been bingeing in response to earlier deprivation (a “diet”), your body may become smaller. In either case, you’ll see that the pounds of flesh you’ve given your years and money and work to losing and gaining and losing and gaining are hardly catastrophic. They may even be lacy.


This article was originally published in Wired. Read the original article.

Why Forgetfulness Might Actually Help You

Why Forgetfulness Might Actually Help You

Many people worry that forgetting names, facts or tasks on their to-do list is a sign of aging or mental decline.

A growing body of research offers a more welcome excuse: Forgetting stuff can actually be a byproduct of rigorous thinking, smooth decision-making or heightened creativity.

Forgetting can help us block out useless or outdated information and keep us from fixating on a single set of ideas or thoughts. And contrary to the notion that forgetfulness reflects a withering of brain cells, scientists say it can actually be driven by the growth of new neurons in the hippocampus, a brain region linked to memory.

This doesn’t excuse major memory mishaps. It’s a problem to draw a mental blank when making a presentation, forget to pick up a co-worker you promised a ride or offend a client by spacing out on a critical rule of etiquette. And of course, purposeful forgetting doesn’t include the kind of extensive memory loss that comes with dementia or similar health problems.

Still, forgetting can serve a purpose, enabling us to think more clearly by eliminating interference from competing thoughts.

This pattern is called retrieval-induced forgetting. It’s directed in part by the prefrontal cortex, which controls executive functions involved in mental control and decision-making. It makes it easier to access memories that get used a lot, and more difficult to retrieve memories that compete with them, says Michael C. Anderson, a professor of cognitive neuroscience at the University of Cambridge in England and a leading researcher on the topic.

He likens the process to search-engine optimization for the brain. “The brain balances remembering and forgetting gracefully to facilitate optimal use of memory,” Dr. Anderson says.

Understanding that people’s memories are malleable can be helpful to managers. After one of Susan Weinschenk’s consulting teams had a bad experience with a difficult client, she called team members together for a debriefing and listened to their frustrations. Then, she encouraged them to turn their focus to what they could learn from the experience, and to parts of the project that turned out better because of their work. “Now, you can move on,” Dr. Weinschenk, a behavioral scientist and consultant at The Team W in Edgar, Wis., told them.

The discussion changed how employees remembered the project. “Now when the name of that client comes up, we remember the lessons instead of the bad feelings. And we’re able to laugh about it,” she says.

The mind also tends to suppress memories that are irrelevant at the moment.

The brain undertakes a building process to accomplish this. Mice trained to find a certain location in a maze have an easier time forgetting the training and learning a new route if researchers induce neurogenesis, or growth of new neurons in the brain, when they’re trained to find a different location, says Paul Frankland, a senior scientist at the Hospital for Sick Children, an affiliate of the University of Toronto, and co-author of a 2017 research review on the topic. Researchers believe a similar process occurs in humans.

Novelist Jill Shalvis sometimes becomes so immersed in the creative process that she forgets to make sure her shoes match when she leaves home.
Novelist Jill Shalvis sometimes becomes so immersed in the creative process that she forgets to make sure her shoes match when she leaves home. PHOTO: ZRSTUDIOS

Eliminating unneeded details from memory makes it easier to draw general conclusions and spot abstract patterns based on our experiences. A manager might forget that an employee missed a meeting if the rest of her team was there, for example, making it easier to remember more important takeaways, such as the meeting’s outcome.

“Our memory systems didn’t evolve to be good at Trivial Pursuit or ‘Jeopardy!’ but to enable us to be smart about how we think and act,” says Blake Richards, assistant professor of neuroscience and machine learning at the University of Toronto and co-author with Dr. Frankland of the 2017 research review.

Forgetting prevents a memory problem called interference, which causes you to recall incorrect information because it’s similar to the memory you want, Dr. Richards says. This happens when, say, you mix up the names of people who play similar roles—calling your current intern, whose name is Matt, by the name of your intern last year, Mike, or when you suffer the tip-of-the-tongue syndrome, unable to recall a word or name because your memory of a similar one is blocking it.

Forgetting also helps solve another thinking problem called fixation, or a blind adherence to ideas, solutions or designs that already exist.

By clearing the mind of past patterns and practices, forgetting can make way for breakthrough thinking, says Benjamin Storm, an associate professor of psychology at the University of California, Santa Cruz, and co-writer of numerous studieson the role of memory and forgetting in creative thinking. “One of the biggest obstacles to thinking of something new and different is our old ideas, our current perspective and things we already know. Forgetting is at the heart of getting around that,” he says.

Michele Woodward forgot about a blog post she wrote a year ago until recently, when a friend posted it a second time on Facebook. Looking back, she’s glad it slipped her mind, because her lapse in memory freed her to write another post recently on the same topic, finding meaning in daily life, in an entirely fresh, new way. “Sometimes forgetting is an opportunity to create something new,” says Ms. Woodward, a Washington, D.C., executive coach.

Deep concentration can temporarily erase irrelevant details from the mind. Novelist Jill Shalvis sometimes becomes so consumed by writing and creating scenes in her mind that she leaves her house wearing her sweater inside-out or shoes that don’t match. When a checkout clerk at the grocery store pointed out her mismatched flip-flops, Ms. Shalvis’s teenage daughter piped up, explaining that her mother’s shoes never match when she’s on deadline.

“I have gone outside to walk the dog and forgotten to take the dog,” says Ms. Shalvis, who lives near Lake Tahoe in California, and owns two Labrador retrievers with her husband. “When I’m on deadline, I can forget what I’m doing while I’m doing it.”

Thinking hard about ideas or problems also can disrupt your ability to remember why you decided to do some other, less-important chore or task, says Chris Bailey, author of “Hyperfocus,” a book on staying productive amid distractions.

He sometimes finds himself walking into his kitchen and realizing he’s forgotten the reason he wanted to go there in the first place—such as picking up a grocery list from the table. “It’s usually a sign that I need to let my mind wander a little, and carve out more space to process that problem or decision,” he says.


This article was originally published in The Wall Street Journal. Read the original article.

Who Really Needs to Be Gluten-Free?

Who Really Needs to Be Gluten-Free?

The gluten-free craze is unlikely to go away anytime soon. Many people say they feel better after adopting a diet free of gluten, a protein found in wheat, barley and rye, even though relatively few gluten avoiders have been given diagnoses of celiac disease, an autoimmune condition that can attack the intestines and other tissues when gluten is consumed.

Approximately one person in 140 is known to have celiac disease, which can remain silent for decades and become apparent at any age. The true incidence may be a lot higher. In a Denver study that followed children born from 1993 through 2004 into their teen years, 3.1 percent turned out to have celiac disease.

“That’s an unbelievable number of Americans who may be affected,” said Dr. Joseph A. Murray of the Mayo Clinic, an international expert on the disease.

While the health consequences of celiac disease have been well documented, other reasons a person’s health might be improved by avoiding gluten include a sensitivity to gluten or something else in wheat (the major source of gluten in Western diets) and the placebo effect — a genuine benefit inspired by the belief that a chosen remedy actually works.

Gluten sensitivity does not cause the intestinal and other organ damage wrought by celiac disease, although people with it tend to experience an array of symptoms. The health of three members of my family with non-celiac gluten sensitivity improved significantly when they eliminated gluten; one, who had struggled in vain for nearly a decade to lose weight, lost 40 pounds easily when she cut gluten from her diet.

Despite the current focus on gluten, there are probably many people walking around with celiac disease who don’t know they have it. The disorder can induce a host of vague and often confusing symptoms, the true cause of which may not be determined for a decade or longer. Among possible symptoms: abdominal pain, bloating, gas, chronic diarrhea, or constipation; chronic fatigue, anemia, unexplained weight loss, or muscle cramps; missed periods, infertility or recurrent miscarriage; vitamin deficiencies, discolored tooth enamel, bone loss and fractures.

Some people assume that the way they feel is normal and never mention their distress to a doctor, or if they do, doctors may dismiss the complaints as “nothing to worry about” or attribute them to another cause.

The fact is, however, that celiac disease can remain silent for many years, during which time hidden damage can occur with lifelong, sometimes irreversible, health effects. And as a report for the United States Preventive Services Task Force that reviewed the evidencerecently stated, many of these “adverse health consequences” are “potentially avoidable.”

These factors suggest that a screening program to detect hidden disease might be health-saving for millions of people, especially children whose growth can be impaired and who may suffer other long-term problems from undiagnosed and untreated celiac disease.

However, after a thorough review of published reports, the task force did not endorse a screening program — not because it considers the condition not serious or because there is no screening test. Rather, the task force said, there is still not enough evidence to answer “key questions related to benefits and harms of screening for celiac disease in asymptomatic individuals.”

Among the areas that need more research, the task force concluded, are how accurate screening tests really are; whether screening and identifying people as having celiac disease can cause harm; and whether treating screen-detected disease improves the health, survival and quality of life of people who otherwise might not be treated.

The task force noted, for example, that no studies looked at the potential upside or downside of screening adults, adolescents or children who have no symptoms. The team concluded that a lot more well-designed research was needed before a screening recommendation could be justified as medically sound.

Meanwhile, millions of Americans are self-treating with gluten-free diets. This has its advantages and disadvantages. If avoiding gluten makes people feel better, if they can afford the sometimes more costly gluten-free foods, and if avoiding gluten doesn’t turn them into social pariahs, most reasonable people would say, “Why not?”

A main disadvantage of self-treatment without a diagnosis is that an accurate result of the tests for celiac disease requires that the person regularly consumes gluten. Avoiding this protein would mask a positive finding on a screening blood test and biopsy evidence of damage to the intestines that can result from eating gluten.

“There’s a simple blood test for celiac, but it must be done before you change your diet,” Dr. Murray said in an interview.

Aside from intestinal damage, failing to detect asymptomatic celiac at an early age can result in poor bone development and suppressed growth, Dr. Murray said. This can create “a high risk for fractures both before and after a diagnosis of celiac, which might not happen until age 40 or 50,” he explained.

When undiagnosed celiac results in persistent fatigue or infertility, “you can lose years of quality of life that you can’t get back,” Dr. Murray said.

If symptoms are subtle, he added, “people can be sick for so long, they don’t know what health is. They don’t recognize their symptoms and don’t complain to the doctor. If the whole population were screened and people with celiac were found and treated, it could result in no health consequences.”

That, however, would require rigorous adherence to a gluten-free diet. Without a medical diagnosis of celiac and an explanation of its possible consequences, people are likely to be less careful about what they eat.

There is also a potential medical downside to diagnosis and treatment. “Contrary to what many people think, a gluten-free diet is not necessarily a healthy diet,” Dr. Murray said. “When people with celiac go on it, they often gain weight, especially fat weight, because they are no longer malabsorbing nutrients. They are also more likely to develop metabolic syndrome,” which raises the risk of heart disease and Type 2 diabetes.

Until evidence is developed that could justify screening the entire population for celiac, Dr. Murray advocates screening “everyone in the at-risk group,” which would include family members of celiac patients and everyone with Type 1 diabetes, premature osteoporosis and anemia, which may be signs of celiac disease. He also advised that people with chronic bloating, mouth ulcers, chronic headaches or fatigue should be tested.

Others who may be at risk for celiac include people with tingling or numbness in the arms and legs, thyroid disease, rheumatoid arthritis and Sjogren’s syndrome.


This article was originally published in The New York Times. Read the original article.

Revealing the wheat genome could lead to hypoallergenic bread

Revealing the wheat genome could lead to hypoallergenic bread

ONE of the most surprising things about the announcement this week that the genome of wheat has been fully mapped is how long it has taken. As well as the human genome, a draft of which was completed in 2000, scientists have tackled everything from rice to the clearhead icefish and the black cottonwood tree. The world’s most widely cultivated crop has taken all this time because it was really difficult; the “Mount Everest” of plant genetics, according to some.

That difficulty arises from the fact that wheat is not one genome but three overlapping and similar ones, the result of natural hybridisation. It is more than five times the size of the human genome and comprises some 107,000 genes (humans have about 24,000). Genomes are generally figured out by breaking them into smaller pieces, sequencing those pieces and then working out how they fit together. With so many similar-looking sequences, the international team of researchers, whose findings were reported in Science and whose efforts focused on a variety of bread wheat called Chinese Spring, had a huge job on their hands.

Their achievement comes at an opportune time. Humans have been tinkering with wheat for almost 10,000 years, but new tools are becoming available for the precise manipulation of genomes. Gene-editing using a technique called CRISPR, along with a fully annotated genetic sequence, promises a new era in wheat cultivation, introducing traits to improve yields, provide greater pest resistance and to develop hardier varieties.

Of particular interest will be how decoding the genes might contribute to understanding, and perhaps even mitigating, various immune diseases and allergies associated with eating bread. This possibility is explored by Angela Juhász of Murdoch University, in Western Australia, and her colleagues in an associated paper in Science Advances.

Coeliac disease, for instance, is an immune reaction to eating gluten; the related genes are the glutenins and gliadins that are expressed in the starchy endosperm of the wheat grain. A different set of allergens, including amylase trypsin inhibitors found in a thin layer of cells that surround the endosperm, are implicated in an illness called baker’s asthma; these could be of concern to people who suffer non-coeliac wheat sensitivity.

One possibility is using diagnostic techniques to identify wheat varieties that contain gluten which is easier to digest, says Rudi Appels, another of the associated paper’s authors. Normally the gut can break down the large proteins found in gluten, but when this process fails and those proteins arrive in the lower gut they interact with the gut’s membrane and cause immune problems. In the future, says Dr Appels, wheat might also be fine-tuned to be less allergenic. This might be done by editing the wheat genome so that it contains more digestible proteins.

Those who have trouble with gluten may find, however, that the source of their problem lies more in the processing of bread rather than the genetics of wheat. Dr Appels says that many commercial bakers use processes that eliminate part of the traditional fermentation stage in making bread. And his guess is that this fermentation would have broken up the problematic proteins into smaller and more digestible pieces. This might explain why some coeliacs (and, indeed, some others who complain that bread is indigestible) can happily eat sourdough bread, which is still made using traditional methods.

It also seems that non-coeliac wheat sensitivity might not be due to gluten at all, but a poorly absorbed carbohydrate component of wheat: fructans and galacto-oligosaccharides, along with another allergen, the amylase trypsin inhibitors which are implicated in activating the innate immune system. Again, fermented bread may have fewer of these hard-to-digest bits. Now that scientists have the genome, such theories should be easier to prove.



This article was originally published in The Economist. Read the original article.

Large Study Identifies Genetic Variants Linked to Risk Tolerance and Risky Behaviors

Large Study Identifies Genetic Variants Linked to Risk Tolerance and Risky Behaviors

An international group that includes researchers at University of California San Diego School of Medicine has identified 124 genetic variants associated with a person’s willingness to take risks, as reported in a study published January 14 in Nature Genetics .

The researchers emphasize that no variant on its own meaningfully affects a particular person’s risk tolerance or penchant for making risky decisions — such as drinking, smoking, speeding — and non-genetic factors matter more for risk tolerance than genetic factors. The study shows evidence of shared genetic influences across both an overall measure of risk tolerance and many specific risky behaviors.

The genetic variants identified in the study open a new avenue of research on the biological mechanisms that influence a person’s willingness to take risks.

“Being willing to take risks is essential to success in the modern world,” said study co-author Abraham Palmer, PhD, professor of psychiatry and vice chair for basic research at UC San Diego School of Medicine. “But we also know that taking too many risks, or not giving enough weight to the consequences of risky decisions, confers vulnerability to smoking, alcoholism and other forms of drug addiction.”

The genetic variants identified in this study open a new avenue of research on the biological mechanisms that influence a person’s willingness to take risks. Photo courtesy of Pixabay

Palmer’s lab, which includes co-author Sandra Sanchez-Roige, PhD, is working to understand the genetic basis of individual differences in impulsive and risky decision-making styles. They want to understand the fundamental molecular and cellular processes that shape human behavior, and learn how to prevent and treat drug abuse.

“Risk-taking is thought to play a role in many psychiatric disorders,” said co-author Murray Stein, MD, MPH, Distinguished Professor of in the departments of Psychiatry and Family Medicine and Public Health, and vice-chair for clinical research in psychiatry at UC San Diego School of Medicine. “For example, patients with anxiety disorders may perceive increased risk in certain situations and therefore avoid them unnecessarily. Understanding the genetic basis for risk tolerance is critical to understanding these disorders and developing better treatments.”

The team measured participants’ overall risk tolerance based on self-reports. They found that genetic variants associated with overall risk tolerance tend to also be associated with more risky behaviors, such as speeding, drinking, tobacco and cannabis consumption, and with riskier investments and sexual behaviors. They also found shared genetic influences on overall risk tolerance and several personality traits and neuropsychiatric traits, including ADHD, bipolar disorder, and schizophrenia.

The effects of each of the 124 genetic variants on an individual basis are all very small, but the researchers found their combined impact can be significant.

“The most important variant explains only 0.02 percent of the variation in overall risk tolerance across individuals,” said senior author Jonathan Beauchamp, PhD, assistant professor of economics at the University of Toronto. “However, the variants’ effects can be combined to account for greater variation in risk tolerance.”

The researchers created a polygenic score, which captures the combined effects of 1 million genetic variants and statistically accounts for approximately 1.6 percent of the variation in general risk tolerance across individuals. They say the score could be used to study how genetic factors interact with environmental variables to affect risk tolerance and risky behaviors, but they caution that the score cannot meaningfully predict a particular person’s risk tolerance or risk taking behavior.

The 124 genetic variants associated with risk tolerance are located in 99 separate regions of the genome. The study found no evidence to support previously reported associations between risk tolerance and genes related to the neurochemicals dopamine or serotonin, which are involved in the processing of rewards and mood regulation.

Instead, the findings suggest that the neurochemicals glutamate and GABA contribute to variation in risk tolerance across individuals. Both are important regulators of brain activity in humans and animals — glutamate is the most abundant neurotransmitter in the body and boosts communication between neurons, whereas GABA inhibits it.

“Our results point to the role of specific brain regions — notably the prefrontal cortex, basal ganglia and midbrain — that have previously been identified in neuroscientific studies on decision-making,” Beauchamp said. “They conform with the expectation that variation in risk tolerance is influenced by thousands, if not millions, of genetic variants.”

The data for this study were from the UK Biobank, the personal genomics company 23andMe, and 10 other, smaller genetic datasets.

The study was led by 96 researchers in the Social Science Genetic Association Consortium, which investigates the influence of genetics on human behavior, well-being and social science-related outcomes through large-scale studies of human genomes.

What’s Going On In Your Child’s Brain When You Read Them A Story?

What's Going On In Your Child's Brain When You Read Them A Story?

“I want The Three Bears!”

These days parents, caregivers and teachers have lots of options when it comes to fulfilling that request. You can read a picture book, put on a cartoon, play an audiobook, or even ask Alexa.

newly published study gives some insight into what may be happening inside young children’s brains in each of those situations. And, says lead author Dr. John Hutton, there is an apparent “Goldilocks effect” — some kinds of storytelling may be “too cold” for children, while others are “too hot.” And, of course, some are “just right.”

Hutton is a researcher and pediatrician at Cincinnati Children’s Hospital with a special interest in “emergent literacy” — the process of learning to read.


For the study, 27 children around age 4 went into an FMRI machine. They were presented with stories in three conditions: audio only; the illustrated pages of a storybook with an audio voiceover; and an animated cartoon. All three versions came from the Web site of Canadian author Robert Munsch.

While the children paid attention to the stories, the MRI, the machine scanned for activation within certain brain networks, and connectivity between the networks.

“We went into it with an idea in mind of what brain networks were likely to be influenced by the story,” Hutton explains. One was language. One was visual perception. The third is called visual imagery. The fourth was the default mode network, which Hutton calls, “the seat of the soul, internal reflection — how something matters to you.”

The default mode network includes regions of the brain that appear more active when someone is not actively concentrating on a designated mental task involving the outside world.

In terms of Hutton’s “Goldilocks effect,” here’s what the researchers found:

In the audio-only condition (too cold): language networks were activated, but there was less connectivity overall. “There was more evidence the children were straining to understand.”

In the animation condition (too hot): there was a lot of activity in the audio and visual perception networks, but not a lot of connectivity among the various brain networks. “The language network was working to keep up with the story,” says Hutton. “Our interpretation was that the animation was doing all the work for the child. They were expending the most energy just figuring out what it means.” The children’s comprehension of the story was the worst in this condition.

The illustration condition was what Hutton called “just right”.

When children could see illustrations, language-network activity dropped a bit compared to the audio condition. Instead of only paying attention to the words, Hutton says, the children’s understanding of the story was “scaffolded” by having the images as clues.

“Give them a picture and they have a cookie to work with,” he explains. “With animation it’s all dumped on them all at once and they don’t have to do any of the work.”

Most importantly, in the illustrated book condition, researchers saw increased connectivity between — and among — all the networks they were looking at: visual perception, imagery, default mode and language.

“For 3- to 5-year-olds, the imagery and default mode networks mature late, and take practice to integrate with the rest of the brain,” Hutton explains. “With animation you may be missing an opportunity to develop them.”

When we read to our children, they are doing more work than meets the eye. “It’s that muscle they’re developing bringing the images to life in their minds.”

Hutton’s concern is that in the longer term, “kids who are exposed to too much animation are going to be at risk for developing not enough integration.”

Overwhelmed by the demands of processing language, without enough practice, they may also be less skilled at forming mental pictures based on what they read, much less reflecting on the content of a story. This is the stereotype of a “reluctant reader” whose brain is not well-versed in getting the most out of a book.

One interesting note is that, because of the constraints of an MRI machine, which encloses and immobilizes your body, the story-with-illustrations condition wasn’t actually as good as reading on Mom or Dad’s lap.

The emotional bonding and physical closeness, Hutton says, were missing. So were the exchanges known as “dialogic reading,” where caregivers point out specific words or prompt children to “show me the cat?” in a picture. “That’s a whole other layer,” of building reading Hutton says.

In an ideal world, you would always be there to read to your child. The results of this small, preliminary study also suggest that, when parents do turn to electronic devices for young children, they should gravitate toward the most stripped-down version of a narrated, illustrated ebook, as opposed to either audio-only or animation.


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How Deepak Chopra, Wellness Expert, Spends His Sundays

How Deepak Chopra, Wellness Expert, Spends His Sundays

Dr. Deepak Chopra, the alternative medicine and New Age megastar, spends his Sundays meditating, walking, and contemplating life. “Sunday is a day of reset. It’s not a day of obligations,” he said. “There’s nothing that important if you miss it.” For the past five years Dr. Chopra, 72, and his wife of 48 years, Rita, 70, have lived in a luxury green apartment, complete with vitamin-filtered showers and antimicrobial coating on high-touch areas, in Union Square, Manhattan. “The air and water are filtered,” Dr. Chopra added, and “there’s no outside sound.” This year he will introduce a podcast on the Cadence13 podcast network and is on schedule to finish his 89th book.

GENTLE START I’m up at 5 a.m. I’m a morning person. We have circadian lighting in the bedroom, which changes from total darkness to pre-dawn to morning light. Then I stare at the ceiling for 10 minutes doing nothing.

Relaxing in his anti-gravity chair.CreditHaruka Sakaguchi for The New York Times

Relaxing in his anti-gravity chair.CreditHaruka Sakaguchi for The New York Times

STILLNESS For the next two hours I sit in bed and meditate. When my wife wakes, she meditates with me. Then I practice body and breath awareness while asking myself, “How can I have the most joyful day?”

STRETCH From 7:30-8:30 I do standard yoga. Three times a week I go to a class in the building. Right now I’m using a purple mat someone gave me. It has my name on it. People keep giving me mats. I have six or seven of them.

“Everyday reality is a lucid dream and I reflect on that. Then I detach from it and let it go.”CreditHaruka Sakaguchi for The New York Times


“Everyday reality is a lucid dream and I reflect on that. Then I detach from it and let it go.”CreditHaruka Sakaguchi for The New York Times

DOCTOR’S ORDERS I make coffee and drink three cups before noon. Then, no coffee after that. I used to have only one, but my brother, who’s a doctor, convinced me to have more. He thinks everyone should have five cups, but that’s too much.

GETTING THEIR STEPS IN Around 9:30 my wife and I take a two-hour walk. We do Central Park or ride the subway to Queens or Brooklyn. I specifically go to ethnic neighborhoods like Chinatown and Little India because it’s different. I enjoy sensory experiences like color, taste, and people. Living in New York is like living in the rest of the world. We walk a minimum of 10,000 steps. Usually it’s 20,000, or 5 to 10 miles.

Keeping up with his people via Facebook Live.CreditHaruka Sakaguchi for The New York Times


Keeping up with his people via Facebook Live.CreditHaruka Sakaguchi for The New York Times

MEAL SELECTION First we decide if we’re going to have a big lunch or dinner. I only have one big meal a day. I leave that to my wife. I’m not a foodie but I know every restaurant in the neighborhood. I love anything that’s different from our own Indian cooking, which my wife will do if the kids are here.

ALONE TIME I’m not a social person. I’m alone a lot because my wife has many interests. She loves to go to movies and museums. She’s learned to do it by herself when her friends can’t join her.

Mr. Chopra’s bathroom has circadian lighting.CreditHaruka Sakaguchi for The New York Times


Mr. Chopra’s bathroom has circadian lighting.CreditHaruka Sakaguchi for The New York Times

BOOKS For the next two hours I work on my new book, “Meta Human.” This will be my 89th. I’m going to write one more and then I’m done. I’m juggling 20 different books because they pertain to what I’m writing. I go on the internet and will find a title that’s tantalizing, like “You Are Not Your Brain.” Right now I’m reading two from the Israeli historian Yuval Noah Harari, “Sapiens” and “Homo Deus.” He tracks our existence to the Big Bang. Also “Wings of Death: The Last Poems of Rabindranath Tagore,” which is inspiring. I’m obsessed with death these days.

PREP I write or jot down notes that have been incubating in my head for the next 30 minutes. Or I prepare for a talk I’m giving.

Visiting the Strand bookstore during one of his daily strolls.CreditHaruka Sakaguchi for The New York Times


Visiting the Strand bookstore during one of his daily strolls.CreditHaruka Sakaguchi for The New York Times

LET IT GO From 5 to 5:30 I do a second, short meditate on the day that has passed by, which I do in my gray chair. Everyday reality is a lucid dream, and I reflect on that. Then I detach from it and let it go. Experience is ungraspable. It’s all snapshots.

CATCH-UP My wife comes home. We talk about each other’s day. Mine was not as interesting as hers. She updates me about what she did and who she saw.

“Experience is ungraspable. It’s all snapshots.”CreditHaruka Sakaguchi for The New York Times


“Experience is ungraspable. It’s all snapshots.”CreditHaruka Sakaguchi for The New York Times

SNACK I don’t eat after sunset, so I’ll have a small meal, yogurt or an everything bagel with cream cheese, or lentil soup.

WALK AND REFLECT From 7 to 7:30 I may take a second walk by myself. I’m a loner. I don’t have a social life. I try not to reflect during this time. To just be and enjoy the sound, color, neon lights or the flavors that New York assaults on your senses.

SCREENS I don’t watch TV, so from 8 to 8:30 I check the news on my computer. I look at The Times or CNN. I catch up with my emails and communicate with my kids, and grandchildren, who I might FaceTime with. I talk with them every day. It doesn’t matter where they are.

TO INFINITY AND BEYOND By 9 I get into bed and do Yoga Nidra for 10 minutes where I consciously shut off sensory experiences. I drift into the infinite, fall asleep, hoping to see the world for the first time the following day.