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Nutrition

Health and Fitness, Microbiology, Nutrition, Public Health, Research, Stanford News

Can low-fiber diets’ damage to our gut-microbial ecosystems get passed down over generations?

Can low-fiber diets' damage to our gut-microbial ecosystems get passed down over generations?

fast food decisionsUh-oh.

A study conducted in mice raises suspicions that we humans may be halfway down the road to the permanent loss of friendly gut-dwelling bacteria who’ve been our constant companions for hundreds of millennia. That’s probably not good.

Virtually all health experts agree that low-fiber diets are sub-optimal. One big reason: Fiber, which can’t be digested by human enzymes, is the main food source for the friendly bacteria that colonize our colons. Thousands of distinct bacterial species thrive within every healthy mammal’s large intestine. Far from being victimized by these colonic cohabitants, we’d be hard put to live without them. They fend off pathogens, train our immune systems, help us digest food we’d otherwise be unable to use and even guide the development of our tissues.

From a news release I wrote about the new study, which was spearheaded by Stanford microbiology/nutrition explorers  (and husband/wife team) Justin Sonnenburg, PhD, and Erica Sonnenburg, PhD, and published in Nature:

[Previous] surveys of humans’ gut-dwelling microbes have shown that the diversity of bacterial species inhabiting the intestines of individual members of hunter-gatherer and rural agrarian populations greatly exceeds that of individuals living in modern industrialized societies. … In fact, these studies indicate the complete absence, throughout industrialized populations, of numerous bacterial species that are shared among many of the hunter-gatherer and rural agrarian populations surveyed, despite those groups’ being dispersed across vast geographic expanses ranging from Africa to South America to Papua New Guinea.

Another piece of information: The proliferation of nearly fiber-free, processed convenience foods since the mid-20th century has resulted in average-per-capita fiber consumption in industrialized societies of about 15 grams per day. That’s as little as one-tenth of the intake among the world’s dwindling hunter-gatherer and rural agrarian populations, whose living conditions and dietary intake presumably most closely resemble those of our common human ancestors.

Perhaps the most significant sources of our intestinal bacterial populations is our immediate family, especially our mothers during childbirth and infancy. So, if our low-fiber diets are depleting our intestinal ecosystems, could that depletion get passed down from one generation to the next?

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Health and Fitness, In the News, Nutrition, Pediatrics

Teens need healthy brain food, says Stanford expert

Teens need healthy brain food, says Stanford expert

teens-healthy-foodToday, U.S. News and World Report released their 2016 ranking of the best diets. For their story on healthy eating for teenagers, Neville Golden, MD, division chief of adolescent medicine at Lucile Packard Children’s Hospital Stanford, explained how diet can affect teens’ brains and moods:

Teens are faced with myriad physical changes and academic demands, all while being bombarded by what their peers are doing – from what not to wear, to what to say and when to say it, to how to get the attention of you know who. And in the midst of all this, the body’s most critical organ – the brain –is still developing, says Dr. Neville Golden, a member of the American Academy of Pediatrics’ Committee on Nutrition…

“If [teens] don’t eat right, they can become irritable, depressed [and] develop problems such as obesity and eating disorders – and those have a whole host of psychological morbidities,” Golden says, adding that proper nutrition can help prevent and manage these conditions.

The rest of the story provides lots of specifics on how teens can improve their diets, including a sample menu for a day of healthy eating. If you know a teen who has made a nutritious New Year’s resolution, it’s definitely worth sharing.

Previously: Want teens to eat healthy? Make sure they get a good night’s sleep, Living near fast food restaurants influences California teens’ eating habits and British teens not getting enough fruits, veggies
Photo by Nestlé

Global Health, Nutrition, Obesity, Parenting, Rural Health

Chinese children face obesity risk

Chinese children face obesity risk

69186639_e78742d08a_zWith the parents gone away, the children have time to play — and eat, according to new research that examines the health of the millions of Chinese children left with families when their parents move to urban centers.

Researchers from the University of Manchester in England analyzed the dietary choices of 975 children from 140 rural villages. Led by graduate student Nan Zhang, the team found children living with their grandparents or a single parent ate more fat and less protein than children living with two parents. The research appeared in Public Health Nutrition.

The diets of boys particularly worsened, a finding that has complex implications in a society where males are favored, Zhang said in a news release.

The study did not examine why the childrens’ diets changed, but Zhang has several theories. From the release:

The researchers speculate that mothers moving away from home generally earn less, and that these lower earnings act in combination with grandparents’ poorer dietary knowledge or willingness to spend more on food…

Another factor at work could be that prices of protein-based foods such as eggs and meat have increased faster than many households’ incomes.

The study highlights the need for increased public education on nutrition, she said.

Previously: Building the case for a national hepatitis B treatment program in China, Seeking solutions to childhood anemia in China and  “We should act now”: Stanford expert calls for more targeted anti-obesity policies
Photo by T Chu

Education, Nutrition, Public Health, Research, Stanford News, Videos

Online Stanford nutrition course improves participants’ eating habits, study finds

Online Stanford nutrition course improves participants' eating habits, study finds

I’m a big fan of Stanford’s free online course on child nutrition and cooking. And it’s not just me: Since the course launched in early 2014, more than 200,000 people have enrolled and watched the quick, informative, charming videos about understanding nutrition and making healthy food for kids. My favorite video, above, shows how to cook toad-in-a-hole, a comfort food I’ve loved since my own childhood.

Recently, instructor Maya Adam, MD, and her colleagues tested the effect of completing the course. When they designed the course, they hoped it would improve participants’ eating habits. A few other institutions had seen promising results from smaller online nutrition courses, but none of those combined nutrition instruction with hands-on demos of how to actually put their advice into practice in the kitchen. Yet other research suggests that making this connection between the “why” and “how” of healthy eating is important, since many people say that their lack of cooking know-how keeps them from eating well.

The results of the study, which appears in the International Journal of Behavioral Nutrition and Physical Activity, showed that the course is a success. Based on data from 7,422 participants surveyed about their eating habits before and after taking the course, the material presented helped participants cook fresh foods at home more often and eat more fresh fruits and vegetables. After the course, participants were also more likely to say that their previous day’s dinner was enjoyable and healthy.

“This is part of a growing body of research suggesting that just learning to cook can lead to improved dietary intake, which has amazing implications for public health interventions aimed at preventing overweight and obesity,” Adam told me in an e-mail.

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Health and Fitness, Nutrition, Parenting

How parents and kids can have a happier – and healthier – Halloween

How parents and kids can have a happier - and healthier - Halloween

Tangarine pumpkin 560x372When I was a kid, the ghosts and ghouls of Halloween were the scariest things around. Now that I’m older, the terrors of Halloween have taken on a different form: Pumpkin-shaped pails that put fun-sized candies within easy reach, Halloween-themed cupcakes and cookies too cute to be “bad” for you and bulk bags of holiday treats at bargain prices.

If you’re a parent who’s trying to maintain a healthy lifestyle for your kids and yourself, these treats can quickly eat away all the hard work you put into developing healthy diet habits. So how can you get through this season of excess eating unscathed? On the Healthier, Happier Lives Blog, Shiri Sadeh-Sharvit, PhD, a clinical psychologist with Stanford’s Eating Disorders Research Program, offers these tips:

Be flexible

Parenting is all about flexibility. Just as you plan on going on a trip, but something happens and you find yourself modeling to your children how you adapt to a changing environment, Halloween is not a challenge most parents have not dealt with thus far. You have probably spoken in the past with your child about how your habits and preferences as a family may be different from their friends’; you have likely taught them about the food pyramid and how different foods affect their bodies; and you have already experienced making decisions that your kids did not like.

Know your limits

A possible approach to Halloween is comprised of first knowing your limits – how many sweets and candies you think would be OK for your child? The answer may change according to your child’s age. For younger children, providing smaller baskets, allowing only a few treats during Halloween and saving a few treats for the following weeks would be acceptable. With older children, you can discuss their ideas and understandings how to go about the sweet celebration.

Recognize there’s more to Halloween than food

When you and your children have a clearer understanding of your approach to Halloween, take this external opportunity to have fun! Wear a costume, extend your “persona” boundaries, and enjoy the non-food parts of this wonderful celebration. After all, isn’t this what Halloween is all about?

Previously: Eat well, be well and enjoy (a little) candyTips from a doctor (and a mom) for a safe Halloween and How to avoid a candy-coated Halloween
Photo by Pietro Bellini

Nutrition, Parenting, Pediatrics

Forget perfection and just cook for your kids, says new book by Stanford author

Forget perfection and just cook for your kids, says new book by Stanford author

Maya Adam at farmers market“Our children are in trouble because we’ve outsourced the job of feeding them,” says Stanford child nutrition expert Maya Adam, MD.

To tackle the problem, Adam is spreading a refreshing message: Forget celebrity-chef culture and food fads, and just cook for your kids. Eat real food and enjoy it. Don’t worry about perfection. Help your children learn to love healthy foods that will love them back.

Over the last few years, as the instructor of a wildly popular online nutrition and cooking course and through the nonprofit she founded, Adam has shared her common-sense approach with thousands of people. Now she has a book, Food Love Family: A Practical Guide to Child Nutrition, which builds on those messages with stories about how parents around the world find a healthy approach to feeding their kids.

“My goal was to translate scientific research on nutrition and children’s health, and make it something parents could turn into practical success,” Adam told me when I called to chat about her new book. An edited version of our conversation is below.

Your book suggests we focus more on whole foods and less on individual nutrients. Why is that important for parents to hear?

Traditionally, nutrition science is reductionist – it has focused on individual nutrients because that’s how scientists study them. But it doesn’t necessarily translate to action for parents, because we eat food, not nutrients. The book is about making that link, translating science into helpful strategies parents could implement with their families.

In childhood, we have this unique opportunity to create a situation where the foods kids enjoy most are the foods that will support them throughout their lives. If we can do that, then we’ve won: We never have to re-train them later when they’re pre-diabetic or struggling with their weight and say, “You’re no longer allowed to eat the foods you’ve grown to love.” Instead, their whole lives they love the right things.

You’ve written about the fact that our culture has built cooking up into an extreme sport, not to be attempted by amateurs — and that scares people off. If you heard from a parent who said, “OK, you’ve convinced me to overcome my fear of cooking, but I need an easy place to start,” what would you tell them?

At the end of the book, we’ve included very simple recipes, all of which tie back to our free online course with videos that show the recipes in action. It’s part of a system of support for parents. If they’re visual learners and want to see someone doing it – how to crack an egg while holding a young child on your hip, for instance – we have that.

Cooking for your family is not about being perfect; it’s about being real, about doing just a little more than you’re doing now. We all have to do the best we can with the resources that are available. Maybe we can’t always afford the grass-fed beef, for instance, but that’s OK. We do what we can with the time, skills and financial resources we have.

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FDA, Health Policy, Nutrition, Pediatrics, Public Health, Research, Stanford News

How much Bisphenol A is okay?

How much Bisphenol A is okay?

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A new study came out this week that happened to remind me of one of my pet peeves about certain biomedical studies — choosing an “outcome” measure that doesn’t tell you what you really want to know. The study, which was led by Stanford postdoctoral fellow Jennifer Hartle, DrPH, and estimated the amount of BPA a child is exposed to in the course of a normal school day, was great. But her description of EPA safety tests on the plastics component Bisphenol A, or BPA — done back in the 1980s — made me think back to earlier work by University of California, Berkeley biologist Tyrone Hayes, PhD.

In the 1990s, the agricultural herbicide atrazine was safety tested by exposing frogs to low doses of atrazine as they developed from eggs to tadpoles to frogs. The adult frogs didn’t die or show obvious deformities such as extra legs, so the pesticide was deemed safe. But Hayes took a closer look and, in 2002, found that even at very low levels of atrazine exposure, male frogs were producing eggs instead of sperm.

So no gross deformities if you just looked at the frogs for 30 seconds. But in fact the animals had experienced a dramatic change in their health and biology. The lesson is that, in biology, sometimes the right outcome measure is something you have to really look for. There is a lot more to the Hayes-atrazine story.

But back to the current study: Hartle and her colleagues turned their attention to national school breakfast and lunch programs, which provide nutritious meals to 30 million kids every year but also deliver small amounts of BPA, an estrogen mimic that messes with hormones. Children’s meals are disproportionately packaged in tiny one-meal containers. Those tiny packages of apple sauce and juice have a greater BPA-emitting surface area than a big carton or can for the amount of food. And school kids often eat meals off plastic trays with plastic forks and spoons. For children who eat a lot of meals at school, it can add up.

According to Hartle’s paper, appearing today in the Journal of Exposure Science and Environmental Epidemiology, the question isn’t whether the kids are getting BPA in their meals — they are — but whether any of them are getting doses of BPA that could affect their long-term health. Based on those 1980s studies, the EPA estimates that BPA is safe at chronic exposure levels below 50 μg per kilogram of body weight per day. Happily, Hartle and her colleagues found that children are getting far less than that — as little as 0.0021 μg for a low-BPA breakfast to 0.17 μg for a high-BPA lunch. Everything should be hunky-dory, right?

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In the News, Medicine and Society, Nutrition, Parenting, Research, Women's Health

Research elaborates on how moms can protect their daughters’ body image

Research elaborates on how moms can protect their daughters' body image

6945839301_9d61091329_zIt’s been my experience that women struggle with their body image at some point on the way from girlhood to womanhood – this may be brief and exploratory, or get tangled with eating disorders and other destructive behaviors. When I had a period of bulimia in my early 20s, I reflected on (among other things) my mother’s relationship with food and body image, and so some new research from Ben-Gurion University in Israel struck a chord.

Maia Maor, PhD, a sociologist, and Julie Cwikel, PhD, a professor of social work and director of the Center for Women’s Health Studies and Promotion, invited adult mother-daughter pairs to reflect on various strategies the mothers used to instill resilience about body image in their daughters. The researchers identified five methods commonly used to resist or reject negative and oppressive messages about body image:

  1. Filtering: being cautious and sensitive regarding body image issues 
  2. Transmitting awareness of the dangers of eating disorders, which can cause illness and death
  3. Positive reinforcement, using affirmative language in regard to their daughters’ bodies
  4. Discussion: providing tools for criticism of dominant body-related messages
  5. Positivity: shifting the focus of food and body-related discussions away from weight loss and towards health and taking pleasure in food. 

In a press release from last week, Maor explained that “the focus on protective strategies was intended to achieve two goals: to emphasize the positive in mother-daughter relationships and to identify a repertoire of strategies available to parents and allied health professionals who wish to help their daughters or young women build a stable, positive body image.”

Feelings about food and bodies have long chains of intergenerational transmission. According to the release, “some of the mothers in the study recalled how their own mothers’ negative comments to them about eating too much led them to associate food with guilt and bad feelings. They raised their own daughters by instead talking about the quality of food, importance of food choices and its relationship to developing respect for their own bodies.”

The study appears in the journal Feminism & Psychology.

Previously: Incorporating the family in helping teens overcome eating disorders, Stanford study investigates how to prevent moms from passing on their eating disorders, Promoting healthy eating and a positive body image on college campuses, What a teenager wishes her parents knew about eating disorders, and Social website shown to boost teen girls’ body image
Photo by Thanasus Anastasiou

Chronic Disease, Health and Fitness, In the News, Nutrition, Obesity, Stanford News

A conversation about the diabetes epidemic

A conversation about the diabetes epidemic

On this morning’s KQED’s morning radio show, Forum, several doctors including Stanford’s Bryant Lin, MD, discussed how diabetes is affecting the health of millions of people globally.

A recent study in the Journal of the American Medical Association estimated that about half of all adults have diabetes (diagnosed or undiagnosed) or pre-diabetes. Lin and his fellow panelists talked about how changes in our diet and lifestyle have fueled the number of diabetic cases, as well as how genetics can tip the odds against certain patients. Lin mentioned that Asians have a higher rate of diabetes than whites, for example.

Like Lin, I have a family history of diabetes. (Like Lin, I’ve also struggled to maintain my weight). That history has made me keenly interested in staying abreast of recent findings about diabetes – and I surprised to hear that among young people, high rates of liquor consumption is influencing diabetes rates. It’s not just soda intake that we have to watch out for.

Another surprising finding that Lin described was that for pre-diabetics, taking Metformin, a drug that helps control diabetes and blood sugar, can help stave off full-blown diabetes. Eventually, it may become routine to prescribe this medication in certain populations, but Lin said that guidelines haven’t caught up with this aspect of diabetes care.

Other factors at play, Lin noted, include the role of the microbiome in promoting or protecting people from diabetes. And people who undergo bariatric surgery for weight management often find their diabetes is cured, but doctors don’t understand exactly why that’s the case.

Despite the staggering number of people affected, it’s clear that we still don’t understand all the complex factors that influence this disease.

Previously: Faulty fat cells may help explain how Type 2 diabetes beginsThe role of nutrition in diabetes prevention and managementThe importance of regular exercise in delaying and treating diabetes and Examining the role of exercise in managing and preventing diabetes

Nutrition, Obesity, Research

A call to focus on the nutritional value of foods, rather than calorie counts

A call to focus on the nutritional value of foods, rather than calorie counts

10331709463_60f2188a69_zTo reduce obesity rates, cardiovascular risk and chronic diseases, ditch calorie counting and instead emphasize the nutritional content of foods. That’s the message from a group of British researchers in an editorial recently published in Open Heart.

Drawing on past scientific evidence, the authors argue that physicians, patients and society’s focus on low-calorie foods and diets has resulted in a sacrifice of good nutrition and failed to improve overall public health. According to a press release:

Daily consumption of a sugary drink (150 calories) is associated with a significantly increased risk of type 2 diabetes whereas daily consumption of a handful of nuts (30 g of walnuts, 15 g of almonds and 15 g hazelnuts) or four tablespoons of extra virgin olive oil (around 500 calories) is associated with a significantly reduced risk of heart attack and stroke.

It has been estimated that increasing nut consumption by two servings a week could stave off 90,000 deaths from cardiovascular disease in the US alone.

And the Action for Health in Diabetes trial shows that a low calorie diet on top of increased physical activity in patients with type 2 diabetes was not associated with a reduced risk of cardiovascular death despite significant weight loss and a monitoring period of 13.5 years, [the authors] point out.

“It is time to stop counting calories, and time to instead promote good nutrition and dietary changes that can rapidly and substantially reduce cardiovascular mortality. The evidence indeed supports the mantra that ‘food can be the most powerful form of medicine or the slowest form of poison’,” they write.

Previously: The trouble with the current calorie-counting system, Homemade: Community-based project teaches how to cook for health and Cooked food, calorie counts and food labels
Photo by Mariya Chorna

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