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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?


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

Health Disparities, In the News, Nutrition, Public Health

Turning brown bananas into ice cream: Repurposing surplus food reduces hunger, creates jobs

Turning brown bananas into ice cream: Repurposing surplus food reduces hunger, creates jobs

8421632884_224d355c21_zAccording to a recent report, the United States is one of the most wasteful countries in the world. Up to 40 percent of American food is thrown in the trash, which seems absurd given that food insecurity and hunger are still such problems in this country. Adequate nutrition is a basic for preventing disease and promoting health.

But students at Drexel University are working on improving the situation. They developed a program to use would-be supermarket waste in producing value-added food products. Not only can these products be provided to hungry people, they can be sold back to the supermarket in a mutually-beneficial relationship that could also support new jobs.

The strategy – called a “Food System-Sensitive Methodology”, or FSSM – was developed as part of the Environmental Protection Agency’s Food Recovery Challenge, and is described in a recent Food and Nutrition Sciences article. Drexel culinary arts and food science students decided to reach out to supermarkets because these stores are some of the biggest producers of waste: They throw out produce that is bruised, marked, or misshapen, or remove food simply to make room for fresher shipments. For their pilot project in West Philadelphia, students collected thousands of pounds of fruits and vegetables from local supermarkets and improved their value and palatability by developing recipes in the student-run Drexel Food Lab, a research group that aims to address real-world food issues.

Americans are used to cosmetically pristine produce, and many won’t eat a brown banana even when they’re hungry. Jonathan Deutsch, PhD, director of Drexel University’s Center for Hospitality and Sport Management, explains in a press release how FSSM addresses this: “For example, we took those brown bananas, peeled them, froze them and food processed them to create banana ice cream, which is much more appealing.” Drexel has given facelifts to similarly lackluster items, like canned peas. This requires chefs to think in a new, more sustainable way: Instead of concocting a recipe and then buying ingredients, they must be creative with what’s given to them.

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Ask Stanford Med, Health and Fitness, Nutrition, Obesity, Precision health, Stanford News

A Stanford physician takes a precision health approach to living a healthier lifestyle

A Stanford physician takes a precision health approach to living a healthier lifestyle

timthumbNearly 70 percent of Americans ages 20 or older are overweight or obese, including Larry Chu, MD, a Stanford anesthesiologist and executive director of Medicine X.

Chu, who has struggled with his weight for over a decade, knew he was overweight but didn’t think it was a serious threat to his health. This changed during a routine doctor’s visit. As he explains in a podcast, Chu was shocked to learn that lab results showed he was at high risk for stroke and heart attack. He decided to take action and launch precision:me, a personal blog project chronicling the first 90 days of his journey to live a healthier lifestyle.

Why most of us try to slim down by shunning carbs, stepping up our exercise routines and secretly weighing ourselves each morning, Chu is tracking his health data using a range of gadgets and other tools and sharing the every detail of his progress publicly on his blog. He is also posting photos and podcasts.

Below Chu discusses why he choose to take this unique approach to achieve his weight-loss goals, how he hopes it will inform the broader conversation about obesity and its potential to demonstrate the value of digital tools in enhancing personal health.

What was the catalyst for precision:me?

One of the misconceptions about obesity is that it is a lifestyle disease and if people would only eat less and move more they would be fit. In my case, this is a health journey I have been struggling with since my residency training at Stanford. Using precision health tools to address obesity is a new approach that we are focusing on in precision:me. Stanford has recently announced exciting plans for precision health. I thought it was a good time to share how we at Medicine X see precision health as a novel approach that individuals and their providers can use today to tailor precise and individualized care. It is a very practical and personal dive into developing and implementing a precise plan to modify my diet and metabolic profile to forestall the development of more significant chronic diseases, such as diabetes and heart disease, using data and analytics provided through digital health tools and expert medical, nutritional and fitness collaborators.

Why did you decide to make all of your health data available online for public consumption?

It was an easy and difficult decision at the same time. There is incredible stigma associated with obesity, which we discuss on the precision:me website. Being overweight or obese is a subject that many of us find difficult to talk about. Sharing information can make it easier to start a dialogue. Advances in precision health at Stanford and around the world will depend upon patients sharing their personal health data in a secure and protected fashion with researchers. By sharing my data with the public, I hope to help everyone see what it is like to live with obesity as a condition, break down misconceptions and misperceptions about the disease, and help shine a light on the value of sharing data to help others.

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Autism, Behavioral Science, Medical Apps, Nutrition, Stanford News, Technology

Stanford grad students design new tools for learning about nutrition, feelings

Stanford grad students design new tools for learning about nutrition, feelings

2789442655_1f5c33ac51_zMushrooms and tomatoes, veggies that are often reviled by preschoolers, star in a new app designed by a Stanford graduate student that aims to involve children in preparing, and eating, healthy meals.

“Children are more likely to try food that they’ve helped cook,” explained Ashley Moulton, a graduate student in the School of Education’s Learning, Design and Technology Program, in a recent Stanford News story.

Moulton’s iPad app, Nomster Chef, is one of several student projects featured in the article and accompanying video:

Before cooking, children receive an educational video about a food they’ll be working with – for example, a video on how mushrooms grow. The app also incorporates food information in the recipe steps, like the fact that tomatoes are actually a fruit.

After user-testing the app prototype, “I heard from parents that they noticed differences in how their kids are eating,” Moulton said. The app also kept kids engaged throughout the cooking process.

For her project, fellow student Karen Wang developed an iPad app called FeelingTalk that helps children with autism interpret facial expressions:

…[I]n the first level of FeelingTalk, kids choose the one face that’s different (a sad face) from the three happy faces on the screen. The app will then label the different face “sad.”

“My app will be utilizing learning mechanics that directly work with the autistic brain to help them work on something that they’re having difficulty with,” Wang said. “By leveraging something they’re good at, we’re going to teach them to get comfortable looking at people’s faces, examining the key features, and eventually understanding emotions.”

Moulton, Wang and other students will present their work this afternoon at the LDT Expo at the Stanford Graduate School of Education.

Previously: A look at the MyHeart Counts app and the potential of mobile technologies to improve human health and No bribery necessary: Children eat more vegetables when they understand how food affects their bodies
Photo by Peter Weemeeuw

Health and Fitness, Nutrition, Obesity, Research

Can food mentions in newspapers predict national obesity rates?

Can food mentions in newspapers predict national obesity rates?

New_York_TimesFood words trending in today’s newspapers could help predict a country’s obesity rates in three years, according to findings recently published in the journal BMC Public Health. 

In the study, researchers examined whether media mentions of food predate obesity prevalence by analyzing mentions of foods in New York Times and London Times articles over the past 50 years. Using this data, they statistically correlated it with each country’s annual Body Mass Index, or BMI. Brennan Davis, PhD, lead author of the study and an associate professor of marketing at California Polytechnic State University, said in a release that results showed:

The more sweet snacks are mentioned and the fewer fruits and vegetables that are mentioned in your newspaper, the fatter your country’s population is going to be in 3 years, according to trends we found from the past fifty years … But the less often they’re mentioned and the more vegetables are mentioned, the skinnier the public will be.

Researchers say the research could help public health officials better understand the effectiveness of current obesity interventions.

Previously: Adventurous eaters more likely to be healthy, new study shows, Want kids to eat their veggies? Researchers suggest labeling foods with snazzy names, Can edible “stop signs” revive portion control and curb overeating? and Can dish color influence how much you eat?
Photo by Jaysin Trevino

Immunology, Nutrition, Stanford News, Videos

A Stanford dietician talks food sensitivities

A Stanford dietician talks food sensitivities

Ever wondered what the difference between a food allergy and a food sensitivity is? Neha Shah, MPH, RD, CNSC, a registered dietician at the Stanford Digestive Health Center, sheds some light in a new video.

In people with food allergies, she explains, the immune system responds to the presence of the food, which isn’t the case for food sensitivities. People with food allergies have to avoid the culprit foods entirely, whereas people with food sensitivities can sometimes have small amounts of the food – though they must figure out what their threshold is. (Too much and the offending food might set off other symptoms like gas, bloating or diarrhea.) Shah uses lactose intolerance as an example of a very common food sensitivity and describes how people can understand their threshold.

Previously: Peanut products and babies: Now okay?, Stanford dietitian explains how – not just what – you eat matters, Taking a bite out of food allergies: Stanford doctors exploring new way to help sufferers, Eating nuts during pregnancy may protect baby from nut allergies and Ask Stanford Med: Pediatric immunologist answers your questions about food allergy research

Behavioral Science, Nutrition, Research, Women's Health

Adventurous eaters more likely to be healthy, new study shows

Adventurous eaters more likely to be healthy, new study shows

9044506418_142bb67dcc_zAre you willing to sample chocolate-covered silkworm pupae? What about blood sausage or, for the vegetarians among us, some shoo-fly pie (one of my personal favorites)?

If any or all of those sound tasty, or at least worth trying, then you’re probably a food neophile, aka an adventurous eater. And for you, I’m the bearer of good news: Adventurous eaters have lower body-mass indexes and are generally more conscious about healthy eating than their less adventurous diners, according to a study published recently in Obesity.

Researchers from Cornell University and the University of Vermont recruited about 500 women and had them complete a survey on their eating habits and willingness to try new things and foods. The answers shed insight into the connections between healthy habits and adventurousness:

…Adventurous eaters were less concerned that a food was easy to prepare and about its price, but more interested in cooking as a way to connect with their heritage and more likely to have friends over for dinner. Given that cooking at home is associated with lower BMI and increased consumption of healthy foods, if adventurous eaters are comfortable with foods that were harder to prepare, and often have friends over for dinner, it may be that they prepare their own food more often than non-adventurous eaters. Furthermore, eating with others versus eating alone has been associated with decreased intake in some studies. The lower concern about price of foods exhibited by more adventurous eaters is in line with characteristics of foodies, who are much more concerned with food quality than food price. Because healthy foods are often more expensive than junk foods and require preparation, adventurous eaters may be more likely to procure and prepare these types of foods than non-adventurous eaters.

The authors go on to write that the findings “have exciting practical implications” and suggest “several strategies [that] practitioners could use to help increase adventurousness.” But they acknowledge the research has several limitations, including its lack of men and definition of “adventurousness.”

Previously:  Where is the love? A discussion of nutrition, health and repairing our relationship with food, “They might be healthier, but they’ll still be junk foods”: Expert comments on trans-fat ban and Examining how food texture impacts perceived calorie content
Photo by Smabs Sputzer

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