Published by
Stanford Medicine



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

FDA, Health and Fitness, In the News, Nutrition, Public Health

“They might be slightly healthier, but they’ll still be junk foods”: Expert comments on trans-fat ban

"They might be slightly healthier, but they'll still be junk foods": Expert comments on trans-fat ban

4345026096_35defbf6b0_zAs you’ve probably heard, the FDA ruled last week to ban trans-fats and phase them out of all food products over the next three years. This news has been widely covered, both heralded for its health implications and critiqued for being too long in coming. Yet either way, it is not a panacea, as Stanford Medicine professor Christopher Gardner, PhD, explained when he shared his opinion with me over the weekend:

The true impact of the FDA ban on trans-fats will not be known until we find out what substitutes the food industry finds, and what that does to the sale of junk food and the health of Americans in response to the switch. It could be beneficial. But it isn’t as if trans-fats will be gone and everyone will eat an extra two servings of vegetables in their place.

Gardner, who has spent the past 20 years researching the health benefits of various nutrition components, pointed out that “a lot of good people and excellent scientists worked on this for a long time” and “it took a great deal of effort to assemble the science to demonstrate that this is something so harmful in the American diet that it should be removed with an FDA ban.” He also offered more specifics on what food companies might do following the ban:

The companies making those products are unlikely to remove those junk food products entirely from the shelves of grocery stores across America. Instead, it is most likely that they will look for an alternate form of fat that will serve as closely as possible the same role that trans-fats served. Trans-fats act like saturated fats in terms of being solid rather than liquid at room temperature. This can help the icing on a cupcake stay solid, and it can give a “mouth feel” of solid fat that people like to taste in their food. The goal of the food industry will be to replace the trans-fat with another fat that is solid at room temperature, which likely means the replacement could very well be as bad as the trans fats themselves.

For example, palm oil or esterified stearic acid are likely to be options. For the palm oil, this will mean destruction of rain forests and biological diversity. For esterified stearic acid, this will mean another reason to grow more monocultures of soybeans from which to extract the oil. Both of these will likely have a negative environmental impact. There are likely other choices to consider.

After all this, will those junk foods now be health foods? Absolutely not. They might be slightly healthier junk foods, but still junk foods.

Previously: Want to curb junk food cravings? Get more sleep, Talking to kids about junk food ads, and Trans-fat still lurks in packaged foods
Photo by Kevin

Global Health, Nutrition, Pediatrics, Stanford News, Technology, Women's Health

Stanford initiative aims to simultaneously improve education and maternal-child health in South Africa

Stanford initiative aims to simultaneously improve education and maternal-child health in South Africa

Nomfusi_counselingWhat if we could “leapfrog” over the education and technology gap in low-resource countries, while at the same time improving maternal and early childhood health in those areas? That is precisely the promise of a new Stanford-sponsored initiative spearheaded by Maya Adam, MD, a lecturer in the human biology program here.

I recently had the chance to speak on the phone with Adam and hear more about this project, which consists of designing picture-based educational videos that are loaded on tablets and distributed among community-health workers. At present, the video on child nutrition is being used as a pilot in South Africa through the organization Philani, where twelve “mentor mothers” have been using the tablets since March. As you’ll read below, there is immense potential for the project to scale up in the near future.

What have the results of this initiative been so far?

The feedback that we’ve gotten was that a lot of the mothers being counseled said, “You know, you’ve been using phrases like ‘balanced diet’ for many years, and I didn’t quite know what that meant until I saw the plate with the green vegetables and the little bit of protein and the little bit of grains.” Certain phrases became clearer when they were drawn in pictures. Also, we found a lot of the children wanted to come watch because it was a screen-based activity.

The workers themselves found it useful to convince their patients, for example, of the importance of prenatal care, because when the patients heard it both from the video and from them, it was almost as if the video was validating their messaging. So they’re very eager to have the project continue. They have a whole list of other videos they want us to make, from breastfeeding to HIV/AIDS prevention… It’s really been a powerful way both to teach and give these highly intelligent women access to technology that could enhance their education and help them overcome the barriers in their lives.

How easy would it be to use these videos in different regions of the world? 

slider-9_compressedWe have videos translated into English, Xhosa, and now Spanish, because they’ll be used next in Guatemala… We can use English in the U.S. in under-resourced locations. These are all very universal messages, and that’s why it’s so exciting: For a relatively small amount of effort, we can make videos that can be both translated into many other languages, and subtly altered visually so they resemble women and children in each different part of the world. For example, while we were creating the video, we put the braids that African women traditionally wear in their hair on a different layer of the Photoshop, so that layer can be removed and the resulting woman will have straight dark hair that would be more appropriate for use, say, in Guatemala.

We thought a lot about how to represent food. A real plate of food from South Africa would be culturally inappropriate in Guatemala, but by using cartoon images of fruits and vegetables, it becomes much more universal… We tried to show a variety of different fruits and vegetables without specifically showing that “this is a guava,” because a guava might not grow in other parts of the world.

Continue Reading »

Medical Education, Mental Health, Nutrition, Stanford News, Surgery

Keeping an even keel: Stanford surgery residents learn to balance work and life

Keeping an even keel: Stanford surgery residents learn to balance work and life

med students in sailboat

Residency is one of the most intense times in a surgeon’s training, and it can take a toll physically and mentally on newly minted medical school graduates as they learn to cope.

To help them counter that stress, Stanford’s Department of Surgery started the Balance in Life Program for its residents. The program, and one of its team-building exercises – a sailing lesson in one of the world’s best sailing spots, the San Francisco Bay – were highlighted in a recent Inside Stanford Medicine story.

As described in the piece, the program is dedicated to the memory of Greg Feldman, MD, a former chief surgical resident at Stanford who committed suicide in 2010. The program provides basics like easy-to-access healthy meals, group therapy sessions and social activities, and Ralph Greco, MD, the program’s director said of it:

A lot of people would argue with the notion that such a program is necessary… I know our day of sailing may raise some eyebrows, but our faculty decided that we should do whatever we could to give these young people the tools they need to help them deal with the vicissitudes of life and medicine through the rest of their careers.

The article also notes that the program attracts residents interested in work-life balance to Stanford:

“The fact that we have this Balance in Life Program is great for recruitment of like-minded individuals,” [resident Micaela Esquivel, MD,] said. “I can tell medical students considering us that they would be hard-pressed to find another program that cares enough about their well-being to offer what we do.”

Previously: A call to action to improve balance and reduce stress in the lives of resident physicians, Surgeon offers his perspective on balancing life and work, Program for residents reflects “massive change” in surgeon mentality and New surgeons take time out for mental health
Photo by Norbert von der Groeben

FDA, In the News, Nutrition, Public Health

FDA changes regulation for antibiotic use in animals

FDA changes regulation for antibiotic use in animals

8756885685_0ebc1c75ce_zLivestock can no longer be fed antibiotics “preventatively” or to help them grow bigger. The FDA has ruled to change their regulations of how drugs can be administered to food animals, including those used to make animal feed.

After this ruling, livestock producers can only use antibiotics to treat animals that actually have an infection, and only under the supervision of a veterinarian. These new rules are aimed at decreasing the risk of developing drug-resistant bacteria, sometimes called “super bugs.” According to the Centers for Disease Control and Prevention, drug-resistant bacteria cause 2 million illnesses and about 23,000 deaths in the United States each year.

According to an article from The Hill, the Department of Health and Human Services is moving forward with new regulations for hospitals, and President Obama has called on government cafeterias to prioritize meat that has been raised with responsible antibiotic practices.

Previously: Paradox: Antibiotics may increase contagion among salmonella-infected animals, and Healthy gut bacteria help chicken producers avoid antibiotics
Photo by Chiot’s Run

Emergency Medicine, Nutrition, Pediatrics, Rural Health

Study finds arm circumference is accurate measure of malnutrition in children with diarrheal illnesses

Study finds arm circumference is accurate measure of malnutrition in children with diarrheal illnesses

Malnutrition is a leading cause of mortality in children under the age of five, contributing to approximately 3.5 million child deaths worldwide each year. Currently, the World Health Organization and Doctors Without Borders recommend using calculations based on the patient’s body weight or arm circumference to assess their nutritional status. But, it’s not known if they are reliable measures of malnutrition in children that suffer from diarrhea and dehydration — two symptoms that can affect body weight and are common in undernourished kids.

Now, a study (subscription required) published this month in the Journal of Nutrition shows that mid-upper arm circumference can accurately assess malnutrition in children with diarrhea and dehydration and it’s better at assessing malnutrition than weight-based measures.

In the study, Rhode Island Hospital emergency medicine physician Adam Levine, MD, and his team analyzed 721 records of children (under the age of five) who were examined at an urban hospital in Dhaka, Bangladesh for acute diarrhea. They found that measurements based on a child’s mid-upper arm circumference accurately diagnosed malnutrition, but measurements based on weight were unreliable and misdiagnosed about 12-14 percent of the cases when the patient had diarrhea and dehydration.

“Because dehydration lowers a child’s weight, using weight-based assessments in children presenting with diarrhea may be misleading,” Levine said in a press release. “When children are rehydrated and returned to a stable, pre-illness weight, they may still suffer from severe acute malnutrition.”

Since poor nutrition is a common problem in areas where medical resources are limited, the best tools to diagnose malnutrition are effective and inexpensive. Tape measures are cheaper and are often easier to come by than scales, so the results of this study are especially encouraging for people who want the best and most affordable way to measure malnutrition in children. “Based on our results, clinicians and community health workers can confidently use the mid-upper arm measurement to guide nutritional supplementation for children with diarrhea,” said Levine.

Previously: Stanford physician Sanjay Basu on using data to prevent chronic disease in the developing worldMalnourished children have young guts and Seeking solutions to childhood anemia in China
Photo by European Commission DG ECHO

Events, Health and Fitness, Nutrition, Obesity, Stanford News, Women's Health

Women’s health expert: When it comes to prevention, diet and exercise are key

Women's health expert: When it comes to prevention, diet and exercise are key

16262076932_96f8309b43_zThis Monday was the sixth annual Stanford Women’s Health Forum, hosted by Stanford’s Women and Sex Differences in Medicine center (WSDM), and I was happy to have been present for the lively talks. The forum focused on prevention, and the keynote, delivered by Marcia Stefanick, PhD, professor of obstetrics and gynecology and WSDM director, highlighted physical activity and weight management as the key preventative actions for women to take.

High blood pressure remains the number one preventable cause of death in women, with physical inactivity and high BMI, both of which contribute to high blood pressure, in third and fourth place. (For the curious readers, smoking comes in second.) Because prevention requires changes in behavior, behavior was what Stefanick focused on. Rather than reinforcing many women’s feelings of embarrassment about their weight, she said, providers should help women feel that they can do something about it.

Healthier behaviors must include diet and exercise. Both fatness and low fitness cause higher mortality; realistic expectations about how to change both should factor into care. Stefanick emphasized that weight loss should be slow: 10 percent of one’s body weight baseline over six months, or one pound per week for moderately overweight people, and no more than two pounds per week. And we need to stop being so sedentary, Stefanick exclaimed. The classic principles of exercise apply – gradually increase the frequency, intensity, and/or duration of exertion. Adults should be getting at least two and a half hours of moderate-intensity aerobic physical activity per week, in addition to doing muscle-strengthening activities at least twice a week, the conference flyer read.

However, citing the problems of eating disorders and older women losing weight without trying, Stefanick stressed that “weight management is a spectrum; there are extremes at both ends.” In describing variations on mesomorphic, endomorphic, and ectomorphic body types, she stated that “we don’t know what the optimal body type is.” It probably varies for each person.

Something I found particularly interesting was Stefanick’s description of gynoid vs android fat distribution patterns (which I learned as “pear” and “apple” body shapes, respectively). Gynoid distribution around the hips, thighs, and butt is more common in women, and includes more subcutaneous fat, while in android distribution, which is more common in men, fat collects around the belly and chest and is actually dispersed among the organs. Such intra-abdominal fat is more damaging to health, as it affects the liver and lipid profile and can cause heart disease, but it’s also much easier to get rid of through exercise (which is one reason men overall have less trouble losing weight than women).

In the spirit of more personalized care, Stefanick also discussed how recommended weight changes during pregnancy should vary according to the person’s prenatal BMI. Someone underweight could gain up to 40 pounds and be healthy, she pointed out, while obese people might actually lose weight during pregnancy for optimal mother-baby health.

Previously: Why it’s critical to study the impact of gender differences on diseases and treatmentsWhen it comes to weight loss, maintaining a diet is more important than diet typeApple- or pear-shaped: Which is better for cancer prevention?A call to advance research on women’s health issues and To meet weight loss goals, start exercise and healthy eating programs at the same time
Photo by Mikaku

Autoimmune Disease, Cancer, Infectious Disease, Microbiology, Nutrition, Stanford News

Getting to the good gut: how to go about it

Getting to the good gut: how to go about it

In a blog post a few years ago I wrote, The Good Gutwith misplaced parenthetical self-assuredness:

Anybody who’s ever picked up an M&M off the sidewalk and popped it into his or her mouth (and, really, who among us hasn’t?) will be gratified to learn that the more germs you’re exposed to, the less likely you are to get asthma … hay fever and eczema.

I soon learned to my surprise, if not necessarily to my embarrassment, that virtually nobody – at least nobody over 6 – cops to having stooped-and-scooped as I routinely did as a kid on what I called my “lucky-sidewalk” days.

But those M&Ms may have been the best pills I ever took.

Stanford microbiologists Justin Sonnenburg, PhD, and Erica Sonnenburg, PhD, (they’re married) have written a new book, The Good Gut, about the importance of restocking our germ-depleted lower intestines.

Massive improvements in public sanitation and personal hygiene, the discovery of antibiotics and the advent of sedentary lifestyles have taken a toll on the number and diversity of microbes that wind up inhabiting our gut. According to The Good Gut, we need more, and more varieties, of them. And we need to treat them better. The dearth of friendly microorganisms in the contemporary colon is due not just to a lack of bug intake but to a lack of fiber in the modern Western diet. Indigestible to us, roughage is the food microbes feast on.

The Good Gut packages that message for non-scientists. “We wanted to convey the exciting findings in our field to the general public,” Justin Sonnenberg recently told me. “We’d noticed we were living our life differently due to our new understanding. We were eating differently and had modified both our own lifestyle and the way we were raising our children.”

In simple language, the Sonnenburgs explain how the pieces of our intestinal ecosystem fit together, what can go wrong (obesity, cancer, autoimmunity, allergy, depression and more), and how we may be able to improve our health by modifying our inner microbial profiles. Their book includes everything from theories to recipes, along with some frank discussion of digestive processes and a slew of anecdotes capturing their family’s knowledge-altered lifestyle.

Continue Reading »

Evolution, Global Health, In the News, Microbiology, Nutrition, Research

A key bacteria from hunter gatherers’ guts is missing in industrial societies, study shows

392924423_860dafa0a4_oTrends like the paleo diet and probiotic supplements attest to the popular idea that in industrial societies, our digestion has taken a turn for the worse. The scientific community is gathering evidence on how the overuse of antibiotics affects our microbiome, and on what might be causing the increasing incidence gastrointestinal inflammatory disorders like Crohn’s disease and colitis. Scientists are now one step closer to knowing exactly what has changed since the majority of humans were hunter-gatherers.

Yesterday, a paper published in Nature Communications found that an entire genus of bacteria has gone missing from industrialized guts. Treponema are common in all hunter-gatherer societies that have been studied, as well as in non-human primates and other mammals. Treponema have primarily been known as pathogens responsible for diseases like syphilis, but the numerous strains found in the study are non-pathenogenic and closely resemble carbohydrate-digesting bacteria in pigs, whose digestive system is notably similar to that of humans. The genus is undetectable in humans from urban-industrial societies.

The study, led by anthropologists from the University of Oklahoma and the Universidad Científica del Sur in Peru, used genomic reconstruction to compare microbes in stool samples from two groups in Peru, one of hunter-gatherers and one of traditional farmers, with samples from people in Oklahoma. Each group comprised around 25 people. This is the first comprehensive study of the full-spectrum of microbial diversity in the guts of a group of hunter-gatherers – in this case, the Amazonian Matses people.

The researchers also sought to understand how diet affects gut health: The hunter-gatherers ate game and wild tubers, the traditional farmers ate potatoes and domestic mammals, and the Oklahomans ate primarily processed, canned, and pre-packaged food, with some additional meat and cheese.

Science published a news report discussing the findings, in which co-author Christina Warinner, PhD, an anthropologist at the University of Oklahoma, is quoted as saying:

Suddenly a picture is emerging that Treponema was part of core ancestral biome. What’s really striking is it is absolutely absent, not detectable in industrialized human populations… What’s starting to come into focus is that having a diverse gut microbiome is critical to maintaining versatility and resiliency in the gut. Once you start to lose the diversity, it may be a risk factor of inflammation and other problems.

Further research is needed to answer the next question: Is there a direct link between the absence of Treponema and the digestive health and prevalence of certain diseases (like colitis and Crohn’s) in industrialized humans? If so, this could be a valuable key to increasing our digestive health. It would also indicate that imitating a paleo diet is not enough to achieve a real “paleo gut.”

Previously: Drugs for bugs: industry seeks small molecules to target, tweak, and tune-up our gut microbes, Tiny hitchhikers, big impact: studying the microbiome to learn about disease, Civilization and its dietary (dis)contents: Do modern diets starve our gut-microbial community?, Stanford team awarded NIH Human Microbiome Project grant, and Contemplating how our human microbiome influences personal health
Photo by AJC1

Stanford Medicine Resources: