Busting myths about milk

Photo by artemtation

Milk used to be simple. Your local dairy, say Berkeley Farms, delivered it to your doorstep.

But now we are faced with an unfathomable array: nonfat, low-fat or whole milk? Almond, soy, rice, hemp or oat milk? From goats or cows? With or without lactase? Raw or pasteurized? Plain or flavored? There’s even an ongoing controversy over which of these drinks can be called milk.

To sort through the confusion, I spoke with Stanford nutrition scientist Christopher Gardner, PhD. He is working to clear up some of the biggest misconceptions we have about milk.

Most of us grew up believing that milk is important for children to build strong bones and for the elderly to prevent osteoporosis. But milk, a good source of calcium, isn’t necessarily the most critical factor for bone health, Gardner said.

“There are countries like Japan and India where the population is predominantly lactose intolerant, where milk intake is low and hip fracture rates are also low. But many of those cultures do more weight-bearing activities than Americans,” he said. “It’s better to be physically active than drink milk as a way to strengthen your bones.”

Studies have shown that drinking milk can improve your bone density, but whether it helps prevent bone fractures is debatable, he added.

But don’t young kids need milk? According to Gardner, it depends on what kind of milk. Breast milk is incredibly important, but cow’s milk isn’t, he said.

“This myth goes way back to before the food pyramid when the National Dairy Council offered to provide nutrition material to schools for free. And in all those materials, they said that you need multiple servings of dairy every day for a healthy diet,” Gardner said. “That was never agreed on. A lot of people are lactose intolerant, and you don’t need it.”

Milk can be healthier than other options like soda. He recommended checking the nutrition panel to make sure the milk isn’t just as sugary as soda though, particularly with plant-based milks. “The popular vanilla and chocolate versions of the plant-based milks are often loaded with added sugar. Even the plain is typically sweetened, but you can get unsweetened. The lactose in milk isn’t so bad so there is no need to water it down, just avoid milks with added sugars.”

The nutrition label also allows you to compare the amount of fats, protein, carbs and vitamins in each type of milk. “For example, the plant-based milks generally don’t have saturated fat like cow’s milk so they don’t raise LDL-cholesterol as much as dairy milk, but they do have about the same amount of calcium,” he said. “And soy milk has the same amount of protein as dairy milk, but almond milk has much less protein.”

Another common misunderstanding is that 2 percent milk means that two percent of the calories are from fat — it’s really 2 percent of the weight (which is mostly water) and 35 percent of the calories, he said. “Whole milk has close to 50 percent of its calories as fat, and 1 percent milk has about 20 percent.”

However, your milk’s fat content may not affect your weight. The old belief was that drinking whole fat milk will make you fat and skim milk will help you lose weight. But this was refuted by Harvard’s Nurses’ Health Study that followed the diets of over 100,000 nurses for over 30 years, including how their diets changed.

“The Harvard study found that switching back and forth from whole fat to 2 percent to 1 percent was not associated with changes in weight,” explained Gardner.

But does drinking more milk help? Some small, short-term studies showed that people lost weight if they drank more milk. According to Gardner, this raises the always present nutrition research challenge: Was it drinking more milk or was it consuming less of something else that caused the weight loss?

And what about raw milk? Raw milk proponents argue that pasteurization kills off important healthy bacteria along with the bad listeria bacteria, but Gardner says that it’s difficult to prove any health benefits from these bacteria. Some raw milk producers also claim that it is easier to digest. However, Gardner’s study found that lactose intolerant participants had the same symptoms with raw and pasteurized milk.

And what does Gardner himself drink? He said he gave up cow’s milk for ethical reasons.

“Now, I drink unsweetened soy milk,” he admitted. ‘In our household, my wife doesn’t digest dairy milk very well, so we don’t even have it around. My four boys all drink unsweetened soy milk.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

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New study intervenes to help female collegiate distance runners eat enough

Photo by David Gonzalez

Like other athletes at risk, female collegiate distance runners are predisposed to develop bone stress injuries from a condition known as the female athlete triad triad, said Michael Fredericson, MD, a professor of orthopaedic surgery and sports medicine at Stanford, who has worked with Stanford athletes for more than 25 years.

The triad stems from an energy deficiency, he explained:

“When your body isn’t getting enough food, then you stop producing normal levels of sex hormones, which leads to menstrual dysfunction. Your growth hormones go down, so you lose muscle mass. Your thyroid hormones go down, so your metabolism gets suppressed. And your stress hormones go up, which also leads to menstrual dysfunction and reduced muscle mass. And all of that leads to lower bone density, and eventually osteopenia [low bone strength] or even osteoporosis.”

The problem is common. “Based on our historical data, 38 percent of our female runners developed stress fractures over a three-year period from 2010-2013,” Fredericson said. “I knew the time had come to do something to prevent this.”

He is investigating the effectiveness of a nutritional intervention, in collaboration with Aurelia Nattiv, MD, from the University of California, Los Angeles. They have enrolled about 180 male and female runners from Stanford and UCLA in their study.

“The goal is to have our runners eat 45 kcal/kg/fat free mass per day, which is really just a normal diet — so their energy input equals their energy output,” Fredericson said. “We found a third of the women were getting less than this and half of the men were getting less. So it’s fair to say that a significant number of our runners were not getting adequate nutrition or calories.”

The runners met individually with a sports dietician and filled out an extensive dietary questionnaire to estimate their food intake, Fredericson told me. A low-dose x-ray machine was also used to measure their bone density and basic blood work measured vitamin D and thyroid levels, he said. Finally, their risk of female athlete triad was assessed using an established point system.

After their health assessment, a dietician helped each runner select individual nutrition goals, like adding a snack or increasing the energy density of a current meal, Fredericson said. “We typically want them to eat smaller more frequent meals — particularly right before and immediately after exercising,” he said.

The runners also used an app developed by collaborators at UCLA, which provided an eight-week nutrition education curriculum, including handouts, video clips, recipes and behavior modifying exercises.

Although the researchers have only completed the first year of a three-year study, they have found their intervention is working. “A majority of the runners have increased their bone density over the one year period by 2 to 5 percent,” Fredericson said. “ Our preliminary findings also show for every one-point increase in risk score, there was a 17 percent increase in the time it took to recover after an injury. … Anecdotally, we are seeing less injuries and the type of injuries that we are seeing are less severe.”

He emphasized the importance of the work:

“We have a number of young women that are exercising at levels beyond their ability to support their nutritional requirements. By the time they enter college many of them have osteoporosis … Ours is the first attempt to address these issues in an organized study with elite athletes. We need to turn things around for these young women, and prevent more serious health problems later in life.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Socioeconomic status and food: A Stanford researcher observed families to learn more

Photo courtesy of Priya Fielding-Singh

Priya Fielding-Singh, a PhD candidate in sociology at Stanford, wanted to learn more about the relationship between socioeconomic status and diet. So she made observations and conducted in-depth interviews with parents and adolescents from 73 families across the socioeconomic spectrum throughout the San Francisco Bay Area. I recently spoke with her to learn about her study.

What inspired you to research the relationship between socioeconomic status and diet?

“Growing up, my family was a foster family and we took in many children that came from impoverished backgrounds. I think this early exposure to social inequality was formative in shaping my interests and propelling me into the field of sociology. I became interested in food the more that I learned about diet and disease prevention.

We have excellent large-scale, quantitative studies that show a socioeconomic gradient in diet quality in the United States. Thus, we know that socioeconomic status is one of a few key determinants of what and how people eat. But what we understand less well is why. I wanted to know: how do people’s socioeconomic conditions shape the way that they think about and consume food?”

How did you obtain your data?

“In almost every family, I interviewed, separately, at least one parent and one adolescent to better understand both family members’ perspectives. I also conducted 100 hours of observations with families across socioeconomic status, where I spent months with each family and went about daily life with them.

I saw very clearly that food choices are shaped by myriad different external and internal influences that I only gained exposure to when I spent hours with families on trips to supermarkets, birthday parties, church services, nail salons and back-to-school nights. Importantly, I was able to collect data on family members’ exchanges around food, including discussions and arguments. What families eat is often the product of negotiations and compromises.”

What was it like to observe the family dynamics first-hand?

 “I’m a very curious person, as well as a people person, so I felt in my element conducting ethnographic observations. I was touched by how generously families welcomed me into their lives and shared their experiences with me. Because families were so open with me — and in many cases, did not attempt to shelter me from the challenging aspects of family life — observations were an incredibly illuminative part of the research.”

Based on your study, how is diet transmitted from parents to children?

“I found that parents play a central role in shaping teenagers’ beliefs around food, but there was often a difference in how adolescents perceived their mothers and fathers in relation to diet. Adolescents generally saw their mothers as the healthy parent and their fathers as less invested in healthy eating. So, feeding families and monitoring the dietary health of families largely remains moms’ job, as I explained in a recent article.

In addition, I found that how mothers talked to adolescents about food varied across socioeconomic status. My Stanford colleague, Jennifer Wang, and I wrote a paper explaining these differences. More affluent families had discussions that highlighted the importance of consuming high quality food, which may strengthen messages about healthy eating. In contrast, less privileged families had more discussions about the price of food that highlighted the unaffordability of healthy eating.

Finally, I found that lower-income parents sometimes used food to buffer their children against the hardships of life in poverty. They often had to deny their children’s requests for bigger purchases because those purchases were out of financial reach, but they had enough money to say yes to their kids’ food requests. So low-income parents used food to nourish their children physically, but they also used food to nourish their children emotionally.”

What were your favorite foods as a child?

“My favorite food growing up is the same as my favorite food today: ice cream. Beyond that, the diet I ate as a child was very different than the one I follow now. I grew up in a family of carnivores, but I became a vegetarian in my early 20s and never looked back.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Reimagining Nutrition Education: Doctor-chefs teach Stanford medical students how to cook

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Photograph courtesy of Michelle Hausman

Stanford medical students still learn traditional topics like anatomy, genetics and neuroscience. But now, they can also learn how to cook, thanks to a new hands-on course developed in part by Stanford’s Michelle Hauser, MD.

A former Le Cordon Bleu chef, Hauser is currently an internal medicine-primary care attending for Stanford residents and a postdoctoral research fellow at the Stanford Prevention Research Center. She teamed up with Stanford pediatrics instructor Maya Adam, MD; physician Tracy Rydel, MD; nutrition researcher Christopher Gardner, PhD; physician-chef Julia Nordgren, MD; and Stanford chef, David Iott, to launch the new class, which is featured in a video.

Hauser said the course aims to teach future clinicians how to cook healthy food, so they can more effectively counsel their patients on nutrition and diet. Intrigued, I spoke with her recently.

Why did you introduce this course?

“Diet is the most significant risk factor for disability and premature death in the US. However, less than one-third of medical school and residency programs offer a dedicated nutrition course to their students. When courses are available, many schools use outdated, overly long and complicated online modules rather than in-person nutrition instruction. They often just focus on nutrients, whereas patients think of nutrition in terms of food. And most schools don’t teach how to effectively counsel patients to change their behavior around eating — people know it is healthy to eat more vegetables, but how do they accomplish this? We need to better prepare physicians to treat the underlying causes of disease and to prevent diet and lifestyle-related diseases from occurring in the first place.”

How can your course help?

“Teaching kitchens are the perfect, hands-on medium to help doctors learn about food. By learning to prepare delicious, healthy food for ourselves, we become healthier — and studies show that physicians with healthy habits are more likely to counsel patients on those habits. Additionally, it’s more fun and memorable to learn about food and nutrition while cooking and sharing meals together than it is to sit in a lecture hall.

As a platform to teach about nutrition, our new teaching kitchen elective focuses on how to prepare healthy meals based on plants and whole foods, a diet that is ideal for the majority of the population. We also teach a concept called the “protein flip” — instead of having the center of your plate be a large piece of meat, you use meat as a garnish for a plate full of plant-based foods, such as vegetables, fruits, whole grains, legumes, nuts and seeds. Think veggie chicken stir-fry with brown rice or a main course salad with a small portion of grilled salmon.

Our sessions use a flipped classroom format. Before class, students view engaging preparatory videos online (and many of these are available through Stanford’s Food and Health series). At Stanford’s teaching kitchen, they watch the chefs’ cooking demonstrations and then lace up their aprons and start chopping and cooking. In addition, Tracy Rydel, Maya Adam, Christopher Gardner and faculty from other medical programs are cooking alongside the medical students to represent the lay cook’s perspective, as well as spread the idea of using teaching kitchens to others in the Bay Area and beyond. At the end of each session, we all share and eat together.”

How do you make healthy food appealing?

“Healthy food has gotten a bad rap for far too long. We need to make sure that healthy food is delicious if we expect people — including ourselves — to eat it so that it can nourish our bodies and prevent nutrition-related chronic diseases. Food is a huge part of all of our cultural identities and is intricately linked with many of our fondest memories. I often see medical professionals in training and in practice tell patients to stop eating a whole variety of things — many with personal and cultural significance — without helping them figure out what and how to eat differently. And these conversations often make it sound like the patient needs a ‘special’ diet inappropriate for the whole family. Instead, we need to celebrate the togetherness of sharing healthy food.

 For the final project, the students will make favorite healthy foods that mean something to them. For instance, I would make hummus, tabouli and falafel wraps (falafels rolled up in warm whole-wheat pita bread with chopped tomatoes, scallions, cucumbers and spring mix drizzled with lemon-tahini sauce). As a vegetarian with a dairy allergy, my Irish-immigrant family’s traditional Christmas dinner normally left me with a lonely potato and a few token veggies. However, a few years back I cooked this Middle Eastern meal for my family and it was a hit. And this year, my mom requested that we make the meal as the centerpiece of our Christmas spread!”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Resolution got you down? Stanford expert recommends “everything in moderation”

Photo by congerdesign
Photo by congerdesign

I don’t usually make New Year’s resolutions, but this year is the exception. My life has gotten too sedentary as a freelance writer who works at home. Like most Americans, I need to exercise more and eat healthier. It’s time to stop the holiday binge eating.

So I welcomed the good advice of Marily Oppezzo, PhD, a registered dietician and postdoctoral fellow at the Stanford Prevention Research Center, who specializes in helping people improve their health and well-being. In a recent Stanford BeWell article, she provides guidance to those hoping to make healthier lifestyle choices.

Oppezzo recommends that we stop classifying foods as sinful or good. “While some decisions are arguably healthier than others, we certainly don’t need to get our character and sense of self involved, a mind game that sets health up as binary, rather than a spectrum,” she says in the article. This all-or-nothing thinking, she argues, can result in binge eating — eating one “bad” cookie can lead to eating a whole bag, since you’re already “off the wagon.”

Instead, she says it is better to relish the taste of your favorite food without “pouring guilt all over it,” because you’re more likely to be satisfied and eat less of it.

If you make only one small dietary change, she suggests that you eat more vegetables. “Find one vegetable you love that is quick and easy for you to prepare and eat — and even defrosting frozen spinach to add to a soup or mixing in pre-packaged riced cauliflower … counts! Bring your veggie to work, and add [it] to three lunches next week,” says Oppezzo.

In terms of exercise, she said she thinks walking is particularly underrated. Walking can help your joints, improve your cognitive and creative thinking, reduce your stress level and provide a way to socialize with friends, she said.

However, it is important to be realistic when setting your health goals for this year — and tailor your plan to fit your personal likes and limitations. “In fact, it is important to weigh the factors of culture, individual circumstance, and motivational readiness when advising any (very young to very old) age segment of the population,” Oppezzo said.

And a parting word of wisdom? “’Everything in moderation’ turns out to be so true!,” Oppezzo said.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Bread baking becomes business for Stanford infectious disease researcher

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Photograph courtesy of Fiona Strouts

Making bread is an art, science and passion project for Fiona Strouts, PhD, a Stanford research scientist in infectious diseases.

Her baking began as a hobby several years ago, but now Strouts operates a business, L’atelier du Pain, and sells her whole-grain bread at the Portola Valley Farmers Market. I exchanged emails with her recently about her work as a professional baker and Stanford researcher.

How did you start baking bread?

“I learned to make bread about eight years ago from my Italian housemate when I lived in London during graduate school. She taught me to make 100 percent whole-wheat sourdough bread that we would bake together on the weekends. The bread was fairly dense, and provided good fuel for cycling.

I now make whole-grain, naturally leavened breads using mostly California-grown wheat. The favorite seems to be the Sprouted Lentil & Rye bread. But my personal favorite for every-day eating is the Sonora Field Blend; it has great flavor and aroma. Sonora wheat was one of the first varieties planted in California in the early 1800s.” 

I’ve heard that you grind your own wheat. Why?

“Yes, I stone-grind my own wheat because I want to capture the flavor and nutrients, which come mostly from the germ and bran portions of the wheat berry. I buy bags of wheat berries directly from farmers, and then mill them into flour right before I mix the dough. Milling the wheat myself also ensures that the flour is 100 percent whole grain. Wheat is very nutrient-dense compared with other grains, but only when it is in the truly whole-grain form — nothing added and nothing removed from the original wheat grain.”

Why did you decide to turn your hobby into a business?

“A number of things inspired me, and they all came together a few months ago. I grew up in France, and in the village where my parents live there was a local baker and friend. The highlight of the week was going to the market on Saturday and then stopping by his house to pick up bread. There would be others from the village there and we’d share a savory pastry and a glass of wine before picking up the bread and going home for lunch. I miss that sense of community and I wanted to re-create something similar.

Then, almost a year ago I started learning more about all of the farmers in California who are passionate about sustainable agriculture and who are growing different varieties of wheat —both ancient and modern. I loved discovering the different flavors and properties of these wheats for bread making.

In addition, I’ve always been very interested in health and population health. Making whole-grain, naturally leavened breads is a way to provide a healthy option for people.”

How do you juggle baking, running a business and doing research?

“Good question! It takes organization and prioritization. I used to bike race, and the training required a lot of discipline. But starting the business was less structured and it took longer than I thought it would, as I was doing it in my spare time. I spent several weekends practicing baking large batches of bread and sharing it with some of my labmates, which I think they appreciated. The market is one day per week and it’s a manageable scale for one person. I’ve reduced my full-time equivalent [work] hours accordingly to be able to do both and my advisor has been very supportive.”

Explain your research at Stanford. Has it given you any insights into bread making?

“I work in the lab of David Relman, MD, on a project focused on improving the diagnosis and prognosis of systemic infections in humans, using sequencing of both microbial nucleic acids and host transcripts derived from blood. I am trying to understand what those blood profiles look like during states of health. And whether we’re able to detect the presence of bacteria in the blood of healthy people, to help interpret what we see in sick individuals with suspected infections.

My background has helped me understand sourdough bread making from the aspect of microbial fermentation and the effects of time and temperature. I’ve actually become quite a keen home fermenter. I have various other projects going — including yoghurt, kefir, kombucha, shoyu and miso — for which I converted the dishwasher into a fermentation chamber with a little space heater. Both baking and cooking are science, so it has also helped more generally in figuring out the properties of different types of wheat. I run a lot of bread experiments at home!”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

‘Eat a bleeping Dorito’: An elite runner and Stanford medical student addresses disordered eating

megan-e1475000985163-300x300Somehow, Megan Deakins Roche balances her roles as a fourth-year Stanford medical student, wife, athlete on the Nike trail running team and, according to her Twitter profile, an ice cream connoisseur. Balance is an underlying theme of her recent article on disordered eating in Trail Runner Magazine.

Disordered eating isn’t quite the same thing as an eating disorder. Many people suffering from disordered eating do not meet the criteria of eating disorders, which are psychiatric illnesses. However, the abnormal thoughts and behaviors of disordered eating can lead to serious health problems, including developing an eating disorder. Both disordered eating and eating disorders can affect people of any size or gender.

Roche writes:

“We live in a culture of fad diets and fad exercise philosophies. You can choose to be gluten-free, vegan, Paleo or even fruitarian. You can log 120 miles a week on Strava, do CrossFit until you pee blood or do hot yoga until your core temperature and skin texture resemble a Thanksgiving turkey.

Some of these actions have become socially acceptable. Heck, some have made champions. So how do we draw the line? When does disciplined eating morph into disordered eating, and when does disordered eating slip into a life-threatening disorder?”

She explains that it is important to understand the warning signs of disordered eating, which can include:

  • Chronic yo-yo dieting
  • Fasting or skipping meals regularly
  • Avoiding social events where food is served
  • Rigid compulsive exercise routines
  • Self esteem that is highly based on body weight
  • Preoccupation with food, body and exercise that causes distress

Roche gives the example of Kara Goucher, who overcame disordered eating as a collegiate runner before competing in the 2008 Olympics in the 10k and the 2012 Olympics in the marathon. In a video, Kara describes the moment she realized she had an eating problem. While on a date with her boyfriend (now husband) Adam Goucher, he offered her some Doritos as a snack since she was too hungry to wait for dinner. When Kara repeatedly refused the chips, Adam said, “Eat a bleeping Dorito” — a now oft-repeated quote among elite runners.

Roche focuses her piece on the pervasiveness of disordered eating within the running community, which often associates weight loss with faster times. She argues that trail running requires strength and resilience, whereas disordered eating weakens musculoskeletal strength and increases the risk of stress fractures, soft-tissue overuse injuries and depression.

“These issues are common for runners, and confronting them head-on is the best way to get healthy and stay healthy long-term,” she says in her piece. She later adds, “The only way for us to squash the stigma (and possibly save running careers and even lives) is to practice consistent empathy, as individuals and as a unified community.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.