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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

In the News, Infectious Disease, Nutrition, Pediatrics

Raw milk still a health hazard, says Stanford doctor

Raw milk still a health hazard, says Stanford doctor

MoooooooIn spite of looser regulations around the sale of unpasteurized milk, it’s still unsafe to drink. That’s the message from Stanford pediatric infectious disease expert Yvonne Maldonado, MD, who is quoted in a new story on Today.com about the relaxation of raw-milk regulations in West Virginia and Maine.

In the United States, each state writes its own rules for in-state sales of raw milk, and they vary — a lot. Until last week, West Virginia required all dairy products sold in the state to be pasteurized, or heated briefly to kill germs. The state’s new laws allow for “cow shares,” in which individuals can pay to share ownership of a cow in exchange for some of the cow’s unpasteurized milk. Maine, meanwhile, is considering relaxing its license regulations on farmers who sell milk directly to consumers. (Other states take different approaches, ranging from entirely banning raw milk sales to allowing it in retail stores.)

Raw-milk aficionados claim that unpasteurized dairy products are safe and have health benefits.

Not so fast, says Maldonado, who was the lead author of the American Academy of Pediatrics’ 2013 policy statement discouraging the consumption of raw milk. In the Today.com story, she explains:

“People want to be more responsible for their sustainable environment and what they are putting into their bodies but they conflate the two issues because natural doesn’t always equal healthy,” says [Maldonado].

… “Our recommendations are evidence-based and there is no scientific evidence that drinking raw milk is better than drinking pasteurized milk and milk products,” says Maldonado, an infectious disease expert and pediatrician at Lucile Packard Children’s Hospital. “But we do see a very large number of diseases and illnesses from raw milk and raw milk products and the infections can be just horrible,” causing diarrhea, fever, cramps, nausea and vomiting, and some may even become systemic.

Previously: Stanford pediatrician and others urge people to shun raw milk products and Stanford study spoils hopes that raw milk can aid those who are lactose-intolerant
Photo by Steven Zolneczko

Mental Health, Nutrition, Pediatrics

Incorporating the family in helping teens overcome eating disorders

Incorporating the family in helping teens overcome eating disorders

Apple on plateLearning that your teen has an eating disorder is baffling and deeply troubling news for parents. Our instincts are to protect and try to help our children out of the morass, but for decades, families were kept out of the treatment loop for teens with conditions like anorexia and bulimia.

The team at the Comprehensive Eating Disorders Program at Lucile Packard Children’s Hospital Stanford, led by psychiatrist James Lock, MD, PhD, is integrating the family into helping teens overcome their eating disorders. Lock recently sat down with the Stanford Medicine Newsletter for an informative Q&A about teen eating disorders.  He spoke about the historic reasoning for cutting parents out of treatment plans:

For most of the early 20th century, parents were erroneously blamed for mental illnesses in their offspring: So-called refrigerator mothers (those lacking warmth) caused autism, and overcontrolling parents caused anorexia nervosa, experts claimed. These ideas about causation are without foundation.

Research at Stanford and elsewhere has shown that parents can play a big role in helping their teens recover from eating disorders. For example, we have demonstrated that a specific family-based therapy is twice as effective as individual psychotherapy for treating anorexia nervosa.

And what to watch for in teens:

Warning signs include changes in eating patterns, skipping meals, increased driven exercise or discussion about weight, avoidance of desirable but calorically dense foods, refusing to eat with the family, vomiting, large amounts of food missing from the refrigerator and increased irritability and emotionality. If a parent sees these signs, it would be a good idea to make an appointment for an evaluation and consultation.

The full Q&A is worth a read.

Previously: Families can help their teens recover from anorexia, new study showsA growing consensus for revamping anorexia nervosa treatmentPossible predictors of longer-term recovery from eating disordersWhat a teenager wishes her parents knew about eating disorders and Research links bulimia to disordered impulse control
Photo by daniellehelm

Immunology, In the News, Nutrition, Pediatrics, Research

Peanut products and babies: Now okay?

Peanut products and babies: Now okay?

peanut butter2 - big

Updated 2-25-15: Allergy expert Sharon Chinthrajah, MD, discussed the study and its implications on KQED’s Forum today:

***

2-24-15: Any parent of young children is likely familiar with the warnings: It’s not okay to give your baby peanut butter, or any other peanut product, before he or she turns one. Don’t do it! These instructions are so imprinted on my brain that I practically did a double-take when I came across headlines about new research suggesting that infants should, indeed, be fed peanut products – in order to prevent the development of peanut allergies.

This isn’t the first time that the benefits of giving allergenic foods to babies have been outlined, but the language surrounding this study has been particularly strong. As the writer of a New York Times blog entry explained, the authors of the study and accompanying editorial “called the results ‘so compelling’ and the rise of peanut allergies ‘so alarming’ that guidelines for how to feed infants at risk of peanut allergies should be revised soon.” He went on to outline the study findings:

In the study, conducted in London, infants 4 to 11 months old who were deemed at high risk of developing a peanut allergy were randomly assigned either to be regularly fed food that contained peanuts or to be denied such food. These feeding patterns continued until the children were 5 years old. Those who consumed the foods that had peanuts in them were far less likely to be allergic to peanuts when they turned 5.

After hearing the news, I reached out to the folks at the Sean N. Parker Center for Allergy Research at Stanford to get their take on the findings. Sharon Chinthrajah, MD, a clinical assistant professor of medicine, explained that this work is the first randomized controlled study to look at how to prevent peanut allergies. She told me:

We’ve all been waiting for the results of this landmark study to confirm the shift in the paradigm of when to introduce foods into the diet. Early introduction of peanut in the right infants can prevent peanut allergy. Dr. [Gideon Lack, the leader of the study] and colleagues were able to show an 80 percent reduction in peanut allergy in children who started eating peanut early and incorporated it into their regular diet.

Chinthrajah believes the guidelines on babies and peanut products should be revised, “because peanut allergies affect 2 percent of our population in the U.S. and most people do not outgrow this allergy.” But, as other experts have done, she cautions that not everyone should introduce peanuts and other foods into their diet early. “Those who are ‘high-risk’ – who have other allergic conditions such as eczema or other food allergies – should consult with their allergist to see if it would be safe to introduce peanut into their child’s diet,” she advised.

Previously: Taking a bite out of food allergies: Stanford doctors exploring new way to help sufferers, Simultaneous treatment for several food allergies passes safety hurdle, Stanford team shows, Researchers show how DNA-based test could keep peanut allergy at bay, A mom’s perspective on a food allergy trial and Searching for a cure for pediatric food allergies
Photo by Anna

Autoimmune Disease, Chronic Disease, Health and Fitness, Nutrition, Obesity, Research

Study clarifies link between dieting, exercise and reduced inflammation

Study clarifies link between dieting, exercise and reduced inflammation

4503404991_13da58b6e6_bIf you’ve ever wondered how dieting and exercise reduce inflammation, read on. According to new research, a compound that our bodies crank out when energy supplies are low could be the link between diet and exercise, and reduced swelling in the body.

When diet, fasting and exercise starve the body for calories, the body increases production of a compound called beta hydroxybutyrate (BHB). This compound has long been known as an alternate source of energy; the new research suggests that BHB can also block the inflammatory response.

In their study, published this week in Nature Medicine online (subscription required), a team of scientists co-led by Yun-Hee Youm and Kim Yen Nguyen at the Yale School of Medicine, discovered that the compound BHB reduces swelling in the body by inactivating a group of proteins, called the inflammasome, that drive the inflammatory response.

The research team used human immune cells and mice to explore the effects of BHB in the body. They found that mice given BHB directly, and mice fed a low-carbohydrate diet (that prompted their bodies to synthesize their own BHB), both benefited from reduced inflammation.

These results are noteworthy because a better understanding of the mechanism that links diet, exercise and inflammation could help scientists develop more effective treatments for inflammatory disorders such as Type 2 diabetes, atherosclerosis and Alzheimer’s disease.

Previously: Newly identified type-2 diabetes gene’s odds of being a false finding equal one in 1 followed by 19 zeroesImproving your health using herbs and spices, Exercise may alleviate symptoms of arthritis regardless of weight loss, Study points to inflammation as cause of plaque buildup in heart vessels and Examining the role of exercise in managing and preventing diabetes
Via ScienceDaily
Photo by Dave Nakayama

Ask Stanford Med, Events, Nutrition, Obesity, Stanford News

Sticky situation: How sugar affects our health

Sticky situation: How sugar affects our health

132244825_dbf0e21d9f_zHere’s a shocking statistic: On average, Americans consume three pounds of sugar each week, or 3,550 pounds in an entire lifetime. This leads some to blame the sweet stuff for the increase of chronic disease in modern society. But simply reducing our sugar intake is easier said than done, in part because identifying foods with added sugars can be tricky.

This Thursday, Alison Ryan, a clinical dietician with Stanford Health Care, will deliver an in-depth talk on sugar and our health as part of a Stanford Health Library lecture series. Those unable to attend can watch the presentation online here.

In the following Q&A, Ryan discusses the controversies surrounding sugar and the role of sugar in our diet, and she offers tips for making sure your consumption doesn’t exceed daily guidelines.

Why does our body need sugar?

Sugar, in the form of dextrose or glucose, is the main fuel or energy source for the cells of the human body. Without glucose, our body has to get creative and rely on other metabolic pathways, like ketosis, to keep our brain and other organs running. There is an optimal range for our blood sugar levels, and our bodies are making constant efforts to keep blood sugar within this range.

Our body can make glucose from any carbohydrate that is consumed, so consuming monosaccharide (glucose and the like) is not biologically required. This is one of the reasons it’s difficult to determine the right amount of sugar that is required for the human body. Do we think of the optimal amount as the amount needed to function at peak level? Or an amount not to go over in order to avoid detrimental effects on our health?

Sugar intake has been on the rise in human diets. Why do you think that is?

At one time, sugar used to be a seldom available food item. It is now ubiquitous and more of a hallmark for highly processed, low nutritional value foods. Now, consider the food industry and the politics of sugar. Soda companies, makers of desserts, cakes, sugary snack foods, the sugar and corn syrup refiners all lobby to keep their products “part of a balanced diet.” The food industry is deeply involved (or at least vocal about) the food and nutrition guidelines in the U.S. Then there’s the reality that sugar tastes good! Most people enjoy the taste of sweet foods and are drawn to consuming them.

What are some of the health risks of consuming too much sugar?

Sugar has been implicated as playing a role in some obvious ways, like obesity, diabetes, and tooth decay; but also in less direct appearing ways such as heart disease, chronic inflammatory conditions, cancer, etc. Often, when we’re consuming foods high in sugar, we’re not consuming foods that are rich in nutrients. These calorie-dense foods displace the nutrient-dense foods. The net effect is higher intake of calories, with concurrent lower intake of vitamins, minerals, phytonutrients, protein, etc.

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Clinical Trials, Nutrition, Pediatrics, Research, Stanford News

Batman has his utility belt – and I have my EpiPen

Batman has his utility belt - and I have my EpiPen

Batman“Matt, do you have your EpiPen?” Those six words have echoed throughout my house each morning ever since I could understand them.

“Matt, do you have your EpiPen?” “Matt, do you have your EpiPen?” “Matt, do you have your EpiPen?” How many times have I heard that? Thousands. Growing up with a food allergy was a huge burden requiring constant vigilance. Vigilance about carrying my EpiPen and about knowing where to sit at the school lunch table, who would chaperone the field trip, whose birthday party my mom or dad would have to hang out at, whose house was safe for me to hang out at – and vigilance about which foods I eat.

Since enrolling and subsequently graduating from a Stanford food allergy study led by Kari Nadeau, MD, PhD, my anxiety surrounding my allergy has greatly decreased, but my vigilance remains steadfast. The Stanford study has given me safety from cross contamination and a life without fear.

Yet, just as Batman has his utility belt, I have my EpiPen. The EpiPen may as well be tattooed on to my skin, as it still travels with me everywhere I go. In my opinion, this should be the same for every severely allergic person. My good friend (who has multiple food allergies) doesn’t carry one when he’s with me. His rationale behind it is, “I’m with you, so I don’t need one.” I recently met someone who doesn’t carry an EpiPen although she has a diagnosed anaphylactic allergy to tree nuts and peanuts. Her rationale? “I’ve never had a reaction, and I am really careful about what I eat.”

I can’t understand when I meet people with food allergies and they don’t carry an EpiPen. Sometimes they say, ” I just get hives around my mouth.” Or “I just get a little itchy on my tongue.” Or “I have one – it’s in my car.” CAN YOU BE SERIOUS?

Unfortunately for me, before entering the allergy study, I had to use my trusted EpiPen several times. It was very tense, scary and thankfully quick. After a person gets over the paralyzing fear of the needle (which is actually hidden inside the pen), the EpiPen is actually easy to use (once you get the hang of it). It works so fast. It actually stops the allergic reaction in its tracks. It’s the only life-saving medication food that allergic people can use to help prevent life threatening reactions.

So yes, under the advice of my doctor, I still carry an EpiPen. Even though I successfully eat a lot (4,000 milligrams each) of all of my allergens daily, (which are wheat, rye, barley and oats), it’s always by my side – at camp, tennis, school or a party. I know the facts of how quickly a reaction can escalate, and I may still have a reaction. I am after all, a living science experiment.

The words, “Matt, do you have your EpiPen?” are still essential to my life.

Matthew Friend is a high-school junior from Chicago. A version of this piece originally appeared in the Huffington Post.

Previously: Participant in Stanford food-allergy study delves into lifestyle-changing research, Taking a bite out of food allergies: Stanford doctors exploring new way to help sufferersSimultaneous treatment for several food allergies passes safety hurdle, Stanford team shows, Researchers show how DNA-based test could keep peanut allergy at bay and A mom’s perspective on a food allergy trial and Searching for a cure for pediatric food allergies
Photo by JD Hancock

Nutrition, Obesity, Research, Stanford News

New insulin-decreasing hormone discovered, named for goddess of starvation

New insulin-decreasing hormone discovered, named for goddess of starvation

530468355_133d4da701_zLimos, the Greek goddess of starvation, must have relied on limostatin, the eponymous hormone recently discovered by Stanford researchers, to survive hunger.

She was clearly not well fed. As Ovid writes: “Her hair was coarse, her face sallow, her eyes sunken, her lips crusted and white; her throat scaly with scurf. Her parchment skin revealed the bowels within…”

Limostatin slashed her insulin levels, keeping nutrients in her blood so they could be used. Without limostatin, humans develop diabetes-like symptoms such as low blood sugar and a tendency toward obesity.

From our press release describing the Stanford work:

The researchers first discovered limostatin in fruit flies but then quickly identified a protein with a similar function in humans.

“Starvation or famine is an ancient, ever-present specter faced by all living organisms,” said Seung Kim, MD, PhD, professor of developmental biology. “The ways to deal with it metabolically are likely to be ancient and conserved. This research clearly connects the dots between flies and humans, and identifies a new potential way to regulate insulin output in humans.”

The researchers discovered limostatin by following a series of “biological breadcrumbs:”

Kim and his colleagues withheld food from their laboratory fruit flies for 24-28 hours and looked to see which genes were highly expressed during this time. They narrowed the list to those genes that encoded proteins resembling hormones, which are special signaling molecules that circulate throughout the body to affect the function of distant cells. They observed that one of these, limostatin, caused characteristics of insulin deficiency when overexpressed in flies…

Once the researchers had identified the receptor for limostatin in fruit flies, they looked to see if it resembled any human protein. A trail of biological breadcrumbs led them to the receptor for a protein called Neuromedin U. The protein is produced in the brain, and controls a variety of physiological responses including smooth muscle contraction, blood pressure control, appetite and hormone function in humans.

Based on their experiments in fruit flies, Kim and his colleagues expected that Neuromedin U might also be important in insulin regulation. They found that the protein is also expressed in the stomach and intestines, and the Neuromedin U receptor is found on insulin-producing beta cells in the pancreas. Neuromedin U and its receptor appeared to neatly connect nutrient sensing in the gut with insulin-producing cells elsewhere in the body.

Previously: Tiny fruit flies as powerful diabetes model, Beta cell development explored by Stanford researchers and Correspondence on the discovery of insulin
Photo by William Murphy

Health and Fitness, Nutrition, Public Health

Why establishing a health baseline is a “critical starting point for achieving future health goals”

Why establishing a health baseline is a "critical starting point for achieving future health goals"

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Raise your hand if you want to be more successful at achieving health goals, such as losing weight or lowering your cholesterol levels, and maintaining a healthy lifestyle. Perhaps it’s time to consider creating a health baseline. “A health-care baseline is essentially where you are “at” on the broad, complex spectrum of physical, mental and emotional health,” explains Mary James, MD, an internal medicine physician at Stanford. “This can be a critical starting point for achieving future health goals.”

On Thursday, James will deliver an in-depth talk on the benefits of partnering with your primary care provider to establish a health baseline as part of the Stanford Health Library lecture series. Those unable to attend can watch the presentation online here.

In anticipation of the event, I contacted James to learn more about why its important to have a basis for comparison, beyond the ever-fluctuating number on your bathroom scale or if you’re able to fit into your skinny jeans, to use in measuring progress in meeting your health goals. Below she discusses how assessing the state of your health now can pay off in a longer, more active life in the future.

What is a health baseline?

Your baseline has two basic components: existing illness and potential future illness. Your current baseline has been shaped by your medical, social and family history and is constantly being influenced by common factors in everyday life. Although some components of your healthcare baseline are more modifiable than others, it is important to have an accurate understanding of your current health status.

Why is it important to determine your personal health baseline?

You may be thinking, “I’m healthy – I take no medications and never go to the doctor. Why should I start now?” There are two fundamental components to good health. They are: appropriate treatment for current illness and appropriate preventative care to reduce health decline in the future. While most people actively seek care for the former, we often forget about the latter. Although the data is mixed on whether “routine check ups” are beneficial, there is strong evidence behind many of the preventative maneuvers that are typically discussed and ordered at these visits. Taking appropriate preventative health-care steps can help you avoid the need for prescription medications, hospitalizations and procedures and can help ensure a longer, healthier life.

How can establishing a health baseline help you be more successful in reaching personal wellness goals?

Many wellness goals start with changes in diet and exercise. Your primary care provider can help determine how to start making these changes in a safe, effective manner. Are there exercises you should avoid due to chronic back pain? Is it okay to start running if you have high blood pressure? Is it safe for you to start a vegan diet? What is a safe amount of weight to lose?

Wellness also includes mental and emotional health. Your primary provider can help determine what treatment is most appropriate for common conditions such as depression and anxiety. Maybe you’ve been feeling “down” lately – is this true depression that warrants medical treatment, or is it safe try a new yoga or meditation class first? These are just a few of the many things that can be assessed and addressed as part of your health baseline. Together, you and your primary care provider can prioritize health problems and determine effective interventions.

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Nutrition, Public Health

Eating for good blood: Tips for boosting iron levels and hemoglobin

Eating for good blood: Tips for boosting iron levels and hemoglobin

eggs and chard

Have you ever gone to donate blood only to be deferred for low iron count? Also referred to as low blood count, low iron, or low hemoglobin, approximately 10 percent of donors are deferred for this reason. When a donor is deferred, that means they’re unable to donate blood that day. You’ve probably wondered why this happens and if there’s anything you can do about it. Hopefully, the following information will shed some light on the subject.

What is iron and what does it have to do with blood donation?

Iron is a nutrient that is found in the foods we eat, which then combines with certain proteins to become hemoglobin in your red blood cells. The red blood cells are important because they carry oxygen from the lungs to other parts of the body. When the body experiences low iron and hemoglobin, this essentially means you do not have enough red blood cells in your body to donate blood. Low iron levels may cause you to feel tired, and extremely low iron levels may cause damage to organs. There are several reasons one may have a low blood count – including not eating enough iron-rich foods, donating blood too frequently, chronic illness, or other invisible causes.

Testing your blood

In order to keep our donors safe and healthy, our collections staff must ensure that each donor we see has sufficient levels of iron and hemoglobin before they donate. Therefore, when you visit a center to donate, the collections staff will do a finger prick to test a small amount of blood to assess hemoglobin levels. If your levels are low, we will not be able to collect your blood that day but do encourage you to try some simple measures to raise your levels in order that you can come back to donate again in the future.

What can I do to improve my hemoglobin levels prior to donation?

One way to try to boost your iron levels is through your diet. By eating iron-rich foods, you can promote blood regeneration and increase the amount of iron in your body. Typically, iron-rich foods are colorful and deeply pigmented. Some examples of good sources of iron include:

  • Chard
  • Dates
  • Eggs
  • Lean beef and pork
  • Raisins
  • Shrimp
  • Spinach
  • Whole grain breads

For a more detailed list of foods and their iron content, the USDA provides a nutrient database for reference.

Kristin Stankus is the digital community & social media specialist at Stanford Blood Center. This blog entry originally appeared on the blood center’s blog.

Photo by Patent and the Pantry

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