Five things everyone should know about . . . Pulses

1. You’ve eaten them without knowing it. If the word “pulse” as a food leaves you flummoxed, fear not. The word pulse comes from the Latin word “puls,” which means thick soup or potage. No doubt you’ve enjoyed dried beans, lentils and peas in a soup or stew. Pulses are the edible dried seeds of certain plants in the legume family. Soybeans, peanuts, fresh peas and fresh beans are legumes but not considered pulse crops. Some lesser-known pulses like adzuki bean and cowpea play critical roles in diets around the world. Many pulses are economically accessible and important contributors to food security.

2. They’re very nutritious. Pulses contain between 20 and 25 percent protein by weight—twice the amount you’ll find in quinoa and wheat—and next to no fat. Around the world, they are a key source of protein for people who don’t eat meat or who don’t have regular access to meat. Pulses need less water than other crops, which adds to their appeal and value in areas where water is scarce.

3. Pulse crops have other environmental benefits as well. As members of the legume family, pulses are capable of taking nitrogen from the air and putting it back in the soil in a form available to plants. This makes legumes a critical part of any crop rotation and contributes significantly to sustainable farming. Pulses are grown worldwide but are particularly well adapted to cool climates such as Canada and northern states in the U.S.

4. We’re learning a lot about pulses from a recently sequenced genome. Adzuki bean was domesticated 12,000 years ago in China and is one of the most important pulses grown in Asia. There it is known as the “weight loss bean” because of its low calorie and fat content and high levels of protein. A recent genome sequencing collaboration among scientists in India and China revealed that genes for fat were expressed in much higher levels in soybean than in adzuki bean, while genes for starch were expressed at greater levels in adzuki bean. Their findings suggest that humans selected for diversified legumes in their diet—some that would provide oil and others that would provide starch.

5. It’s their year! The 68th UN General Assembly declared 2016 the International Year of Pulses, so now is the time to eat and learn. Events taking place all around the world focus on everything from cooking pulses (sample recipes: fava bean puree, carrot and yellow split pea soup) to growing them and incorporating them into school lunches. Learn more at www.fao.org/pulses-2016/en/.

Five things everyone should know about gluten

1. What is it? Gluten is a substance composed of two proteins—gliadin and glutenin—that are found in the endosperm (inner part of a grain) of wheat, rye, barley and foods made with those grains, meaning that gluten is widespread in a typical American diet.

2. Is it harmful? People who suffer from celiac disease, an autoimmune digestive disorder, are unable to tolerate gluten. Even a small amount of it (50 milligrams) can trigger an immune response that damages the small intestine, preventing absorption of vital nutrients and potentially leading to other problems such as osteoporosis, infertility, nerve damage and seizures.

3. How widespread is celiac disease? An estimated 1.8 million Americans have celiac disease; as many as 83 percent of those suffering from it remain undiagnosed or are misdiagnosed with other conditions. Another 18 million (about 6 percent of the population) do not have celiac disease but suffer from gluten sensitivity. They report such symptoms as diarrhea, constipation, bloating and abdominal pain—which also are symptoms of celiac disease—but do not experience the same intestinal damage. For those with celiac disease or gluten intolerance, a gluten-free diet is beneficial.

4. Should you cut gluten from your diet even if you don’t have these conditions? Probably not. Restriction of wheat in the diet often results in a decrease in the intake of fiber at a time when most Americans consume significantly less than the recommended amount. Low-fiber diets are associated with increased risk of several acute gastrointestinal diseases (examples: constipation, diverticulosis) and chronic diseases such as heart disease and colon cancer. If not done carefully, gluten-free diets also tend to be low in a number of vitamins and minerals.

5. Don’t diagnose yourself. The broad range of symptoms associated with celiac disease and gluten sensitivity may be due to other causes; self-diagnosis and treatment of perceived gluten intolerance may delay someone from seeking more appropriate medical care. The only way to know for certain if you have celiac disease is from a blood test for the presence of specific antibodies followed by a biopsy of the small intestine. If you are experiencing the symptoms described above, please seek medical care.

Beth Olson is a professor of nutritional sciences. Her principal research areas concern breastfeeding support and improving infant feeding practices in low-income families.

Catch up with … Carl T. Wahl

Carl Wahl’s interest in farming was sparked during a stint with the Peace Corps in Zambia, a landlocked country in southern Africa. His work on maternal and child health and nutrition led him into agriculture as he sought to integrate edible legumes into local farms and diets. Wahl returned to the U.S. to study agroecology at CALS and then went back to Africa, first with the Peace Corps and now with the Ireland-based charity Concern Worldwide, which he serves as the conservation agriculture coordinator in Zambia and neighboring Malawi.

What’s your understanding of “conservation agriculture”? Conservation agriculture (or CA) is a practice to retain moisture and nutrients in the soil to boost short-term crop productivity and long-term sustainability of farmland. CA is essentially a combination of three principles: minimum tillage, retaining soil residues and crop rotation with legumes.

It is similar to what is increasingly a practice in the Midwest. However, in Zambia, Concern Worldwide is working with the poorest (i.e., resource-limited) farmers, who essentially have a hoe and possibly an axe as their entire repertoire of farming tools and farm in an incredibly less forgiving environment. Therefore we include such sustainable agriculture aspects as agroforestry, supplemental mulching and microdosing of inputs (fertilizer, manure, compost, indigenous tree leaves, wood ash, etc.) in order to better translate limited funds and labor into greater yields.

How does conservation agriculture work in Zambia and Malawi? In either country, the word “food” means maize (corn), specifically maize meal for a dish called nshima. Both countries consider nshima a staple food to the extent that they rank in the world’s top three per capita direct consumers of maize. However, a heavy feeder like maize in an environment with limited nutrient (fertilizer) supply and undependable rainfall is an unreliable crop. In Malawi and Zambia, CA practices help mitigate much of the risk associated with growing maize. Additionally, CA’s capacity to include legume crops provides more protein to the household’s diet.

How have you seen conservation agriculture help people? The Western Province of Zambia, where I work, is situated on a drift of eolian sand that is roughly the size of Wisconsin. In the 2012–2013 season, our cumulative rainfall was above normal; however, instead of being distributed over four to five months as usual, we received two-thirds of it over 4.5 weeks and the other third in three days. All the conventional maize failed. Though the CA farmers were also affected, nearly everyone reported that without CA, they would have had no maize whatsoever. That is a pretty powerful incentive to adopt the technology.

What projects are you most excited about?  The first is our effort to engage and develop certified seed grower groups on a larger scale to provide a variety of quality seed to farmers at lower cost. We are over 300 miles from most of the seed producers in Zambia, so bringing that resource closer can really relieve the chronic pressure of getting an adequate and high-quality seed supply.

The second is use of the burgeoning mobile phone network to send text messages that can pass on Extension messages as well as market information to farmers, enabling them to both produce more and sell more at a better price. The potential ability to transmit information quickly and cheaply could be a real game-changer in our agriculture picture in both Zambia and Malawi.

The Value of GMOs

For all the discussion surrounding genetically modified foods, there have been strikingly few comprehensive studies that put a numeric value on the costs and benefits.

Now there’s more to talk about.

By analyzing two decades’ worth of corn yield data from Wisconsin, a team of CALS researchers has quantified the impact that various popular transgenes have on grain yield and production risk compared to conventional corn. Their analysis, published in Nature Biotechnology, confirms the general understanding that the major benefit of genetically modified (GM) corn doesn’t come from increasing yields in average or good years—but from reducing losses during bad ones.

“For the first time we have an estimate of what genetically modified hybrids mean as far as value for the farmer,” says CALS and UW-Extension corn agronomist Joe Lauer, who led the study.

Lauer has been gathering corn yield and other data for the past 20 years as part of the Wisconsin Corn Hybrid Performance Trials, a project he directs. Each year his team tests about 500 different hybrid corn varieties at more than a dozen sites around the state, with the goal of providing unbiased performance comparisons of hybrid seed corn for the state’s farmers. When GM hybrids became available in 1996, Lauer started including them in the trials.

“It’s a long-term data set that documents one of the most dramatic revolutions in agriculture—the introduction of transgenic crops,” says Lauer, who collaborated with CALS agricultural economists Guanming Shi and Jean-Paul Chavas to conduct the statistical analysis, which considered grain yield and production risk separately.

Grain yield varied quite a bit among GM hybrids. While most transgenes boosted yields, a few significantly reduced production. At the positive end of the spectrum was the Bt for European corn borer (ECB) trait. Yield data from all of the ECB hybrids grown in the trials over the years showed that ECB plants out-yielded conventional hybrids by an average of more than six bushels per acre per year. On the other hand, grain yields from hybrids with the Bt for corn rootworm (CRW) transgene trailed those of regular hybrids by a whopping 12 bushels per acre. But even among poor-performing groups of GM corn, there are individual varieties that perform quite well, Lauer notes.

Where transgenic corn clearly excels is in reducing production risk. The researchers found that every GM trait package—whether single gene or stacked genes—helped lower variability. For farmers, lower variability means lower risk, as it gives them more certainty about the yield levels they can expect.

Lauer equates choosing GM crops with purchasing solid-performing, low-risk stocks. Just as safe stocks have relatively low volatility, yields from GM crops don’t swing as wildly from year to year, and most important, their downswings aren’t as deep.

GM crops help reduce downside risk by reducing losses in the event of disease, pests or drought. Economists Shi and Chavas estimated the risk reduction provided by modified corn to be equivalent to a yield increase ranging from 0.8 to 4.2 bushels per acre, depending on the variety.

Risk reduction associated with GM corn can add up to significant savings for farmers—as much as $50,000 for 1,000 acres, calculates Lauer. “It depends on the price that farmers can receive for corn,” he says.

But the two factors quantified in this study—yield and production risk—are just part of the overall picture about GM crops, says Lauer. He notes there are other quantifiable values, such as reduced pesticide use, as well as ongoing concerns about the safety and health of growing and eating genetically modified foods.

“There’s a lot of concern about this biotechnology and how it’s going to work down the road,” says Lauer, “yet farmers have embraced it and adopted it here in the U.S. because it reduces risk and the yield increases have been as good as—or some would argue a little better than—what we’ve seen with regular hybrid corn.”

Five things everyone should know about… Hazelnuts

1   They’re crazy nutritious and gluten-free. Hazelnuts are rich in vitamins (particularly vitamin E and B-complex groups of vitamins, including folates, riboflavin, niacin, thiamin) as well as dietary fiber. Like almonds, they are gluten-free. They also are rich in monounsaturated fatty acids such as oleic acid and linoleic acid, which help reduce LDL, the “bad” cholesterol, and increase HDL, the “good” cholesterol.

2   An exciting market beckons. Hazelnut oil serves various purposes in the kitchen (most notably as salad and cooking oil) as well as in cosmetics and pharmaceuticals. Kernels can be eaten fresh; used in baked goods, confections and other edibles; or ground for use in nut flours. An appetite is growing for spreadable hazelnut butters (Nutella, anyone?). And then there’s biofuel—the high oleic acid content makes hazelnuts an excellent feedstock for biodiesel and bio-industrial products.

3   They’re good for the environment. As a long-lived woody perennial, hazelnut bush plantings can be used to stabilize sensitive soils and erodible sites. Plantings do not have to be reestablished for decades. They can be closely associated with other high-diversity approaches to agriculture, including agroforestry and multicrop plantings. Since American hazel is a prominent native, there is no risk of invasiveness, and interrelationships to support Wisconsin wildlife are well established. In addition, hazel production readily integrates with small and medium-sized farming operations and family/cooperative farm unit organization.

4   Growers are emerging in the Midwest, including in Wisconsin. Southern Europe is still king in world hazelnut production, with Turkey leading at 75 percent. In the United States, commercial hazelnut production is still limited to the Pacific Northwest, where the climate allows for growing European cultivars. But a number of Midwestern farmers are trying their hand with two species, American (Corylus americana) and beaked (Corylus cornuta), that do well in cold climates and sandy soils. Surveys have identified about 130 hazelnut growers in Wisconsin, Minnesota and Iowa, with nearly 135 acres in production.

5   Important genetics work is underway. Farmers now growing Midwestern hazelnuts are also growing important data as there are, as yet, no commercially proven cultivars of hazelnuts in this region. Breeders are working to develop genotypes focusing on both pure lines of native American hazel and on hybrid crosses between European and American. By selecting from the very diverse native populations and by crossing European with American, they hope to develop a hazelnut shrub with the nut quality and yield of the European and the cold-hardiness and disease tolerance of the American.

 

The Midwest Hazelnut Development Initiative (UMHDI, midwesthazelnuts.org) is a regional collaboration that includes representatives from UW–Madison and UW-Extension.

Jason Fischbach, an agriculture agent with UW-Extension and a program partner with UMHDI, contributed to this piece.

Expanding the Global Classroom

A LITTLE MORE than two years ago I started cold-calling CALS faculty and instructional staff requesting no more than 25 minutes of their time. The first thing I asked the dozens of respondents who agreed to my conversational survey was: “What do you already do to introduce your students to the international aspects of your field?” Then I asked: “What would you do?” And then: “What would you need to do it?”

Their answers were as varied as the sometimes spontaneous, often revisited and always generous conversations I enjoyed over the next few months. Some wanted technical support to connect their classrooms with equivalent courses in other countries. Many were eager to host their international colleagues as guest lecturers. Some envisioned podcasts and websites designed to share relevant teaching resources. Still others conjured up entirely new majors, or a renewed system for rewarding teaching engagement across campus more generally. All of them were eager to tackle the challenge.

In the end, three common needs stood out: more opportunities to collaborate with partners abroad; time to put new teaching projects together; and graduate student assistance to pull it off.

The CALS International Programs Office was prepared to meet those needs with a small awards program under the auspices of the campus-wide Madison Initiative for Undergraduates. International Programs director John Ferrick and undergraduate program development director Laura Van Toll conceived of the program to support science faculty interested in further introducing their students to the international aspects of their fields; I was brought on to help carry it out. We asked for “global learning outcomes” in the awards application so that we could learn the skills and perspectives instructors wanted their students to gain. And we gathered a group of faculty to evaluate and lend insight into the feasibility of their colleagues’ projects.

Catch up with . . . Beth Zupec-Kania

THE SPECIAL DIET SHE WAS USING ON CHILDREN WITH EPILEPSY WAS CHANGING LIVES—but Beth Zupec-Kania BS’81 didn’t know it would change her own until she got a call from Hollywood producer Jim Abrahams back in the mid-1990s.

As a dietitian at Children’s Hospital in Milwaukee, Zupec-Kania and her team had been using the ketogenic diet, a high-fat, low-carb diet—think Atkins—shown to greatly reduce or eliminate seizures. And writer/producer Abrahams (Airplane!, The Naked Gun), whose young son Charlie had been saved by the diet, wanted to partner with her to spread the word.

Charlie had begun having seizures at 12 months, and after going through a half-dozen medications and brain surgery still was having up to 200 seizures a day. “He lived in a car seat,” says Zupec-Kania. “It was the only safe place they could put him because he would have a seizure and just collapse.”

Through his own research Abrahams learned about the diet and took Charlie for treatment at Johns Hopkins, one of relatively few hospitals that offered it. Almost immediately the boy stopped seizing and after a few years was weaned off the diet.

Abrahams formed The Charlie Foundation to promote access to the diet and soon heard that Children’s Hospital in his native Milwaukee had been another early adopter. Abrahams reached out to Zupec-Kania and her team to help them scale up use and start training physicians, nurses and dietitians at other hospitals.

Zupec-Kania found that work so rewarding that eventually she joined The Charlie Foundation full-time, where she writes journal articles and develops online support materials about the diet along with training healthcare professionals. Her work takes her all around the United States and much of the world, including Saudi Arabia (see photo), the Dominican Republic and Germany.

No one knows why this diet works or why it has permanent effects, right?

That’s right, no one knows why the diet affects seizures. But many scientists are trying to solve this mystery—they believe that a healing occurs in the brain. At UW–Madison, physician Carl Stafstrom has done research on this and he’s also treating patients with the diet.

Is the ketogenic diet just for kids?

No. We are finding it works in adults as well. The problem with adults is that compliance with any type of diet is
difficult.

Why is the diet still not a treatment of first resort?

It’s much easier to prescribe a medication, and if clinicians are going to use the diet, they need to have a team in place—a neurologist, a nurse and a dietitian—to initiate and manage it. The diet is not started at home, it’s started in the hospital under medical supervision. Also, there isn’t a treatment code for the diet, so insurance reimbursement is really poor. That’s been a barrier as well.

When you first met Jim, did you feel at all starstruck?

I did! I remember sitting there when he called, thinking “Is this Hollywood producer really talking to me?” But the more I talked to him, the more he seemed like just a regular guy from Milwaukee because he has that familiar accent. He is the nicest man—the most warm, kind, caring person.

More information at charliefoundation.org.

Safer Snacking?

What do Americans love more than french fries and potato chips? Not much—but perhaps we love them more than we ought to. Fat and calories aside, both foods contain high levels of a compound called acrylamide, a potential carcinogen.

First discovered in foods in 2002, acrylamide is produced whenever starchy foods are fried, roasted or baked, meaning that it’s found in everything from doughnuts to coffee beans. But fries and chips are relatively high in acrylamide compared to most starch-based snacks, and potato processors are eager to change that.

CALS plant geneticist Jiming Jiang, a professor of horticulture, has a solution. His lab has developed a promising new kind of potato with reduced levels of acrylamide, an innovation he created with support from USDA-ARS plant physiologist Paul Bethke, a professor of horticulture. As a bonus, these potatoes also could help producers significantly reduce food waste.

The problem starts with storage. Because fry and chip processors need potatoes year-round, most of the fall harvest goes into storage, where low temperatures can cause simple sugars to accumulate in the tubers, a phenomenon known as “cold-induced sweetening.” During cooking, those sugars react with free amino acids to produce acrylamide. The same reaction also causes fries and chips to turn dark brown during processing, making them unsalable.

Jiang’s solution is to insert a small segment of a potato’s own DNA back into its genome. The extra DNA helps block the gene that converts sucrose into glucose and fructose, the sugar culprits that cause both acrylamide formation and browning. Through this process Jiang has created a numberof potato lines that produce very little acrylamide when cooked.

“Regular potato chips can have acrylamide levels up around 1,000 parts per billion,” says Jiang. “Ours are down around 150.” Jiang’s process, potentially of enormous use to the food industry, is now being patented by the Wisconsin Alumni Research Foundation.

But because they are genetically modified (GM), Jiang’s potatoes can’t be grown for consumption in the United States, where only a handful of GM crops have been approved and widely cultivated.

Jiang hopes that will change, and notes that GM versions of corn and soybeans, which are now added to many processed food items, contain DNA from other species. The extra DNA in his low-acrylamide potatoes, on the other hand, comes from the potato genome itself.

Down the line, especially if scientists confirm acrylamide’s link to human cancer, consumers may have to make a choice: accept a new GM crop or cut back on fries and chips.

Corn Connection

It’s no surprise that Mexico is a mecca for corn breeders. Not only is Mexico the center of the plant’s origin; the region also boasts the greatest natural diversity of maize grown on the planet, including wild relatives of maize. Moreover, the country is home to a wide range of tropical growing climates, from sea level to mid and high altitude.

“I can find climates that are representative of much of the world all within a half day’s drive,” says Kevin Pixley, who directs the genetic resources program at Mexico’s International Maize and Wheat Improvement Center (CIMMYT) and just completed several semesters as a professor of agronomy at CALS. During that period he retained a half-time appointment at CIMMYT, and he plans to continue cultivating a vibrant corn connection with CALS.

“CIMMYT scientists do not conduct basic research. But basic research, and the cutting-edge knowledge of basic researchers—for example in the areas of genomics, bio-informatics and nutrition—are instrumental to enable the application of recent scientific advances to benefit poor farmers,” says Pixley. “For UW scientists, participating in research projects with CIMMYT is an exciting opportunity to see their research reach farmers beyond Wisconsin and the United States, and to expand the impacts of their work and of UW.”

It was at CIMMYT that Pixley first met fellow corn breeder Bill Tracy, an agronomy professor and now CALS’ interim dean, who brought students to visit the CIMMYT headquarters in Texcoco.

Through Tracy, Pixley and other researchers, CALS’ corn work with Mexico continues to grow. And undergraduates get a taste of it. In August, for example, Tracy and Pixley, along with CALS nutritional science professor Sherry Tanumihardjo and agronomy professor Shawn Kaeppler, plan to once again hold a class for undergrads in partnership with CIMMYT. “Linking Agriculture and Nutrition in Mexico” will include a visit to the National Institute of Health in Mexico City and count toward a newly offered undergraduate certificate in global health.

Taking It Outside

IT’S A SCENE THAT FOR MOST PARENTS is frustratingly familiar:  Outside  blooms a perfect summer day, while inside kids drape themselves on furniture, calling out occasionally for snacks or to announce, “I’m bored!” The languor is broken only by trips to the cupboard or refrigerator. And then there is the bewitching power of “screen time,” a force few kids can resist. “TV, texting, Internet chatting, video gaming,” says physician Alexandra Adams, a professor of family medicine with the UW-Madison School of Medicine and Public Health (SMPH). “You name it, they’re doing it.”

As a childhood obesity expert, Adams knows another fact about today’s kids of summer: Many of them are at serious risk of packing on pounds. The children she treats at her practice in the UW Pediatric Fitness Clinic already struggle with weight gain and low fitness levels, and now 90 percent of them are coming back 5 to 10 pounds heavier after the three-month summer break, she says, without an associated increase in height. For young kids and teens, it’s a devastating amount to gain, especially since statistics say those excess pounds may never come off again. And her patients are hardly alone. According to the American Heart Association, one in three American children are now overweight or obese, putting them squarely on the path to adult obesity and at risk for adult diseases, including diabetes, heart disease, arthritis and kidney stones.

“We have kids in our clinic who are type 2 diabetics and hypertensive and on cholesterol medication in their early teens. They look like mini-adults,” Adams says. “They’re physiologically much older in their bodies than they should be. And that’s tragic.”

“There is no more ‘free range’ childhood,” says Dennis

These troubling trends have led doctors, nutritionists and health advocates to introduce a multitude of anti-obesity programs, including the national “Let’s Move!” campaign started by First Lady Michelle Obama last year. Educational initiatives, healthier school lunch programs, and kid-tailored fitness regimens are all being tried. But amid these carefully orchestrated interventions, a team of CALS and SMPH researchers is now wondering if we’ve missed an obvious part of the prescription, especially for children in summer.

With kids staying indoors in record numbers, what if we just got them to go outside?  This doesn’t mean shuttling them to weekly soccer games or other activities by car; kids today get plenty of that, says Sam Dennis, a CALS landscape architect who specializes in children’s environments and collaborates frequently with Adams. What Dennis has in mind are the outdoor experiences children used to have in the past—the type that 50- and 60-something adults describe when asked to explain how they played as children.

“They’ll say, ‘We didn’t have any equipment and we didn’t have organized teams. We would just go out into the woods and build forts or make mud pies,’” says Dennis, who collects these accounts to inform his design of children’s play spaces. “And they get very caught up and animated in telling stories of how they played in nature as kids.”

These children of 40 and 50 years ago not only played outside more; they were also only one-third as likely to be overweight as their counterparts today. Being outside obviously removes kids from the indoor temptations of snacking and screen time. Plus, research shows that kids who spend more time outdoors are also more likely to be physically active, Dennis says.

Yet like many seemingly simple solutions, this one, too, has a catch. Earlier generations of kids played outdoors and were slimmer for it not because they were somehow healthier or more capable of making good choices than children are today—even though some grownups like to think so.

“It’s not that we were so much smarter,” says SMPH physician and pediatrics professor Aaron Carrel, with a smile. Kids have always been kids. The difference was the environment.

“Obesogenic” is what the  Centers for Disease Control and Prevention calls the American landscape today, meaning it promotes unhealthy eating, a sedentary lifestyle, too many calories—and extra pounds. The more fattening aspects of our surroundings are easy to spot: a fast food hamburger and super-sized fries, for example. But what makes obesity so hard to prevent nowadays is that many things that foster weight gain have become part of our everyday lives, says Carrel. We take elevators instead of stairs, we drive instead of walk, we lift our garage doors with the press of a button. As a result, we probably expend 100 to 300 fewer calories each day than people did 30 years ago, while also taking in 100 to 300 more. And those added calories … well, they add up.

Nutrition for Life

ASSOCIATE PROFESSOR HUICHUAN LAI MS’90 PhD’94 BEGAN EXPLORING the link between nutrition and cystic fibrosis in 1994, when she spent a year working in UW-Madison’s pediatric pulmonary center. A registered dietitian trained in biostatistics, she has spent much of her career scouring epidemiological data for trends that explain how diet affects the health and longevity of children with the genetic disorder. Her work led the national Cystic Fibrosis Foundation in 2005 to rewrite its nutritional guidelines, a move that is contributing to a heartening trend toward better nutrition and increased life expectancy among CF patients.

What causes cystic fibrosis?

The basic defect is in the gene that encodes a transport protein for chloride. It affects almost all organs in the body, but the clinical manifestation is primarily in the lungs and in the digestive system. The classic presentation for undiagnosed CF is failure to thrive, meaning that kids don’t grow as they normally would. Because of the problem in the digestive system, they can’t absorb fat, and fat contains a lot of energy. The lung involvement does not manifest until a little bit later in life, and most patients end up dying from respiratory complications.

Nutrition treatments have lengthened survival dramatically. The median age of survival is beyond 40.

What can doctors do?

Because the lung disease is what causes mortality, the treatment now is really focused on that part of it. But there are many anecdotal observations, small studies, that show that if patients preserve good nutritional status the lung disease will progress more slowly. Over the last 10 years more and more emphasis has been placed on treating malnutrition, with the hope that you can slow down lung disease. And nutrition treatments have lengthened survival dramatically. The median age of survival is beyond 40 now. Three decades ago it used to be less than 10.

How is nutritional status measured in these patients?

It’s important to define optimal nutritional status in CF patients because nutrition has such a big impact on lung disease, quality of life and survival, and that’s what my research focuses on.
So the Cystic Fibrosis Foundation publishes clinical practice guidelines—the first one was done in 1992, and then it was updated in 2002 and again in 2005. The guidelines traditionally have been based on how close a patient’s weight is to an ideal standard. So when a patient comes to the clinic, doctors will try to calculate the patient’s ideal weight, and then they will take their actual weight as a percentage of ideal weight. If the result is above 90 percent, they say, “That’s fine. Let’s keep watching.” If it’s below 90 percent, they do something about it. One of my major contributions to the field is that I proved this percentage of ideal body weight guideline is faulty. It’s only correct for children of average stature.

What was wrong with it?

At the extremes (of height), the ideal body weights are wrong. If the patient is short, for instance, the ideal weight is underestimated. So when you do the calculation for a short child, a doctor is more likely to think a child is fine, when in fact he is too thin.

How did you figure this out?

I didn’t just discover it. I was motivated by questions coming from the clinic. I work with dietitians and pulmonologists a lot, and this question was brought by a dietitian who was using this index in the clinic. She had calculated the ideal weight for a child who was particularly short, and it just didn’t seem right to her. She said, “This child is not supposed to be at this weight. It would be too low.”
I also heard about problems with tall patients, where the dietitian would say, “I can’t increase his weight to that level, I think it’s way too high. Why is that the standard?” It’s not only frustrating. It doesn’t make sense to them.
So these comments motivated me to look into whether there was anything wrong with the definition of this parameter. That is how I got started.

Christian Abnet

Abnet explores the nutritional causes of cancer as an investigator with the National Cancer Institute, where he’s investigating whether factors such as diet and poor oral health raise the risk of developing esophageal and gastric cancer. Much of his work focuses on high-risk populations, particularly people in developing countries. He has collaborated with epidemiologists, clinicians, statisticians and lab scientists in China, Iran, Kenya, Ireland, Brazil and the United States, among other places.