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Northwestern Medical School's Robert Kushner, left, and Linda Van Horn are committed to curriculum improvements regarding the impact of nutrition on health.

(Photo by Janet Mesic-Mackie)

Tired of being tired every day, L.J. paid a visit late last year to Northwestern Memorial Hospital's weight management clinic. Suspecting her obesity as the reason for her fatigue, the 42-year-old hospital worker was prepared to make some significant changes in her diet, which primarily consisted of lots of fast food and no fruits and vegetables.

What she didn't suspect was a diagnosis of adult-onset diabetes, a chronic condition that correlates highly with obesity.

Determined to take control of her health, L.J. has overhauled her eating habits, takes part in daily exercise and has dropped about 30 pounds so far, changes that have prevented her from having to go on medication. As an added benefit, "she feels good about herself," says her physician, Robert Kushner, professor of internal medicine at Northwestern University Medical School.

L.J. is hardly alone in her struggle to control her fast-food eating habits and expanding waistline, not to mention the attendant chronic diseases that can result from a diet high in saturated fat and sugar. In fact, according to recent government statistics, more than half of all Americans today are overweight, or at least 10 percent above a person's healthy weight range. Even more worrisome, one-third of the population is now considered obese, or 30 percent above that range.

Bringing nutrition into the mainstream
L.J., however, may be the recipient of a cutting-edge movement to integrate nutrition -- with its far-reaching effects on health and disease prevention -- into the mainstream of medical education, research and patient care.

That movement has been spurred at the Medical School in part by new sources of federal support. Last fall, Northwestern was one of 10 medical schools in the country to receive a $750,000 Nutrition Academic Award from the National Heart, Lung and Blood Institute, a branch of the National Institutes of Health (an additional 10 schools will be funded beginning in the year 2000). The prestigious five-year award, conferred for the first time, was granted to facilities that could demonstrate their commitment and ability to provide nutrition education in their medical school, says Linda Van Horn, professor of preventive medicine at Northwestern and principal investigator on the project.

"This is a tremendous testimony to the interest, awareness and collective scientific agreement that nutrition is important in the prevention and treatment of disease," says Van Horn. Along with Kushner, the co-principal investigator, other collaborators include Marian Fitzgibbon, associate professor of psychiatry and behavioral science; William McGaghie (SESP71, GSESP73), professor of medical education; Alvin Telser, associate professor of cell and molecular biology; Jay Prystowsky (GME89), assistant professor of surgery and director of the surgical clerkship; Arline McDonald, adjunct assistant professor in preventive medicine; Julie Scheier, director of nutrition services at Northwestern Memorial Hospital; and Eileen Peters, a nutritionist who will serve as nutrition coordinator.

Everyone involved will collaborate on curriculum modification to incorporate nutrition education throughout the four years of medical school. From McDonald, students will gain a deeper understanding of principles in nutritional biochemistry as they relate to disease. In their clinical years, they will develop skills in assessing patients' nutritional status and meeting their needs with the appropriate dietary approach. At the same time, medical residents and faculty members will receive training on practicing nutritionally sound treatment and disease prevention. In addition to the work of Kushner and Van Horn, Prystowsky, McDonald, Scheier and dietitian Bobbie McCarthy are collaborating on a nutritional focus in a surgical clerkship for third-year medical students that began this summer.

Making nutrition relevant to students
Kushner, a medical doctor who holds a graduate degree in nutrition, is quick to concede that medical students' current awareness of the complex interplay between food intake and a patient's health is limited.

"It's poor -- that's the simplest way to say it," Kushner says. "Medical students are inundated with a very crowded curriculum that focuses on molecular biology and genetics and pathophysiology and disease processes. All of this has displaced how to talk to patients, how to get them to change their behavior and how to make meaningful changes in their choice of food."

Third-year medical student Rishi Agrawal agrees. "A lot of students do find that nutrition is an important topic, but there are so many other things to worry about that it becomes something that's put on the back burner," he says. Nutritional knowledge, attitude and behavior relating to students' own diets are also being assessed over the course of the project, locally and nationally. The curriculum moves from the basic fundamentals and concepts of nutrition to their clinical applications. Underlying this introduction is the message that nutrition matters, a concept that was staunchly supported by the late Robert Winter (GM71), associate dean for medical education, during the Medical School curricular reform initiated several years ago. This commitment continues to be endorsed by Raymond Curry (GME85), executive associate dean for education, and the current curriculum committee.

"One [part] is what you need to ask, the other is how to interpret it," Kushner says. A physician nutritionally evaluating a patient with, say, hypertension should be asking specific questions about alcohol consumption, salt, and fruit and vegetable intake. "It's not just memorizing the questions, but understanding the nutritional issues related to that person's risk."

In the third year, as students begin rotating through their clinical clerkships, they will learn about the impact of nutrition on chronic diseases, as well as the role of nutritional therapeutics, such as calcium supplements for women with osteoporosis. Depending on the electives chosen by fourth-year students, they will receive more in-depth education on specific topics, such as the role of nutrition in influencing cholesterol levels and its relation to heart disease.

Power of communication
Kushner believes the emphasis that medical students will receive about the relationship of nutrition and health will help create doctors who are able to make more precise diagnoses and communicate more easily with their patients.

"If a patient comes to see a physician with gastrointestinal complaints and if the doctor doesn't understand the role of lactose intolerance, he or she can lead that person into diagnostic tests that may not help them," he says.

Likewise, talking to patients about their food habits, likes and dislikes "is a message that this doc is interested and cares about them," which can improve the range of communication between a physician and patient.

Agrawal was impressed by the level of communication he observed between Kushner and his patients during a nutrition internship last summer.

"It was nice to see those principles used and reinforced," he says. Even though first-year medical students are taught communication skills to help patients modify their behavior, "what you learn ideally to do with communications is not often done," Agrawal says. Because those skills were adapted to the clinic setting, "patients were more engaged than they might have been if the doctor just told them to lose weight."

Physicians whose medical education did not teach them to help patients manage their weight may get a boost from a separate grant from the Weight Watchers Foundation. The grant, awarded to the Medical School last January, will support a curriculum for medical residents to augment their knowledge about obesity and to learn more about counseling overweight patients.

Right now, residents typically view the latter task as "daunting," says Kushner, "a challenge that would be extremely difficult to succeed in." It is hoped that they will gain some practical insights into the counseling issue through role-playing and videocassettes. Residents also will learn that their goal "is not to cure [patients'] illness ... but to help patients help themselves." After testing the curriculum at Northwestern, grant sponsors hope to export it to other medical schools.

Diet and disease link
Clearly, both physicians and patients face major challenges in putting what each of them knows about nutrition into everyday practice. But major questions remain about the precise role that diet plays in the development of certain diseases. Breast cancer provides a good example.

In studies funded by the National Cancer Institute, Van Horn and colleague Peter Gann, associate professor in preventive medicine, are examining the impact of diet on potential identifiers, called biomarkers, that could indicate the increased chances of getting breast cancer. "We are desperately in search of a biomarker," explains Van Horn, "that will serve as a legitimate risk factor for evaluating someone's risk of breast cancer. Then, we can try to find an effective intervention to help reduce that risk."

The analogy she uses is high-serum blood cholesterol levels and their well-known link to cardiovascular disease. While the role of hormones has long been suspected in the origin of breast cancer, scientists don't know specifically which hormones might be responsible or where to look for the clearest indication of elevated risk, if any.

In one Northwestern study, to be completed by next year, 200 healthy, premenopausal women are following a diet low in fat and high in fruits and vegetables for one year. Each week, the participants, whom Van Horn describes as "incredible in terms of their commitment," report their dietary intake and provide samples of their blood, urine, saliva and breast fluid. After one year, study participants have added soy powder supplements to their diet. Half contain isoflavones, thought to influence hormone levels, and half have no isoflavones. At the conclusion of that phase, researchers will begin to compile the results.

As a visiting scientist this year at the International Agency for Research on Cancer in Lyon, France, Gann is focusing on the dietary, hormonal and genetic factors that determine the risk of breast or prostate cancer. He and his colleagues are planning the first studies of participants in the European Prospective Investigation into Cancer (EPIC) cohort. The study, which has enrolled more than 450,000 individuals from nine countries, is the largest ever assembled for epidemiological studies on cancer and draws from a diet-diverse population ranging from Sicily to northern Sweden.

"In EPIC, we will be relating hormonal patterns and diet patterns to each other and to cancer risk," Gann explains. "The recent leaps in gene sequencing technology add a new dimension -- the ability to look at how common inherited variations in certain genes might affect dietary or hormonal pathways related to cancer risk."

Searching for answers
While the media's tendency to oversimplify or exaggerate research findings contributes to the general public's confusion about the link between diet and disease, even the experts admit their occasional bewilderment over some findings.

A study published in a February issue of the Journal of the American Medical Association concluded that women who follow a low-fat diet got little protection against breast cancer. Despite the surprising findings, the Harvard researchers who followed more than 88,000 women over a 14-year period still endorsed a low-fat diet because of its proven ability to reduce the risk of heart disease.

"The findings were certainly puzzling to me because of the information that continues to support the value of a diet rich in fruits and vegetables," says Van Horn, who believes there may be a cause-and-effect relationship between a high-fat diet, especially during puberty and adolescence, and a predisposition to breast cancer. Having conducted many studies whose results depend on the accuracy of people's recollection of their food intake, she adds, "I am very aware of the limits of the dietary assessment methodology used in many epidemiological studies. Our goal is to collect the most accurate and detailed dietary data possible."

Gann cautions against dismissing the findings, suspecting instead that in determining the role of dietary fat and its relation to breast cancer, "fat might only be a small part of the picture. People who eat a low-fat diet have a dietary pattern that differs in many ways," he observes. "We shouldn't just think about fat in isolation."

In any event, the findings have served as additional motivation for Van Horn. "While it is certainly puzzling, it simply causes me as an investigator to redouble my efforts in collecting accurate dietary data and looking more specifically at these biomarkers.

"With the new focus on medical nutrition education, more attention is likely to be paid to these questions in the near future among our students and faculty."

Cathy Tokarski is an editor at American Medical News, a weekly newspaper published by the American Medical Association.