A conversation with Dr. Marion Nestle who talks about the subject of your doctor and nutrition.
This issue's column is an edited version of a conversation I had with Marion Nestle, an associate dean and lecturer in medicine and biochemistry at the University of California School of Medicine in San Francisco, on what you need to know about your doctor and nutrition. Dr. Nestle teaches nutrition to health science students, as well as to resident physicians, and she coordinates nutrition education within the School of Medicine. A Ph.D. in molecular biology from the University of California at Berkeley, Dr. Nestle is also a contributing editor of Medical Self-Care.
Many people say that medical schools generally ignore the area of nutrition science. Do you agree?
Yes . . . and even when the subject is included in a curriculum, the classes tend to be inadequate.
Well, first of all, many people who teach biochemistry, physiology, or other "hard" sciences are a bit contemptuous of nutrition . . . they don't consider it a real science. After all, because of the field's relative newness, nutrition researchers don't have the huge body of well-controlled corroborating data that most other sciences can call upon . . . so it's often difficult to make a convincing scientific argument for the importance of diet in medicine.
Is there any other reason why many medical students receive little or no practical nutrition training?
Probably the biggest reason is that we all—doctors and laypersons alike—tend to view medicine as a curative, rather than a preventive, science. Most people see a physician only when they're sick and need immediate help. They don't come to get advice on nutrition . . . they come to get treated for an illness.
Recently, I saw a quote by Harvard nutritionist jean Mayer, who said—in effect—that the average doctor knows little more about nutrition than the average non-physician.
Well, perhaps that's a bit unfair to physicians . . . most doctors are fairly well trained in such technical subjects as carbohydrate biochemistry and metabolic functions. But they generally don't know how to apply that textbook knowledge in a way that's useful to people. In other words, they fail to relate that basic information to their patients' actual eating habits and diets. They need to understand, for example, the importance of the differences between foods that contain starch and those that contain sugar. When a patient asks a question concerning nutrition—about, for instance, which foods are and are not beneficial to that particular individual—the doc tor should be able to provide a practical, meaningful answer.
Plus, since proper diet plays an important preventive and curative role in many diseases, a physician should be cognizant of what is known—and not known—about dietary approaches to dealing with common chronic illnesses such as heart disease, obesity, diabetes, and high blood pressure. Nutritionists and dieticians are especially trained to counsel patients on eating habits, so doctors should know when and how to refer patients to such experts.
Isn't recommending a balanced diet a commonsense first step?
Absolutely. The evidence is increasingly clear that the dietary goals and guidelines established by the McGovern committee and the U.S. Department of Agriculture represent a unified approach to both normal—that is, preventive—and therapeutic diets. Generally, the same food regimen that's best for health is also the one to recommend to people with heart disease, diabetes, or obesity.
What, exactly, is this "unified" dietary approach?
It's simple enough: Eat unprocessed foods that are high in complex carbohydrates and in fiber . . . such as fruits, vegetables, and whole grain cereals. Go easy on the fat, salt, and sugar. And eat a wide range of foods. Variety is important because foods differ in the kinds and amounts of nutrients they contain, so consuming an assortment of comestibles—and I'm speaking here of non-junk foods, with high nutrient densities—can help a person be sure that he or she is getting all of the necessary nutrients.
What do you mean when you say "high nutrient density"?
That's just nutritionists' jargon for a food that's rich in nutrients and low in calories. Junk foods, of course, are just the reverse.
You mentioned to me once that you require your medical students to record a 24-hour diet inventory. How useful is such a practice . . . and what's involved?
Well, the process is a bit tedious, but it teaches a great deal about the importance of watching what you ingest. You simply list everything you eat and drink in one day, and afterwards look up the nutrients present in each edible in standard food composition tables. Then add up the daily totals, and compare those figures with nutritional guidelines such as the U.S. Recommended Daily Allowances. It's fascinating to find out which nutrients are present in common foods. Many people, for example, are surprised to find how much protein is in vegetables.
What books would you recommend for those who want to do a one-day, diet inventory?
Composition of Foods, and Laurel's Kitchen. Composition is the standard source for nutritional information. Laurel', Kitchen is a vegetarian cookbook with a long and truly excellent section on the principle, of nutrition . . . and the text is accompanied by very handy food-composition tables. I just wish that the book included more information for people who eat meat!
Do you have any advice on how to shop for groceries . . . and how to determine which foods are nourishing and which are not?
Yes. If you buy food in a supermarket try to avoid the center aisles. All of the real, unprocessed foods—the vegetables, fruits, meats, and dairy products—are generally located around the periphery of the store. But the low-nutrient junk foods are usually kept in the center aisles, so stagy away from those areas. And by all means, read the products' labels. The information on such wrappers isn't always complete, but at least it will tell you which products do and do not contain undesirable ingredients such as sugar, salt, fats, and additives.
One final question: Have your own eating habits changed as you've learned more about nutrition?
Yes, but it has been a gradual process. For example, I'm still not a strict vegetarian, but my family's diet has certainly moved increasingly in that direction. And we haven't used salt in a long time. Generally, I simply try to follow the same basic advice I give to my students and others: Eat a variety of whole, unprocessed foods in moderation. And above all, enjoy your meals . . . a healthful diet doesn't have to be boring!
EDITOR'S NOTE: The U.S. Department of Agriculture's Composition of Foods (Agricultural Handbook Number 8) is available for $7.00 from the Superintendent of Documents, U.S. Government Printing Office, Dept. TMEN, Washington, D.C. Order Stock No. 001-00000768-8. Laurel's Kitchen: A Handbook of Vegetarian Cookery and Nutrition by Laurel Robertson, Carol Flinders, and Bronwen Godfrey can be purchased at most bookstores in paperback (Bantam, $4.50) and in hard cover (Nilgiri Press, $18).
Dr. Tom Ferguson's quarterly journal, Medical Self-Care, is available for $15 per year from Medical Self-Care, Dept. TMEN, Inverness, California. A sample issue costs $4.00. Dr. Ferguson's book, also titled Medical Self-Care, can be ordered — for $8.95 plus 95¢ shipping and handling — from MOTHER's Bookshelf® Hendersonville, North Carolina.