Advisor Spotlight: Walter Willett, MD, DrPH

 

Dr. Walter Willett is Chair of the Department of Nutrition, Harvard School of Public Health and Fredrick John Stare Professor of Epidemiology and Nutrition. He studied food science at Michigan State University, completed his medical degree at University of Michigan Medical School, then an M.P.H. and DrPH in Epidemiology at Harvard School of Public Health. He has been Chair of the Department of Nutrition since 1991.

 

In looking back at his interest in nutrition and health, Dr. Willett recalls his early experience in a 4H vegetable  growing club and a contest he won in high school. "I received the Michigan National Junior Vegetable Growers Association award for grading vegetables and identifying pests that effect potatoes, carrots, and other crops." That was only the beginning of what would become Dr. Willett's distinguished career in nutrition and health.

Prior to his passion and commitment to professional research Dr. Willett practiced internal medicine in a neighborhood health center in East Boston.  Frustrated with the realities of chronic problems such as diabetes, hypertension, and congestive heart failure, Dr. Willett felt compelled to pursue research. "I was helping people manage and live with their health issues but realized I wanted to understand the origins of those issues and help to prevent them. "

Pursuit of Empirical Data and Creation of a Standard

 

Dr. Willett's first project, and subsequent paper (Willett WC, Foulke RA, Robson JRK, Block WD, Perlman LV.  Health and nutrition in  Michigan Indians.  Mich Med 1970;69:305-11) documented a survey of the health and nutrition of Native Americans living in the upper peninsula of Michigan. "With 50% of adults dealing with diabetes, I was impressed that we could learn a lot about their diet using a standardized questionnaire. These people were living from U. S. D. A. surplus commodities because they had limited means of food production. Decades later, we have the data documenting that those foods were almost the perfect fuel for diabetes, particularly in a susceptible population."

 

Dr. Willett explains that "in the late 1970's there was a growing understanding that nutrition was likely to play a major role in the development of cardiovascular disease and cancer. The public was being given strong advice about what to eat, for example margarine, and what not to eat, for example eggs. Yet there was no direct evidence to support those recommendations; this was mainly based on educated guesses.  An empirical body of data was needed to identify dietary risk factors for disease. For example, studies were needed to examine the relation between eating eggs and heart disease. Such basic recommendations should have evidence to support them.  As it has turned out, egg consumption, at least up to one egg per day, does not appreciably increase risk of heart disease in healthy people. Another example would be the conventional wisdom, in 1977, that smoking was not a risk for heart disease in women; of course we now know that it is a very major risk factor!"

 

The pursuit and achievement of such necessary and useful information has been Dr. Willett's mission. In 1989 Dr. Willett established The Nurses' Health Study II (an expansion of the original Nurses' Health Study established in 1976 by Dr. Frank Speizer). These studies are among the largest prospective investigations into the risk factors for major chronic diseases in women. The studies have grown to include a team of clinicians, epidemiologists and statisticians at the Channing Laboratory along with collaborating investigators and consultants in the surrounding medical community of the Harvard Medical School, Harvard School of Public Health, Brigham and Women's Hospital, Dana Farber Cancer Institute, Boston Children's Hospital and Beth Israel Hospital.

 

Since 1980, The Nurses' Health Study has included as a primary objective the investigation of dietary factors, using epidemiologic approaches, in the cause and prevention of cardiovascular disease, cancer, and other important conditions. Fundamental to this work has been the development of methods to measure dietary intake in large populations, devoting substantial ongoing effort to the creation and refinement of standardized dietary questionnaires that can be completed repeatedly by subjects over a number of years. Such questionnaires have now been demonstrated to provide reasonably accurate assessments of a wide spectrum of dietary factors. In addition, Dr. Willett and his team continue to work on the development and evaluation of biological markers of dietary intake, particularly using plasma and toenail samples. These biological indicators are primarily utilized in nested case-control studies using the large specimen banks collected prospectively as part of their ongoing studies. Dietary data have been collected from all of these populations, including eight cycles in the Nurses' Health Study. Also evaluated are the relationships between the use of exogenous hormones in the form of oral contraceptives and post-menopausal estrogens to risks of breast cancer and other diseases, as well as other lifestyle factors, such as physical activity, in relation to occurrence of important diseases.

 

The "Trans-Fat Alarmist"

 

In 1978 Dr. Willett noted just how worrisome trans fats are. "The food industry was taking natural fatty acids, which play many critical biological functions, and changing the structure of the molecule, and these were being consumed in very large amounts.  Almost surely this change in structure would affect function, and probably not for the better." Being the first to document in a prospective study that trans fats are associated with risk of heart disease, Dr. Willett was labeled as the "Trans-Fat Alarmist" by the Wall Street Journal, which was dismissive of their harms. "Fifteen years ago," he says, "trans fats were not on the radar screen of nutritionists. Food processing makes a fundamental impact on our diets having important biological effects that must be considered."

 

As a result of continuous warnings by Dr. Willett and other researchers, cities have in fact begun to ban trans fats. As Dr. Willett notes, "even fast food has changed in a major way over the last two years in response to such research. Positive change and better health is what truly matters." 

Future Hopes

 

Dr. Willett's future hopes include more work on understanding breast cancer prevention, particularly factors that operate early in life. He is also concerned about the extent of overweight and obesity in America. "It's a huge health problem," he exclaims. "The evidence is overwhelmingly clear. 'Beauty' is a distraction because it isn't just about how we look, which is in the eye of the beholder, but how we are, or are not, healthy. We need to solve the problem. In parts of the country life expectancy is declining, which is very troublesome. Better lifestyle and diet are key. Aggressive advertising to children of damaging food and beverages, along with inactivity in and after school, etc. are significant risk factors." Dr. Willett's concern for health eduction and healthy living to be accessible to all people is evident. "Some parts of the population are eating better and exercising more, and they are living longer and more functional lives.However, a large part of the population, probably the majority, are eating less well and becoming increasingly overweight and unhealthy; the chasm is getting wider. The challenge: to create an environment and culture where active living and healthy eating are the norm. Fortunately, the need for prevention is becoming increasingly apparent, whether the concern is the epidemic of obesity and diabetes, skyrocketing costs of healthcare, or global warming. Physicians can play a key role in this transition, both by giving their patients the best personal guidance possible and by being community leaders in creating the environment to support health-promoting changes in lifestyle."

 

 

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