Starting in the mid-20th century, the primary causes of death worldwide shifted from infections to chronic conditions, such as heart disease and cancer. The School has meticulously documented this change, standing at the forefront of both basic and applied research. Its discoveries in nutrition, exercise, and other individual risk factors have reconfigured the public health landscape.
The Nurses’ Health Study I, a collaboration begun in 1976 among School scientists and researchers at Brigham and Women’s Hospital and the Channing Laboratory, was the first of a series of prospective cohort investigations, now among the largest and oldest in the world. The study produced a lengthy list of surprising findings. Among these: that a high-fat diet increases colon cancer risk but not breast cancer risk; that weight gain after adolescence raises death rates in midlife; and that light smoking more than doubles the risk of heart disease. The Physicians’ Health Study showed that an aspirin a day reduces the risk of heart attack.
The School’s Department of Nutrition, founded in 1942, was the first such department in a medical or public health school in the world. Its groundbreaking research includes work on the health benefits and hazards of proteins and fats; the components of a well-balanced diet; and clinical aspects of obesity. School scientists created the first animal model for hypercholesterolemia and demonstrated the protective nature of HDL cholesterol and the blood vessel-damaging potential of LDL cholesterol.
In the 1970s, School scientists helped map the government’s Dietary Guidelines for Americans; decades later, they proposed an alternative Healthy Eating Pyramid based on the Mediterranean diet and including recommendations for daily exercise and weight control. In 2006, when the U.S. Food and Drug Administration ordered that nutrition labels for packaged foods list all harmful trans fatty acids, it signified a victory for School scientists, led by Walter Willett. A vigorous public health advocate, Willett not only amassed evidence that these solid fats raise the risk of coronary artery disease, type 2 diabetes, and other ills, but also waged a campaign to label and ultimately eliminate the ingredient from manufactured food products and restaurant meals.
Established in 1988, the Center for Health Communication has used entertainment media and mass communication to shift social norms in healthier directions. Among its innovations, it worked with Hollywood to incorporate the Swedish-originated designated-driver concept into entertainment programming, which decreased alcohol-related traffic crashes. So successful were the School’s efforts that the Random House Webster’s College Dictionary (1991 edition) added “designated driver” to the American lexicon.
In a similar vein, School faculty have led the charge for worldwide tobacco control, providing the scientific expertise to convince nations in Europe and Asia to pass smoking bans for public places. In a pair of 2008 studies, School investigators revealed a deliberate strategy among tobacco companies to recruit and addict young smokers by manipulating menthol content and by heavily advertising in places that cater to youth.
In 2008, School researchers published the largest and longest-running study to estimate the impact of a combination of lifestyle factors on mortality. The study concluded that not smoking, maintaining a healthy weight, regular physical activity, and a nutritious diet dramatically lowered the risk of dying from all causes during the 24 years of the study. In 2009, resolving a long-simmering scientific and popular debate, School investigators found that diets that reduced calories led to weight loss, regardless of the proportion of carbohydrates, protein, or fat.