Forty years of the Nurses' Health Study: An evidence goldmine with a long-lasting legacy

It started in 1976 as an investigation into the potential health consequences of oral contraceptives, but the long-running Nurses' Health Study has yielded increasingly greater benefits to scientific knowledge of health and disease, according to a paper published today in the journal Public Health Research & Practice.

The Perspective paper by Dr. Graham Colditz, the Study's Principal Investigator from 2000-2006, says researchers have used information gathered from the Study's more than 275,000 participants from right across the US to make many advances, including helping expand the field of risk prediction in cancer.

"The Study has guided recommendations from the US Surgeon General in areas such as the adverse health effects of smoking, and resulted in changes to regulation, such as in the area of transfat and its effect on heart disease and diabetes," said Dr. Colditz, who is currently Chief of the Division of Public Health Sciences and the Niess-Gain Professor of Surgery at the Washington University School of Medicine in St. Louis, US.

"The Study is now working with a third generation of American women. Much has changed in the field of epidemiology in the past 40 years and we have had to adapt to respond to emerging public health issues.

"For example, wider use of pathology samples to understand the causes of disease led us to conduct a series of biomarker studies to better understand the connections between lifestyle and cancer. One finding to emerge from that work was that breastfeeding is linked to lower rates of certain types of breast cancer."

Other major findings to have emerged from the Study include:

• More years of rotating night shift work is linked to higher risk of coronary heart disease, breast cancer and colorectal cancer
• Improving the diet lowers the risk for cardiovascular disease
• Higher levels of physical activity reduce the risk of cancer recurring in women who have had breast or colorectal cancer
• There is no association between silicone breast implants and connective tissue disease.

The latest issue of Public Health Research & Practice has a special focus on cohort studies, and also examines the contributions of other major longitudinal cohort studies such as the Sax Institute's 45 and Up Study examining healthy ageing in more than a quarter of a million Australians.