University of Minnesota

Alameda County Study

Study Category: The Cohort Studies (1947-1972)
Year Begun: 1964
Location: Alameda, California
Principal Investigator: Breslow, Lester
External Resource: View URL


The Alameda County Study was designed to investigate normal daily routines and social-support factors to determine which might be risk factors for poor health and mortality in a real community.


In 1965, a probability sample of the population of Alameda County, California was invited to participate in a study on health status, social networks, and other personal characteristics. The follow-up group contained 6,928 participants who completed questionnaires and were followed at intervals for up to 20 years after the initial investigation.


The study found seven risk factors—or health practices—associated with poor physical health and excess mortality: drinking excessive amounts of alcohol, smoking cigarettes, being obese, sleeping fewer or more than seven to eight hours per night, being physically inactive, eating between meals, and not eating breakfast. Sex differences were seen in weight, alcohol consumption, and sleeping habits.


The Alameda County Study was the first to look at social networks as determinants of mortality. The results from the study helped to quantify the new concept of health created by the World Health Organization, which defined health as a state of “physical, mental and social well-being.” Researchers applied a numerical value to health characteristics and discerned which of them were associated with reduced health status. (FB/HB)


Breslow, L., and N. Breslow, 1993. Health practices and disability: Some evidence from Alameda County. Preventive Medicine 22:86-95.

Belloc, N.B., L. Breslow, 1972. Relationship of Physical Health Status and Health Practices. Preventive Medicine vol.1: 409-421.

Idler, E. L., Y. Benyamni, 1997. Self-Rated Health and Mortality: A Review of Twenty-Seven Community Studies. Journal of Health and Social Behavior vol. 38(1): 21-37.