[7] His work with the Human Population Laboratory in the Alameda County Study established the connection between mortality and lifestyle issues like exercise, diet, sleep, smoking, and alcohol.
[12][13] While studying to be a psychiatrist in medical school, he worked for a summer in the Fergus Falls Minnesota State Hospital for the Insane.
After Breslow returned to medical school for his senior year, he shared his feelings with a friend and faculty member who introduced him to Gaylord Anderson, a new professor of public health.
[14] During World War II Breslow served in the United States Army as a public health officer on a ship sent to the Pacific.
A voluntary initiative targeting hospitals, the registry is credited with educating doctors, increasing their skills, and improving patient care.
[2] From 1960-1965, Breslow served as Chief of Preventive Medicine Services of the California State Department of Public Health.
[12][7] Ronald Reagan, then Governor of California, chose to replace Breslow, a Democrat, due to “philosophical differences” over cuts in medical care for the poor.
[17][31] One of his most famous works is with the Human Population Laboratory in Alameda County where he identified a correlation between various lifestyle issues and mortality.
[7] Between 1965 and 1985, Breslow tracked approximately 7,000 adults in a longitudinal study that examined the relationship between mortality rates, health status, social networks, and potentially relevant personal characteristics and behaviors.
Degree of social connectedness was found to be a major predictor of mortality risk, as those with more connections to family, friends, and community were likely to live longer.
Breslow suggests that a third era would focus on health as opposed to illness, and emphasize the means of promoting well-being and leading satisfying lives.
[36] Breslow believed that health should be regarded as a resource for everyday life, as opposed to just a way to prevent disease.
[7] In an obituary written by one of his former protégées it says, "I was one of Lester's preventative medicine residents 15 years ago…Having had an opportunity to observe him engage with 'paupers' and 'kings,' I can attest to his treatment of all with respect and appreciation for their humanity, abilities, and contributions.