Is salt bad for your health? Should everyone cut back? Does it pose a risk only for people with high blood pressure? Should policymakers regulate the amount of salt in our food? Do we have the evidence we need to support such actions? Will we ever have it?
Debate has raged over these questions since the late 1960s. In a new review of half century of studies, recommendations, meta-analyses, federal policies, and reports in the popular press, Mailman School professors Ronald Bayer, PhD and Sandro Galea, MD, DrPH, along with Sociomedical Sciences doctoral student and journalist David Johns serve up a provocative new analysis of the case, such as it is, for reducing dietary salt. They also raise fresh and urgent questions about how to formulate policy when scientific evidence is ambiguous and contested.
The article is published in the December issue of Health Affairs. See abstract.
Some key moments in the salt debate:
“What’s striking about the salt debate,” write the authors, “is that the combatants cannot be neatly divided between the respected advocates of a mainstream position and a band of marginal dissidents. Respected scientists have found themselves on both sides of the divide.”
The salt saga raises key issues about how to formulate “evidence-based” policy, says Dr. Bayer, an ethicist and professor of Sociomedical Sciences who co-directs the School’s Center on the History and Ethics of Public Health. “We concluded that it is a mistake for policymakers to pretend that the evidence is clearer than it truly is. Concealing scientific uncertainty does not serve science or the public.”
"We were interested in exploring the gap between the certitude of our public health action and the confidence of the science. Understanding the reasons for the difference between the two may help guide us to more informed evidence-based practice", says Dr. Galea, Gelman Professor and Chair of the School’s Department of Epidemiology.
In fact, the authors believe that the commonplace view that research evidence can be smoothly translated into action is overly simplistic. They call instead for a more nuanced and transparent weighing of evidence, costs, likely benefits, and possible unintended consequences.
December 7, 2012