Public opinion versus public interest: lessons for science policy

Yesterday's Politico had an interesting article suggesting "A lesson for Obama from the other Roosevelt." Bush White House aide Daniel M. Price extracted a quote of Theodore Roosevelt from historian Edmund Morris' TR biography, Theodore Rex. Roosevelt responded to a journalist who suggested that popular opinion favored nationalizing American railroads instead of Roosevelt's tack of increasing regulation; TR said:

Here is the thing you must bear in mind. I do not represent public opinion: I represent the public. There is a wide difference between the two, between the real interests of the public and the public's opinion of those interests. I must represent not the excited opinion [of some], but the real interests of the whole people.

A parallel leapt to mind, probably because I spent yesterday in a meeting with medical scientists and nutrition experts. Many public health nutrition groups and the federal government have used "expert consensus" as an argument to support a public policy of encouraging everyone to eat less salt. Expert opinion mirrors public opinion in this case; the federal government has spent tens if not hundreds of millions of dollars "educating" the public and public opinion is that dietary salt is consumed in "excess" amounts. As in TR's apt distinction, however, there is a "wide difference between this expert/public opinion and the public's true interest.

The public cares about improving health. It cares about the quality of the evidence underlying public policy. And for good reason: physiology trumps expert opinion. Whether the experts get it right or not, the body is going to do "its thing" by responding to changing conditions. So it is with the science concerning dietary salt.

While some groups prescribe salt reduction, the inventors of "evidence-based medicine," the Cochrane Collaboration, finds insufficient evidence to recommend a population-wide lowering of dietary salt. The Cochrane Review, "Advice to reduce dietary salt for prevention of cardiovascular disease," concluded: "There was not enough information to assess the effect of these changes in salt intake on health or deaths."

Policy should reflect the needs of the public, not public opinion. However that may play out in President Obama's efforts to stabilize the U.S. financial system, it's a sound prescription for healthy public nutrition policy.