Salt War Opponents Unite In Call For Randomized Trial In Prisons

The opposing camps in the salt wars don’t agree on much, but they have now found common ground in their belief that the only way to settle the salt question is with a large randomized controlled trial. Further, they now agree that it would be nearly impossible to perform such a trial in the real world. Instead, they now say, the trial would almost certainly need to be performed in a highly controlled environment like a prison.

The scientific and medical community is deeply divided over dietary salt recommendations. Current guidelines recommend drastic reductions in dietary sodium, from the current intake of about 3,500 mg/day in the American diet to lower than 2,300 mg/d. Guidelines from the American Heart Association and the Institute of Medicine (now the National Academy of Medicine) enjoy support from a majority of experts. But a significant minority of experts has expressed strong opposition to these recommendations. The proponents of lower sodium intake base their position on the fact that lowering sodium leads to lower blood pressure levels; health benefits, they argue, will inevitably follow from this drop in blood pressure. The critics agree that reducing sodium leads to lower blood pressure but that the benefits and also any potential harms of population-wide reductions in sodium have never been adequately tested in a rigorous fashion.

In May 2017 six leading figures in the salt wars came together in Jackson, Mississippi to try to find common ground. They included prominent supporters of salt reduction, like Daniel Jones, a former president of the American Heart Association, and equally prominent critics, like David McCarron. Now the six have joined forces, and recruited two neutral clinical trial experts, to advocate for a large sodium outcomes clinical trial. In a paper published in Hypertension the authors, ask “Can We End the Salt Wars With a Randomized Clinical Trial in a Controlled Environment?”

At their meeting, they report, “the group concluded that differences of opinion on existing data could only be resolved with a randomized clinical trial evaluating the impact of dietary sodium on hard clinical outcomes, including death, stroke, and myocardial infarction.”

A key recommendation of the group was that to be successful the trial would need to be performed in a controlled environment. The group considered several options— including military personnel, nursing homes, and retirement communities— before settling on a prison population as “the best setting to conduct the trial.” The group acknowledged the need to address important ethical issues, but pointed out that “this approach included potential to control a large portion of dietary intake, a large population with multiple locations, possibility for use of a randomized cluster design, diversity of age and ethnicity, an existing research infrastructure, including an Institutional Review Board, and the existence of a large literature on the ethics of research in prisoners and the likelihood of benefitting future prisoners by demonstrating the level of dietary sodium that optimizes their health outcomes.”

Rob Califf

While the salt experts may have strong differences of opinions, said the former FDA commissioner Rob Califf, “I believe there is a common view that a definitive clinical trial is needed so that public policy can be based on the highest level of evidence. Whether the prison population is the right population is entirely dependent on the acceptability of the trial to the participants, who will be included in considerations of the protocol, both for feasibility and acceptability.  If lower salt in the diet is really better there is much value in proving it beyond a doubt and it would benefit society as well as future prison populations.”

Salim Yusuf

Yusuf also pointed out that the fact that a trial may only be feasible in a controlled environment like a prison is itself evidence that a low sodium guideline is unrealistic.”The fact that this expert group of highly regarded and knowledgeable individuals, in all earnestness proposed a trial in prisoners simply indicates how farcical and ridiculous the proposed targets for salt by certain organizations are! Perhaps this proposal will make people see the dystopian nature of these recommendations.  Even if the trial achieves such low sodium intakes as some guidelines propose and shows benefit (which I seriously doubt), will we expand our prison system so that all of the US can lower their salt and eat a regimented diet?. There may be alternative designs in other populations, but they are not easily identifiable. This expert group has done us a service by getting us to recognize that a large trial is needed but if we are to test the current goals for sodium reduction, it will be very hard to do so.”

Yusuf concluded: “Public health recommendations should not only be evidence based but also feasible — in the case of the extreme sodium reductions, neither appears to have been met ”

Related reading:

• International Experts Call Salt Guidelines Far Too Restrictive
• Salt, Science, And The American Heart Association’s Double Standard
• An Expert’s Perspective: Why Salt Is Not Like Tobacco And Why Guidelines Are Tricky
• Top Cardiologist Blasts Nutrition Guidelines
• The American Heart Association’s Strong Stance Against Science
• Why Guidelines Are Bad For Science
• Recipe For Disaster: The New US Dietary Guidelines
• Why Guidelines Should Be Waged Like War