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.”

McCarron described the process that led to the publication of a paper written by scientists who previously have been completely unable to find common ground. ”Our commentary grew out of the possibility that the intransigent position for or against population-wide salt restriction could only be addressed if a balance of perspectives from experts in the field could be assembled and a civil discussion ensue. Civil was the critical word as the dialogue around sodium and health had become so contentious that little chance existed the science would move forward in a constructive manner. To start with Dr. Jones and I had to develop amongst ourselves a confidence that well intentioned professionals could significantly disagree as to the interpretation of the most recent research that challenged the current paradigm of lower sodium lowers blood pressure and by extrapolation improves ones health and life expectancy, but still seek a way forward. The original group, that I have termed the ‘Jackson 6’, met the diversity of views and experience Dr.Jones and I sought. Respect among all of those diverse views allowed us to reach a unanimous agreement on the need for a RCT and a commitment to communicate that agreement and an approach to address it.”
Jones acknowledged that “trials in a prison population are controversial and difficult. There are 2 key issues here.  The study will benefit prisoners.  Prisoners are not free to select their own nutrition choices.  Therefore, understanding the dietary sodium issue clearly will benefit prisoners who depend on prison leaders for nutrition choices.  Also, as recommended by the Institute of Medicine (now National Academy of Medicine), this kind of study is only feasible in a controlled population.”

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 was not an author of the paper but supports the concept of a large clinical trial, though he has been one of the leading critics of low sodium guidelines for the general population. “Some guidelines recommend that reducing salt intake to very low levels (below 2.3 g of sodium intake per day, or even  below 1.8 g/d) in entire populations is a target we should strive for. The problem is that there is little evidence from long term studies in free living populations that this is feasible (under 5% of the North American population consumes such low levels), safe or will reduce cardiovascular events or death rates. In fact, there are concerns from several observational studies conducted by different investigators from several countries that such low intakes of sodium (which is substantially lower than the average salt intake in the US or Canada) may be associated with higher mortality and higher cardiovascular events. While observational  studies have inherent limitations, given the concern that such low levels of intakes of sodium is associated with poorer outcomes, (and no study suggests  that they improve outcomes), it is premature and perhaps even unsafe to recommend that entire populations reduce their salt intake substantially. Those who advocate such extreme lowering of sodium (or salt) intake should work to develop reliable evidence on safety and benefit for their recommendations. This requires large and long term randomized trials. Until they are completed, it is prudent not to advocate for extreme reduction of salt intakes in the diets of most Western 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 ”

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  1. dearieme says

    People who get their thrills by denying other people their pleasures are now, it is proposed, to be given the power to enforce their will on prisoners.

    Is this a stratagem by the anti-anti-salters designed to show the anti-salters in an unfavourable light?

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