An article recently published online in the journal Hypertension proposes a research study to help resolve the ongoing debate over the long-term benefits of a low-salt diet. The authors contend that this study would have to take place in a controlled environment, and conclude that the best prospect would be to conduct a randomized controlled trial (RCT) in prisons.
Research involving incarcerated persons is ethically controversial. One report referred to the prison setting as “an inherently coercive environment.” Could informed consent in such a setting ever really be voluntary? Federal regulations address such issues, stating: “Inasmuch as prisoners may be under constraints because of their incarceration which could affect their ability to make a truly voluntary and uncoerced decision whether or not to participate as subjects in research, it is the purpose of this subpart to provide additional safeguards for the protection of prisoners involved in activities to which this subpart is applicable.”
Clearly, many variables must be addressed when determining whether such research is ethically sound.
Note: I also recently spoke with reporter Gina Kolata of the New York Times about this subject for her article “The Ideal Subjects for a Salt Study? Maybe Prisoners.”
Benefits of Consent
The article’s authors claim that their proposed study has the potential to benefit future prisoners. But federal regulations require that there be potential benefits to the health or well-being of those presently enrolled in a study. Prisoners enrolled in the proposed study could benefit, but only if the sodium restriction turns out to be justified. If not, there is no benefit to either group in this RCT. However, if the sodium-restriction hypothesis is justified, the intervention group would likely benefit in the long term. To the extent that it would be problematic or too costly to implement the sodium-restricted diet in all U.S. prisons, it remains unknown whether future prisoners would benefit.
Challenges and Uncertainty in Prison Research
Let us assume that the regulatory barrier can be appropriately surmounted. The following are other ethical concerns, practical challenges and uncertainties.
Visitors to prisons are typically permitted to bring food to the prisoners, subject to restrictions (for example, no sauces on prepared foods, because a sauce may contain alcohol or controlled substances). Study enrollees would likely be prohibited from receiving food packages of any type from visitors. Though it would deny prisoners a benefit to which they are currently entitled, this would be stipulated in the informed-consent process to which they would have to agree in order to be in the study.
Such restrictions would not prevent prisoners from obtaining food from other prisoners’ visitors, unless all subjects in the experiment were housed in a special unit. Obviously, for ethical reasons, such a unit could not be anything like solitary confinement. That could potentially be costly. (The Hypertension article also refers to other prohibitive costs in such studies.) Were the prisoners to remain in the general population, some severe restrictions would have to be in place to avoid this type of contamination of the study results.
Visitors can also provide prisoners with snacks from vending machines in prison visiting rooms. These are likely the foods highest in salt content. How could these snacks be monitored? Prison guards would have to have the names of all prisoners in the study and then would have to prohibit the visitors from purchasing snacks for those prisoners. That hardly seems feasible—or ethically acceptable. An alternative would be to prohibit visits altogether, another unacceptable ethical restriction. Or a more-restrictive area for prisoners enrolled in the study and their visitors could be provided. That would, once again, penalize prisoners in the study by denying them the usual amenities.
Of course, all these restrictions would be included in the informed-consent documents, so it could be argued that if prisoners accept the restrictive conditions, that would be their choice.
Questions of Compensation
Would prisoners be paid money or other “valuable considerations” (e.g., special benefits not available to the general prison population)? In my view, this would not be an ethical barrier in principle, though other ethicists might consider such ancillary benefits to be an “undue influence” (the language used in the U.S. regulations). One provision states: “Any possible advantages accruing to the prisoner through his or her participation in the research, when compared to the general living conditions, medical care, quality of food, amenities and opportunity for earnings in the prison, [must] not [be] of such a magnitude that his or her ability to weigh the risks of the research against the value of such advantages in the limited choice environment of the prison is impaired.”
Some prisoners have argued that the federal regulations for prison research are too strict. They say they want to “give back to society” as a result of their previous transgressions. That’s the altruistic reason. A different assessment is that prisoners are eager to get into studies conducted in prisons; when such prisoners participate in research, they are carefully monitored, possibly housed in a better environment, possibly given better medical treatment (so other medical factors do not alter the study results) and likely to enjoy better overall treatment. This is especially relevant to the food provided in a study such as this. If the prisoners in the study were to receive regular prison meals, some of them as currently prepared (for the control group) and others with the low-sodium content, this would not be an issue. However, if the food for the low-salt cohort were to be prepared outside the prison, perhaps the food itself would be more nutritious. That alteration could contaminate the results of the study; such food might include more fruits and vegetables and exclude trans fats, and offer other deviations from the typical prison diet.
Assuming that prisoners will not be paid for participation, there is no good reason to prevent them from enrolling in a low-risk study such as this. The risks and benefits are those of everyday life, and there is no “coercive offer” that would constitute a violation of research ethics or U.S. regulations. On the contrary, I believe that any ancillary benefits, such as the relief from boredom afforded by doing something outside the typical prison routine, are acceptable. It seems paternalistic to deny prisoners the opportunity to participate in research that has no greater risks than those encountered in everyday life. I conclude that the type of study proposed in the Hypertension article can be ethically acceptable if the challenges described here can be met.