Generalizable results?
More than 90% of the participants in the Nurses’ Health Study were White, not Hispanic. Can the results be extrapolated to other populations? “The answer: The study needs to be repeated in other populations,” said Dr. Chavarro, “and that’s going to take time. But even without that information, I think we can use this study to inform other populations, regardless of ethnicity.”
Dr. Sotos-Prieto admitted that this hypothesis has not yet been tested in the Spanish population, but she is the author of a similar study that followed nearly 12,000 Spanish adults for a decade using the same PDI. In this study, every 10-point increase in PDI was associated with a 14% lower risk of mortality from any cause (hazard ratio, 0.86) and a 37% lower risk of death from cardiovascular disease (HR, 0.63). She also believes that the recommendations derived from the study could be generalized to other populations “as long as each country’s culture is taken into account, to see how it can be culturally adapted. If it’s a population that consumes a lot of refined cereals, for example, make small changes to whole grains.”
Weighing the evidence
The study has strengths and limitations, owing to its methodology, and Dr. Chavarro himself recognizes that “in terms of hypertensive disorders of pregnancy specifically, this won’t be the last word.” But there is a pressing need to find answers.
The American College of Obstetricians and Gynecologists and the World Health Organization encourage women to follow healthy diets before and during pregnancy. But they provide little guidance on what constitutes a healthy diet when it comes to minimizing the risks of adverse pregnancy outcomes. “They are quite ambiguous and vague,” said Dr. Chavarro.
These new findings suggest that plant-based diets may be one such strategy, particularly because some evidence was found that these diets may be beneficial for women older than 35 years, who are considered a high-risk group.
“There are certainly many ways to eat healthily, but if we think about these pregnancy complications that can have serious consequences for the mother and the fetus, we might consider this as a healthy diet option,” Dr. Chavarro noted.
But is the evidence robust enough to recommend that patients make changes? “Ideally, there will be more studies,” stated Dr. Chavarro. “There are two ways to understand the problem. One is not making recommendations until you have three controlled clinical trials, which, even with the willingness and funding to do so, will take 15-20 years. But if we have to provide the best available information to those who need it today, I think these are solid results for guiding behavior.
“It’s always better if we can make decisions based on solid, incontrovertible information. But it’s not always available, and you must learn to live in both worlds and make decisions with uncertainties,” he concluded.
Dr. Sotos-Prieto and Dr. Chavarro have disclosed no relevant financial relationships.
This article was translated from the Medscape Spanish Edition. A version of this article first appeared on Medscape.com.