Researchers tested whether natural compounds found in certain foods (called salicylates) could help prevent preeclampsia, a serious pregnancy condition where blood pressure gets dangerously high. Using pregnant rats, they compared dietary salicylates to aspirin to see if either could protect against this condition. While the compounds showed some promise in reducing certain markers of the disease and protecting the placenta, they didn’t prevent the main problem of high blood pressure. The findings suggest that while these compounds have some benefits, they may not be a complete solution for preventing preeclampsia on their own.

The Quick Take

  • What they studied: Whether eating foods containing salicylates (natural compounds similar to aspirin) could prevent or reduce preeclampsia, a dangerous pregnancy condition involving high blood pressure and protein in urine.
  • Who participated: Pregnant laboratory rats divided into six groups. Some received dietary salicylates at different amounts, some received aspirin, and some received no treatment. All groups were exposed to a chemical that triggers preeclampsia-like symptoms.
  • Key finding: Dietary salicylates and aspirin did not prevent high blood pressure in the rats with preeclampsia. However, the lower dose of salicylates reduced protein leaking into urine, and both treatments helped prevent harmful changes to the placenta and improved certain blood markers related to the disease.
  • What it means for you: This research suggests that while salicylates and aspirin may help with some aspects of preeclampsia, they don’t address the main problem of high blood pressure. Pregnant women at risk for preeclampsia should continue following their doctor’s recommendations rather than relying on dietary salicylates alone. More research in humans is needed before any dietary recommendations can be made.

The Research Details

This was an animal study using pregnant rats to test whether dietary salicylates could prevent preeclampsia. The researchers created preeclampsia-like symptoms in the rats by giving them a chemical called L-NAME in their drinking water during pregnancy. They then divided the rats into different groups: some received low doses of salicylates in their food, some received high doses, some received aspirin (adjusted to match the salicylate amounts), and some received no treatment. The researchers measured blood pressure, urine protein levels, placental health, and various blood markers to see if the treatments helped.

The study design allowed researchers to carefully control all variables and directly observe how salicylates and aspirin affected the development of preeclampsia. By using rats, scientists could study the disease in a controlled way that wouldn’t be possible or ethical in pregnant women. The researchers measured multiple outcomes to get a complete picture of how these compounds affected different aspects of the disease.

This research approach is important because preeclampsia is a serious condition that affects real pregnant women, but studying it directly in humans is difficult and risky. Animal studies allow scientists to test potential treatments safely and understand how they work in the body. The findings help researchers decide whether a treatment is worth studying further in human trials. Since aspirin is already used to help prevent preeclampsia in high-risk women, testing whether natural food compounds have similar effects could lead to new prevention strategies.

This study was published in PLoS ONE, a peer-reviewed scientific journal, which means other experts reviewed the research before publication. The study used a randomized design where rats were randomly assigned to different groups, which helps reduce bias. The researchers measured multiple outcomes and used proper statistical methods. However, this is an animal study, so results may not directly apply to humans. The study was relatively small in scope, and the researchers did not specify the exact number of rats used in each group. Animal studies are valuable for understanding disease mechanisms but need to be followed by human studies to confirm findings.

What the Results Show

The main finding was that neither dietary salicylates nor aspirin prevented high blood pressure in rats with preeclampsia-like symptoms. This was disappointing because high blood pressure is the defining feature of preeclampsia in pregnant women. The researchers had hoped these compounds would lower blood pressure, but they did not.

However, the treatments did show benefits in other areas. The lower dose of dietary salicylates significantly reduced the amount of protein leaking into the urine, which is another sign of preeclampsia. Both the salicylates and aspirin prevented harmful changes to the placenta (the organ that nourishes the baby during pregnancy) that normally occur with preeclampsia.

Both treatments also improved an important blood marker called the sFlt/PLGF ratio. This ratio becomes abnormal in preeclampsia and is associated with poor outcomes for both mother and baby. By preventing this ratio from becoming abnormal, the treatments may have helped protect against some of the harmful effects of preeclampsia, even though they didn’t prevent high blood pressure.

The higher dose of aspirin reduced levels of a protein called VEGFR2 in the placenta. This protein is involved in blood vessel formation, and abnormal levels are associated with preeclampsia. The fact that aspirin affected this protein suggests it may work through specific biological pathways to influence the disease. The lower dose of salicylates appeared to be more effective than the higher dose in some measures, suggesting that more isn’t always better with these compounds.

Previous research has shown that low-dose aspirin can reduce the risk of preeclampsia in high-risk pregnant women by about 15-20%. This study tested whether dietary salicylates (natural compounds with similar properties to aspirin) could provide similar benefits. The findings suggest that while salicylates have some of the same effects as aspirin on placental health and certain blood markers, they may not be as effective at preventing the disease overall. The results align with the idea that preventing preeclampsia requires addressing multiple biological pathways, and no single compound may be sufficient on its own.

This study has several important limitations. First, it was conducted in rats, not humans, so the results may not directly apply to pregnant women. Rats develop preeclampsia differently than humans, and what works in rats doesn’t always work in people. Second, the study didn’t specify exactly how many rats were used, making it difficult to assess the statistical power of the findings. Third, the study only looked at short-term effects during pregnancy in rats; it didn’t examine long-term effects or outcomes for the babies. Finally, the study used a chemical to artificially create preeclampsia-like symptoms rather than studying naturally occurring preeclampsia, which may not perfectly mimic the human disease.

The Bottom Line

Based on this research, dietary salicylates should not be considered a proven treatment or prevention for preeclampsia. Pregnant women at high risk for preeclampsia should continue following their doctor’s recommendations, which may include low-dose aspirin if appropriate. While this study suggests salicylates have some beneficial effects on placental health and certain blood markers, the failure to prevent high blood pressure—the main feature of preeclampsia—limits their potential usefulness. More research in humans is needed before any dietary recommendations can be made with confidence.

This research is most relevant to pregnant women at high risk for preeclampsia and their healthcare providers. Women with risk factors such as high blood pressure, diabetes, kidney disease, or a previous history of preeclampsia should be aware of this research but should not change their treatment plans based on it alone. The general public should understand that while natural compounds may have health benefits, they are not automatically safer or more effective than medications that have been thoroughly tested in humans. This research is also important for scientists studying preeclampsia who are looking for new prevention strategies.

If dietary salicylates were to be used as a preventive treatment (which is not currently recommended based on this research), any benefits would likely need to be present throughout pregnancy, as preeclampsia can develop at any point. In this rat study, treatments were given during the period when preeclampsia-like symptoms developed. In humans, prevention strategies are typically started early in pregnancy for high-risk women. However, since this research did not show clear preventive effects, realistic expectations should be low until human studies are conducted.

Want to Apply This Research?

  • Users at risk for preeclampsia could track blood pressure readings daily (if they have a home monitor) and note any symptoms like headaches, vision changes, or swelling. They could also log their aspirin use if prescribed by their doctor, along with any dietary sources of salicylates, to help their healthcare provider monitor their condition.
  • Rather than trying to increase salicylate intake based on this research, users should focus on following their doctor’s prescribed treatment plan. If prescribed low-dose aspirin, they should set daily reminders to take it consistently. Users could also track foods high in salicylates (like berries, tomatoes, and leafy greens) as part of a healthy pregnancy diet, but should not view this as a replacement for medical treatment.
  • For long-term tracking, users should maintain a record of blood pressure readings, weight gain, and any symptoms of preeclampsia (headaches, vision problems, upper abdominal pain, swelling). They should share this information with their healthcare provider at each prenatal visit. The app could send reminders for regular prenatal appointments and prompt users to report any concerning symptoms immediately to their doctor.

This research was conducted in laboratory rats and has not been tested in pregnant women. The findings do not support using dietary salicylates as a treatment or prevention for preeclampsia. Pregnant women, especially those at high risk for preeclampsia, should not change their medical treatment based on this research. All decisions about pregnancy care, including whether to take aspirin or make dietary changes, should be made in consultation with a qualified healthcare provider. If you are pregnant or planning to become pregnant and have risk factors for preeclampsia, discuss appropriate prevention strategies with your doctor. If you experience symptoms of preeclampsia such as severe headaches, vision changes, upper abdominal pain, or sudden swelling, seek immediate medical attention.