Fish Consumption Linked To Lower Pregnancy Hypertension Risk
A large Japanese study finds women who eat more fish before and during pregnancy have significantly lower odds of developing hypertensive disorders.
Higher fish consumption before and during pregnancy is linked to a lower risk of hypertensive disorders, a serious complication affecting five to ten percent of pregnancies worldwide. New research suggests this dietary choice, particularly in a first pregnancy, could offer substantial protective benefits.
A prospective study of 86,009 Japanese women found that higher fish intake before pregnancy was associated with 34 percent lower odds of early-onset hypertensive disorders. For first-time mothers, the benefit was even greater, with a 43 percent lower odds of early-onset disorders. The associations were most pronounced among women in their first pregnancy and were not statistically significant among women who had previously given birth.
Higher intake during pregnancy was also beneficial, linked to a 14 percent lower odds of overall hypertensive disorders. In first-time mothers, higher consumption during pregnancy was tied to a 21 percent lower odds of late-onset disorders. The research indicates the connection involves whole fish consumption, not only the intake of n-3 polyunsaturated fatty acids (PUFAs) alone.
Study Design
The Japan Environment and Children's Study (JECS) analyzed data from 86,009 women, dividing them into five groups based on their level of fish consumption. Researchers examined fish intake at two specific time points: the year before conception and during mid-to-late pregnancy. This large-scale, observational study tracked these dietary patterns against the development of hypertensive disorders of pregnancy.
Because the study was observational, with diets not controlled and participants not randomized, it can show a link but cannot prove that eating more fish directly causes the reduced risk. Takuya Inouye, a researcher involved with the study, noted the team's longstanding interest in the topic, stating: "Given the importance of n-3 PUFAs during pregnancy, we have long been interested in how fish consumption may influence maternal and child health."
Key Findings
The analysis revealed clear patterns, with the strongest protective associations appearing for women expecting their first child. The link between fish consumption and reduced risk was stronger in first pregnancies than in subsequent pregnancies. Associations between total n-3 PUFA intake and hypertensive disorders were weaker and less consistent than those for whole fish.
| Time of Intake | Disorder Type | Group Affected | Risk Reduction (Adjusted Odds Ratio) |
|---|---|---|---|
| Before Pregnancy | Early-onset HDP | All Women | 34% lower (0.66) |
| Before Pregnancy | Early-onset HDP | First-time Mothers | 43% lower (0.57) |
| During Pregnancy | Overall HDP | All Women | 14% lower (0.86) |
| During Pregnancy | Late-onset HDP | First-time Mothers | 21% lower (0.79) |
Limitations
The research cannot prove cause and effect because diet was not controlled and participants were not randomized. Notably, the study found no statistically significant association between fish intake and hypertensive disorders among women who had previously given birth. This suggests that the protective mechanism may be most relevant during a first pregnancy.
The study was published in Volume 65 of the European Journal of Nutrition. Further research is needed to confirm whether increasing fish intake can prevent hypertensive disorders in pregnancy.
