Researchers tracking maternal diet during pregnancy found no clear statistical link between consuming ultra-processed foods or red meat and the likelihood of developing postpartum depression, according to a study published in Scientific Reports and covered by News-Medical.
The prospective cohort study investigated whether eating habits during the third trimester influence mental health outcomes after childbirth among a group of women in Iran.
Postpartum depression remains a prevalent form of major depressive disorder affecting reproductive-aged females. Its development stems from a complex interplay of genetic, biological, environmental, and psychosocial factors. Previous epidemiological research produced mixed findings regarding how red meat and ultra-processed foods impact depression pathways in the general population, leaving specific evidence on postpartum vulnerability limited. Postpartum depression has been linked to sub-optimal child growth trajectories.
Investigators enrolled pregnant women in Iran between October 2022 and May 2023 using convenience sampling methods. Eligible participants were at least 18 years old and in their third trimester of pregnancy carrying a singleton fetus. Individuals diagnosed with cancer, hepatitis, autoimmune disorders, psychiatric illnesses, chronic liver disease, severe infections, or abnormal daily caloric intake were excluded from the cohort.
Researchers administered a food frequency questionnaire during the third trimester to evaluate overall dietary intake throughout pregnancy. Daily intake levels of red meat—including beef, lamb, and organ meats—and ultra-processed foods, classified using the NOVA system, were calculated from reported portion sizes and consumption frequencies. Participants were subsequently categorized into tertiles based on their consumption levels of these food groups.
Evaluations for depressive symptoms took place during weeks four to six postpartum using the Edinburgh Postnatal Depression Scale. Investigators established a score of 13 or higher to indicate probable postpartum depression rather than a formal clinical diagnosis.
Baseline demographic data, pre-pregnancy body mass index, and physical activity levels assessed via the Pregnancy Physical Activity Questionnaire were factored into the analysis alongside postpartum infant feeding patterns and neonatal hospitalizations. In addition, height was measured, and pre-pregnancy weight was obtained from records or self-report to calculate body mass index, while a separate postpartum questionnaire recorded birth outcomes, infant sex, and neonatal illness.
The final analysis included 264 participants out of 310 initially enrolled individuals, yielding a mean participant age of 30.7 years. Among this group, 52 women met the threshold for probable postpartum depression. Logistic regression models adjusted for total energy intake, maternal age, education, socioeconomic status, and gestational diabetes—along with pre-pregnancy body mass index and n-3 fatty acid intake—revealed no significant associations between ultra-processed food or red meat intake and probable postpartum depression.
Several methodological limitations restricted the study’s conclusions, including reliance on a food frequency questionnaire that may introduce recall inaccuracies. Additional constraints involved the lack of repeated dietary assessments during earlier trimesters, reliance on a screening questionnaire rather than a clinical diagnosis, and the modest sample size. Larger prospective cohort studies are required to clarify these relationships and determine whether maternal nutrition meaningfully alters postpartum mental health susceptibility.