Anxiety and stress disorders are increasingly common in pregnant women and it is estimated that one in five mothers-to-be may suffer from them.
Several studies indicate that the Mediterranean diet, which promotes the intake of plant foods rich in antioxidants, such as fruits, vegetables, extra virgin olive oil and whole grains, is associated with better wellbeing and mental health.
"The IMPACT study, conducted between 2016 and 2022 with the support of Fundació "la Caixa", has already shown that the Mediterranean diet or mindfulness during pregnancy reduces the risk of having a baby with a low birth weight. However, the influence of the Mediterranean diet on women’s stress, anxiety, mental state, quality of life and sleep during pregnancy was not yet known", explains Fàtima Crispi, a researcher at BCNatal and in the IDIBAPS group Fetal and perinatal medicine, both led by Eduard Gratacós.
Together with Francesca Crovetto at Hospital Sant Joan de Déu and Ramon Estruch’s Cardiovascular risk nutrition and aging team at IDIBAPS, Crispi leads a secondary study to the IMPACT study in which 1,221 high-risk pregnant women participated, distributed randomly in three different groups at 19-23 weeks of gestation.
One group followed an intervention to promote the Mediterranean diet through personalised visits with nutritionists. The researchers encouraged the mothers-to-be to increase their intake of whole grains (five servings per day), vegetables and dairy products (three servings per day), fresh fruit (two servings per day), legumes, nuts, fish and white meat (three servings per week), as well as the use of olive oil for cooking and dressing.
Another group received the usual care during pregnancy according to established institutional protocols, but without any special intervention.
According to data published in the journal Nutrients, the intervention based on the Mediterranean diet reduced maternal anxiety and stress by 25% to 28%, while also improving expectant mothers’ wellbeing and sleep quality compared to the subgroup that received no intervention.
The researchers came to this conclusion after analysing the stress questionnaires completed by the participants and measuring levels of stress-related metabolites in urine samples such as cortisol and cortisone. "Some previous studies, like Predimed, had linked the Mediterranean diet to improved wellbeing and lower stress levels, but these were studies of non-pregnant women", Crispi says. "This is the first clinical trial with pregnant women evaluating and demonstrating it". The study also concludes that the beneficial effects appear shortly after the start of the intervention.
"Considering the growing importance of the role of mental health during pregnancy, these results could imply promotion of the Mediterranean diet adapted to pregnant women as a powerful public health strategy", Crovetto says.
However, the authors indicate that the study has some limitations. "Many of the participants were of white ethnicity and of a medium-high socio-economic level", Crovetto says. "Therefore, the finding should not be extrapolated to other populations with different characteristics. We will need to conduct new studies with greater population diversity that also evaluate the mechanisms responsible for the observed effects of the Mediterranean diet".
The project has received funding from Fundació "La Caixa", the Cerebra Foundation for the Brain Injured Child, the Agència de Gestió d'Ajuts Universitaris i de Recerca (AGAUR), Instituto de Salud Carlos III, the University of Barcelona, the Centro de Investigaciones Biomédicas en Red sobre Enfermedades Raras (CIBERER), the Centro de Investigaciones Biomédicas en Red-Fisiopatología de la Obesidad y Nutrición (CIBEROBN) and the Centro de Investigaciones Biomédicas en Red de Salud Mental (CIBERSAM).
Reference article
Casas I, Nakaki A, Pascal R, Castro-Barquero S, Youssef L, Genero M, Benítez L, Larroya M, Boutet ML, Casu G, Gómez-Gómez A, Pozo OJ, Morilla I, Martínez-Àran A, Vieta E, Gómez-Roig MD, Casas R, Estruch R, Gratacos E, Crispi F, Crovetto F. Effects of a Mediterranean Diet Intervention on Maternal Stress, Well-Being, and Sleep Quality throughout Gestation-The IMPACT-BCN Trial. Nutrients. 2023 May 18;15(10):2362. doi: 10.3390/nu15102362.
