Does the Mediterranean diet meet nutritional requirements during pregnancy?

In a recent article in Frontiers in public health In the journal, researchers evaluated whether adopting a healthy diet, such as the Mediterranean diet (MedDiet), during pregnancy can meet the unique macro- and micronutrient requirements of pregnancy.

Stady: Diet quality and nutrient density in pregnant women according to adherence to the Mediterranean diet. Photo credit: Antonina Vlasova/Shutterstock.com

background

The diet is usually not enough to meet the nutritional needs of pregnancy, which in turn impairs the growth of the fetus and the health of the mother.

Studies have described that up to 30% of pregnant females are deficient in micronutrients, such as folic acid and vitamins A, B6, C, D, and E. Dietary patterns during pregnancy. However, the modifiable factor may have lasting health consequences for the newborn.

Guidelines for nutritional supplementation during pregnancy vary widely across different geographic regions.

For example, in Spain, they only recommend folic acid and iodine supplementation during pregnancy and mainly rely on adherence to the MedDiet to meet requirements for most other micronutrients.

The MedDiet includes fruits, vegetables, whole grains, legumes, seeds, and nuts in large amounts, and fish, seafood, eggs, and fermented dairy products, such as yogurt, in moderate amounts. Extra virgin olive oil (EVOO) is used as the main source of fat in sauces and cooking.

In the Improving Mothers for Better Prenatal Care trial, the BarCeloNa Program (IMPACT BCN), a MedDiet-based nutritional intervention, showed a 26% reduction in the prevalence of perinatal complications.

Assaf Ballout and others. Showed that adherence to the MedDiet reduces the risk of gestational diabetes, preterm labor, and urinary tract infections.

Several recent studies have described the health benefits of MedDiet for the mother and fetus. However, studies have not explored the extent to which pregnant women in Mediterranean regions benefit from local foods.

About the study

In the current study, researchers conducted a cross-sectional study between February 2017 and August 2021 in Barcelona, ​​Spain, to assess whether higher MedDiet adherence met the micronutrient requirements of pregnant females.

The study group consisted of 1356 pregnant females aged 18 years and in their second trimester (19-23 weeks). They were fluent in Spanish and carried a single, viable, non-deformed fetus, as assessed by ultrasound examination.

At enrollment, the dietitian classified all study participants into three groups based on a 17-item MedDiet adherence score, where scores <6, 6–11, and ≥12 points indicated low, medium, and high adherence to the MedDiet.

The trained personnel also assessed the participants’ cardiac and metabolic health parameters upon enrollment, including body weight, height, waist circumference, body mass index (BMI), and blood pressure (BP).

The researchers also collected the mothers’ sociodemographic data, age, race, etc., and clinical data, for example, levels of physical activity, at enrolment.

Furthermore, the team inquired about each participant’s usual and frequent consumption of the foods included in a Food Frequency Questionnaire (FFQ). They calculated energy and nutrient intake, that is, total dietary fiber, vitamins and minerals, using food intake data derived from the FFQ.

They included participants with energy intakes within predetermined limits ranging from less than 500 calories per day to >3,500 calories per day.

They compared the dietary intake of magnesium, iron, calcium, zinc, sodium, phosphorous, potassium and vitamins B1, B9, B12, A, C, D and E with pregnancy requirements according to the Dietary Reference Intakes (DRIs) in Europe and the United States. American DRI for pregnant women and the Spanish population in general, where higher intake levels than the DRI indicate a lower likelihood of inadequate intake of micro and macronutrients.

Finally, the team used multivariate linear regression models to assess differences in dietary intake below the DRIs between study groups while controlling for confounding factors.

results

The final study sample was 1356 pregnant women, and MedDiet adherence scores, FFQ scores, and total energy intake data were available.

In the group with lower MedDiet adherence scores, maternal age was lower, the number of Latina pregnant women was higher, and there were more smokers; In addition, these women had a higher waist circumference at enrollment and a higher weight and body mass index throughout their pregnancy.

Conversely, in the group with high MedDiet adherence scores, there were more white females, and women had higher education. They consumed more protein, fat, and fiber and fewer carbohydrates.

Among the low- and high-adherence groups, vitamin A and B12 intake was similar, but vitamins B1, B9, C, D, and E varied.

Thus, among participants whose macro- and micronutrient intakes were less than 2/3 of the recommended dietary intakes, the authors observed inadequate intakes of vitamin D, B9, iron, and calcium in 82.3%, 12.3%, 52.6%, and 13 % of the participants, respectively.

Similarly, the authors profiled these two groups with regard to fatty acid intake and noted significant differences in all FA components.

Participants with a higher MedDiet adherence had enough EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), which are essential for the development of the fetus, especially the brain and eyes.

Most notably, the EVOO in MedDiet supplements mono- and polyunsaturated fatty acids (MUFAs and PUFAs) such as oleic, alpha-linolenic and linoleic acids.

conclusions

According to the authors, this is the first study to directly assess whether adherence to a healthy MedDiet is associated with adequate intake of micronutrients (and macronutrients) per dose recommended for pregnancy.

They indicated a direct relationship between nutritional status and adherence to the pregnancy-adapted MedDiet diet.

Although it is an easy-to-follow diet, some nutritional requirements are difficult to meet only with the MedDiet Diet, including in high-income countries. Thus, many of the pregnant females in the study group were deficient in multiple micronutrients, particularly vitamin D and B9, iron and calcium.

However, higher adherence to the MedDiet regimen decreased the proportion of participants who had lower micronutrient intakes (without supplementation) for iron, calcium, folic acid, magnesium, and vitamin C.

These associations remained significant even after adjusting for potential confounding factors, such as age, educational level, and pre-pregnancy BMI, to name a few.

In conclusion, the pregnancy-adapted MedDiet should be promoted as a cost-effective public health strategy in individualized nutritional counseling of pregnant women.

And with little or no financial cost, it can help avoid multiple challenges associated with pregnancy, such as maternal weight gain, nutrient deficiencies, and other complications.