In 10 seconds? A new association between Mediterranean Diet and pregnancy outcomes has been evaluated, finding that women who stick to this type of diet during pregnancy have a lower risk of developing preeclampsia and gestational diabetes.

What are preeclampsia and gestational diabetes? Preeclampsia – which is mostly mild - affects the mom’s blood vessels and the baby’s blood supply. The condition usually starts affecting some pregnant women (about 4% in the US) from week 20 of the pregnancy. It is usually accompanied by high blood pressure, potential headaches, and blurred vision and is “cured” by delivering the baby, sometimes early. Gestational diabetes (affecting about 2-10% of women in the US) develops during pregnancy for women who did not have diabetes before and also disappears after giving birth. Once it’s been diagnosed, it is important to keep a healthy diet and to keep active.

What did the researchers discover? You have to know that diet quality among US women is very poor, and these nutritional habits don´t change by the time of conception or during pregnancy. The most important point is that this work added to the body of evidence that modifications in our lifestyles improve our health. Regarding the numbers, the study found that a greater commitment to the MedDiet lowers the risk of any adverse pregnancy outcome (APO) by 21%, with preeclampsia risk down by 28% and gestational diabetes odds down by 37%. And finally, this association is stronger among women with advanced maternal age.

So, how did they do this study? It was not easy! Researchers evaluated a large group (more than 7,000 pregnant women) and scored them according to their adherence (i.e. how much they stick) to the MedDiet. Through a "Food Frequency Questionnaire" during the gestational time, they classified women as low, moderate, and high. And then, they associated the score with any adverse pregnancy outcome. Finally, they searched for other associations, like age, ethnicity, and smoking, among others.

A questionnaire... that does not lead to robust results, right? Indeed, this is the weak spot of the study: much of the data was self-reported, and the participants had access to a leading medical center – which, the authors admit – could lead to an underestimation of the associations. And, being an observational study, the researchers could not establish causation i.e. “if I eat a MedDiet my risk will definitely go down by X%”. Still, as I mentioned, the importance of the study is that it strengthens the argument that lifestyle changes can lead to better pregnancy outcomes.

The Mediterranean Diet Pyramid - what to eat and how often? Source: North Carolina Cooperative Extension
The Mediterranean Diet Pyramid - what to eat and how often? Source: North Carolina Cooperative Extension

And how does changing the diet improve pregnancy outcomes? Well... in this case, the MedDiet has been linked to health and longevity, as well as associated with a lower risk for multiple chronic diseases and mortality. So, women who change their diet to the MedDiet have a lower risk of suffering any adverse pregnancy outcome, due to the fact the lower fat intake in the MedDiet has been linked to decreased adiposity, improved glycemic profiles, blood pressure, inflammation, and insulin resistance.

So – just to make sure – the MedDiet is good for pregnancy? Yes! And the most important is that women of all races and ethnicities benefited equally. For example, in Spain, most pregnant women do not meet nutritional recommendations, while it has been shown that in pregnant women who stick to a MedDiet, the risk of gestational diabetes is low. The same results were observed in the UK, where pregnant women who stick to MedDiet have a 35% less chance to develop gestational diabetes.

And what about fertility? As we talked about before, the MedDiet is a low-fat (and sodium) intake diet, and this improves the ‘inflammatory profile’. These nutritional characteristics improve fertility parameters both in men and women. The anti-inflammatory dietary pattern of the MedDiet contributes to regular menstrual cycling and better sperm quality (improving motility), as well as reduces implantation failure.

The MedDiet at a glance

That is true! Not only for you but for your offspring!

As the name suggests, a Mediterranean diet is based on the traditional cuisine of the countries around the Mediterranean Sea, such as Greece and Italy.

Since it was noted that the population in that part of the world has a lower risk of heart disease, this diet is one of the most studied with more than 5,000 reports in the last 5 years.

Commonly, the MedDiet (as is known in the scientific field) is based on fruits, vegetables, legumes, and grains, and olive oil is the source of added fat, while fish, seafood, dairy, poultry, and red meat are eaten occasionally.

And here is one extra benefit: It is well documented that diet interventions, such as MedDiet, influence the offspring's body size.

Monica has distilled 13 research papers, saving you 45.5 hours of reading time.

The Science Integrity Check of this 3-min Science Digest was performed by Dr. Ralph Papas.