Pre-eclampsia (PE), as well as gestational diabetes mellitus (GDM), may increase the risk of maternal and fetal adverse effects, but researchers suggest that polyphenol intake during pregnancy may protect against progression of the disease. disease through antioxidant activity.
Polyphenols found in chocolate, tea, fruits, berries, and other food products are natural compounds with proven health benefits, such as improving glucose tolerance and redox status, and reduction of chronic low-grade inflammation and hepatic steatosis, which inhibit disease pathogenesis.
“At the molecular level, GDM and PE conditions share an imbalance in prooxidant/antioxidant mechanisms. Many studies have suggested that ingesting polyphenol-enriched extracts or polyphenol-rich foods can have positive effects on maternal and fetal health during pregnancy,” write the authors of the recent meta-analysis.
GDM and PE are common in pregnancy and associated with an increased risk of hypertension and gestational PE. Meanwhile, GDM affects 6-25% of pregnant women, the researchers explain.
“Hyperglycemia during pregnancy is associated with an increased risk of suffering pregnancy complications, but also impacts the development of offspring.”
Additionally, women with DG often have lower levels of circulating antioxidants, such as selenium, zinc, vitamin E, and total antioxidant capacity, than women with normal pregnancies.
In the case of PE, “the pathological alterations are associated with the production of oxidative and nitrosative free radicals by the placenta, considered to be one of the main molecular determinants of disease during pregnancy”, they say.
Treatment of GDM is fundamental to prevent pregnancy complications and infant death, as well as to protect mother and child from long-term consequences. Additionally, there is no cure for PE, other than childbirth, so management is key to reducing the severity of the condition.
The researchers conducted a systematic review and meta-analysis of 12 studies on polyphenol consumption and pregnancy complications, eight of which focused on the risks of DG and four on PE. Subjects were recruited from hospitals, medical practices or a national cohort.
Two GDM studies focused on the effects of polyphenol intake from food sources of coffee, chocolate, and soy isoflavones on a total cohort of 162,443 people. The results of the eight GDM studies were based on questionnaires or on face-to-face or telephone interviews.
Other polyphenol-rich foods covered by the study data included tea, fruits and berries. Total polyphenols, soy isoflavones, total flavonoids and total anthocyanin intake were assessed.
Studies that quantified total intake of polyphenols or their subclasses and those that assessed the association between polyphenol intake and PE without gestational hypertension were analyzed separately.
Of the four studies that assessed the relationship between consumption of polyphenol-rich foods during pregnancy and the risk of PE, one compared low consumption to high consumption and three compared no consumption to high consumption. high.
No association was found between overall polyphenol intake and risk of GDM or PE in this meta-analysis. However, in subtype analyses, a protective effect (RR = 0.78) was noted against DG.
Paradoxically, subtype analyzes of 88,073 women in two studies found that drinking coffee or chocolate helped reduce the risk of PE.
“This could imply a possible protective effect of these nutrients that deserves further study,”indicates the report.
Despite strong evidence on the blood pressure benefits of polyphenols that induce vasodilation (like resveratrol), their role in preventing pre-eclampsia is unknown, the authors comment.
Recent studies also demonstrate the positive effects of fruit and vegetable polyphenols on glucose homeostasis through broad mechanistic activity (inhibition of digestive enzymes, reduction of glucose transporter activation in epithelial cells of the small intestine , for example) that improves glucose tolerance.
The lack of positive effects in the meta-analysis may be related to the limited number of studies and the “heterogenicity of interim studies“say the authors. Polyphenol intake before pregnancy was another unknown variable that may have impacted the results.
Nevertheless, they emphasize the need to improve prevention strategies through dietary changes and increased physical activity, but add “Whether polyphenols in particular have more benefits associated with lower risk is unknown/uncertain.”
“Even though the clinical effects of polyphenols might be short-term, the benefits are expected to occur with chronic consumption,” they add.
Published online November 19, 2022: http://doi.org/10.3390/antixo11112294
“Association of polyphenol consumption with the risk of gestational diabetes mellitus and preeclampsia: a systematic review and meta-analysis”
Authors: Jorquera, G., Fornes, R., Cruz, G. and Thomas-Valdés, S.