Could tea during pregnancy give your baby a brain boost? Research says yes

Could your daily cup of tea during pregnancy give your child a cognitive advantage? New research uncovers surprising findings on how tea—and not coffee—may influence early brain development.

Study: Impact of tea and coffee consumption during pregnancy on children’s cognitive development. Image Credit: UladzimirZuyeu / Shutterstock

A study conducted by researchers at the Anhui Medical University, China, finds that children of mothers who regularly drink tea throughout pregnancy exhibit higher cognition and fine and gross motor skills.

The study findings are published in the journal Scientific Reports.

Background

Tea and coffee are the most popular beverages worldwide. Several studies have highlighted both positive and negative health effects associated with tea or coffee consumption, which can be attributed to the wide variety of compounds present in these beverages. Caffeine is one of the main compounds in both tea and coffee.

On average, tea contains less caffeine than coffee. Among various types of tea, black tea contains more caffeine than green tea. However, the specific amount varies depending on the tea brand, brewing time, and water temperature. The study also notes that there is no consistent trend in caffeine levels across tea types. Additionally, tea contains other bioactive compounds, such as polyphenols and catechins, which may play a role in cognitive benefits.

Maternal caffeine consumption has recently been linked to adverse pregnancy outcomes, including miscarriage, fetal growth restriction, low birth weight, and preterm birth. Rapid and easy transfer of caffeine to amniotic fluid and breast milk through the placental barrier might be responsible for these outcomes.

Studies on child neurodevelopment have produced mixed results. While some have identified associations between maternal caffeine consumption and cognitive decline, others have reported no significant impact on child neurodevelopment.

Given the observational nature of the study, researchers at the Anhui Medical University designed this research to explore correlations rather than establish causation between maternal tea or coffee consumption during pregnancy and cognitive development in children.

Study Design

The study was conducted on 1,423 mother-child pairs from the Chinese National Birth Cohort (CNBC). The mothers were asked to provide information on their tea and coffee consumption status during pregnancy’s first, second, and third trimesters.

A widely used cognition assessment scale was used to determine cognitive functions in infants aged 0 to 42 months.

Appropriate statistical analysis was carried out to explore the impact of maternal tea and coffee consumption during pregnancy on children’s cognitive development. Importantly, the study also analyzed the patterns of tea and coffee consumption throughout pregnancy rather than only examining individual trimesters.

Potential confounders that were adjusted in the analysis included maternal age, pre-pregnancy body mass index, maternal occupation, family income, education level, maternal smoking, passive smoking, alcohol consumption, maternal psychological status, and pregnancy vomiting. Additionally, sensitivity analyses accounted for pregnancy complications, birth weight, breastfeeding, and folic acid intake, which could influence cognitive development.

Study Findings

About 36%, 6%, and 4% of enrolled mothers reported consuming tea in the first, second, and third trimesters of pregnancy, respectively. Similarly, 30%, 1.5%, and 0.9% of mothers reported coffee intake in the first, second, and third trimesters, respectively. The study did not find significant differences in outcomes between green and black tea consumers.

Impact of Maternal Tea Consumption on Cognitive Development in Infants

The statistical analysis controlling for potential confounders revealed that maternal tea consumption in the second trimester is associated with significantly higher cognitive functions and fine motor skills in infants aged 36 months. On the other hand, maternal tea consumption in the third trimester exhibited a significant association with higher cognitive functions and gross motor skills in infants.

However, the study also found that children born to mothers who consumed tea throughout pregnancy had the highest cognitive, fine motor, and gross motor scores compared to those whose mothers only consumed tea in one trimester.

Impact of Maternal Coffee Consumption on Cognitive Development in Infants

Unlike the strong impact of maternal tea consumption, the study did not find any significant association between maternal coffee consumption during pregnancy and an infant’s cognitive development. This lack of correlation was observed despite coffee typically containing more caffeine than tea, suggesting that other factors beyond caffeine content may influence neurodevelopment.

Study Significance

The study finds that maternal tea consumption during pregnancy is associated with improved cognitive development in infants. However, no such benefits have been observed for maternal coffee consumption during pregnancy.

Specifically, the highest cognitive benefit has been observed in infants whose mothers consumed tea during the second and third trimesters of pregnancy. The study also suggests that maintaining a consistent tea-drinking habit throughout pregnancy, rather than consuming tea only in one trimester, may provide the greatest benefit. This observation indicates that the late gestational period is likely the key period for the effect of maternal tea consumption during pregnancy on infant neurodevelopment.

Existing evidence on neurodevelopmental effects of intrauterine caffeine exposure has highlighted several adverse outcomes, including cognitive decline, behavioral abnormalities, lack of attention, hyperactivity, and daydreaming in children aged 9 to 10 years.

In contrast, some studies have reported that low-to-moderate caffeine intake during pregnancy is not associated with cognitive or behavioral impairments in children. Collectively, these observations indicate that caffeine’s neurodevelopmental effects may be dose-dependent, with excessive intake posing potential risks.

The most recent evidence suggests that pregnant women should limit coffee consumption to ensure that daily caffeine intake does not exceed 200 mg/day, which aligns with recommendations from the European Food Safety Authority (EFSA) and other regulatory bodies.

Study Limitations

The study has several limitations:

• The exact amount of tea and coffee consumed was not measured; only the frequency of intake was recorded.
• Different types of tea (e.g., green vs. black) were not separately analyzed in later trimesters despite their differences in caffeine and polyphenol content.
• The study is observational, meaning that while associations were found, causation cannot be confirmed. Other factors such as maternal diet, socioeconomic status, and lifestyle may also influence cognitive development.
• The research was conducted in China, which may limit generalizability to other populations with different dietary and cultural habits.

Future research with larger sample sizes and controlled trials is needed to confirm these findings and explore the biological mechanisms underlying the observed associations.