Maternal consumption of coffee and tea during pregnancy and risk of childhood brain tumors: results from an Australian case–control study

Maternal smoking, consumption of alcohol, and caffeinated beverages during pregnancy and the risk of childhood brain tumors: a meta-analysis of observational studies

BACKGROUND

We conducted this meta-analysis to investigate the potential association between maternal smoking, alcohol and caffeinated beverages consumption during pregnancy and the risk of childhood brain tumors (CBTs).

METHODS

A thorough search was carried out on PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Internet to identify pertinent articles. Fixed or random effects model was applied to meta-analyze the data.

RESULTS

The results suggested a borderline statistically significant increased risk of CBTs associated with maternal smoking during pregnancy (OR 1.04, 95% CI 0.99-1.09). We found that passive smoking (OR 1.12, 95% CI 1.03-1.20), rather than active smoking (OR 1.00, 95% CI 0.93-1.07), led to an increased risk of CBTs. The results suggested a higher risk in 0-1 year old children (OR 1.21, 95% CI 0.94-1.56), followed by 0-4 years old children (OR 1.12, 95% CI 0.97-1.28) and 5-9 years old children (OR 1.11, 95% CI 0.95-1.29). This meta-analysis found no significant association between maternal alcohol consumption during pregnancy and CBTs risk (OR 1.00, 95% CI 0.80-1.24). An increased risk of CBTs was found to be associated with maternal consumption of caffeinated beverages (OR 1.16, 95% CI 1.07-1.26) during pregnancy, especially coffee (OR 1.18, 95% CI 1.00-1.38).

CONCLUSIONS

Maternal passive smoking, consumption of caffeinated beverages during pregnancy should be considered as risk factors for CBTs, especially glioma. More prospective cohort studies are warranted to provide a higher level of evidence.

Environmental Pollution and Risk of Childhood Cancer: A Scoping Review of Evidence from the Last Decade

The long-term effects of environmental pollution have been of concern as several pollutants are carcinogenic, potentially inducing a variety of cancers, including childhood cancer, which is a leading cause of death around the world and, thus, is a public health issue. The present scoping review aimed to update and summarize the available literature to detect specific environmental pollutants and their association with certain types of childhood cancer. Studies published from 2013 to 2023 regarding environmental pollution and childhood cancer were retrieved from the PubMed database. A total of 174 studies were eligible for this review and were analyzed. Our search strategy brought up most of the articles that evaluated air pollution (29%) and pesticides (28%). Indoor exposure to chemicals (11%), alcohol and tobacco use during pregnancy (16%), electromagnetic fields (12%), and radon (4%) were the subjects of less research. We found a particularly high percentage of positive associations between prenatal and postnatal exposure to indoor (84%) and outdoor (79%) air pollution, as well as to pesticides (82%), and childhood cancer. Positive associations were found between leukemia and pesticides and air pollution (33% and 27%); CNS tumors and neuroblastoma and pesticides (53% and 43%); and Wilms tumor and other rare cancers were found in association with air pollution (50%). Indoor air pollution was mostly reported in studies assessing several types of cancer (26%). Further studies are needed to investigate the mechanisms underlying the potential associations between indoor/outdoor air pollution and pesticide exposure with childhood cancer risk as more preventable measures could be taken.

Risk factors for childhood brain tumours: A systematic review and meta-analysis of observational studies from 1976 to 2022

BACKGROUND

Childhood brain tumours (CBTs) are the leading cause of cancer death in children under the age of 20 years globally. Though the aetiology of CBT remains poorly understood, it is thought to be multifactorial. We aimed to synthesize potential risk factors for CBT to inform primary prevention.

METHODS

We conducted a systematic review and meta-analysis of epidemiological studies indexed in the PubMed, Web of Science, and Embase databases from the start of those resources through 27 July 2023. We included data from case-control or cohort studies that reported effect estimates for each risk factor around the time of conception, during pregnancy and/or during post-natal period. Random effects meta-analysis was used to estimate summary effect sizes (ES) and 95% confidence intervals (CIs). We also quantified heterogeneity (I2) across studies.

FINDINGS

A total of 4040 studies were identified, of which 181 studies (85 case-control and 96 cohort studies) met our criteria for inclusion. Of all eligible studies, 50% (n = 91) were conducted in Europe, 32% (n = 57) in North America, 9% (n = 16) in Australia, 8% (n = 15) in Asia, 1% (n = 2) in South America, and none in Africa. We found associations for some modifiable risk factors including childhood domestic exposures to insecticides (ES 1.44, 95% CI 1.20-1.73) and herbicides (ES 2.38, 95% CI 1.31-4.33). Maternal domestic exposure to insecticides (ES 1.45, 95% CI 1.09-1.94), maternal consumption of cured meat (ES 1.51, 95% CI 1.05-2.17) and coffee ≥ 2 cups/day (ES 1.45, 95% 95% CI 1.07-1.95) during pregnancy, and maternal exposure to benzene (ES 2.22; 95% CI 1.01-4.88) before conception were associated with CBTs in case-control studies. Also, paternal occupational exposure to pesticides (ES 1.48, 95% CI 1.23-1.77) and benzene (ES 1.74, 95% CI 1.10-2.76) before conception and during pregnancy were associated in case-control studies and in combined analysis. On the other hand, assisted reproductive technology (ART) (ES 1.32, 95% CI 1.05-1.67), caesarean section (CS) (ES 1.12, 95% CI 1.01-1.25), paternal occupational exposure to paint before conception (ES 1.56, 95% CI 1.02-2.40) and maternal smoking > 10 cigarettes per day during pregnancy (ES 1.18, 95% CI 1.00-1.40) were associated with CBT in cohort studies. Maternal intake of vitamins and folic acid during pregnancy was inversely associated in cohort studies. Hormonal/infertility treatment, breastfeeding, child day-care attendance, maternal exposure to electric heated waterbed, tea and alcohol consumption during pregnancy were among those not associated with CBT in both case-control and cohort studies.

CONCLUSION

Our results should be interpreted with caution, especially as most associations between risk factors and CBT were discordant between cohort and case-control studies. At present, it is premature for any CBT to define specific primary prevention guidelines.

Caffeine intake during pregnancy and adverse outcomes: An integrative review

Caffeine intake during pregnancy is common. Caffeine crosses the placenta, raising concerns about its possible deleterious effects on the developing embryo/fetus. Studies on this subject show conflicting results, and still there is no consensus on the recommended dose of caffeine during pregnancy. We performed an integrative review with studies from six databases, using broad MESH terms to allow the identification of publications that addressed the outcomes of caffeine use during pregnancy, with no date limit for publications, in English and Portuguese language. The research returned 16,192 articles. After removing duplicates, screening by title, abstract and full-text, we evaluated 257 and included 59 articles. We found association between caffeine intake and pregnancy loss, low birth weight, cardiac and genital anomalies, higher body mass, and neurodevelopmental and neurobehavioral outcomes. The effects were often dose dependent. No association with prematurity has been demonstrated, but one study showed a small reduction in gestational age with increasing doses of caffeine intake. Defining a safe dose for caffeine intake during pregnancy is a challenging task due to the heterogeneity in study designs and results, as well as the difficulty of reliably assessing the amount of caffeine consumed. In some studies, exposures below the recommended level of caffeine intake during pregnancy (200 mg/day), as suggested by the guidelines, were associated with pregnancy loss, low birth weight, cardiac and genital anomalies, higher body mass, and neurodevelopmental and neurobehavioral outcomes. Well-designed studies with reliable quantification of caffeine intake are needed to assess the safety of low doses during pregnancy.

Medium Roasting and Brewing Methods Differentially Modulate Global Metabolites, Lipids, Biogenic Amines, Minerals, and Antioxidant Capacity of Hawai'i-Grown Coffee (Coffea arabica)

In the United States, besides the US territory Puerto Rico, Hawai'i is the only state that grows commercial coffee. In Hawai'i, coffee is the second most valuable agricultural commodity. Health benefits associated with moderate coffee consumption, including its antioxidant capacity, have been correlated to its bioactive components. Post-harvest techniques, coffee variety, degree of roasting, and brewing methods significantly impact the metabolites, lipids, minerals, and/or antioxidant capacity of brewed coffees. The goal of our study was to understand the impact of roasting and brewing methods on metabolites, lipids, biogenic amines, minerals, and antioxidant capacity of two Hawai'i-grown coffee (Coffea arabica) varieties, "Kona Typica" and "Yellow Catuai". Our results indicated that both roasting and coffee variety significantly modulated several metabolites, lipids, and biogenic amines of the coffee brews. Furthermore, regardless of coffee variety, the antioxidant capacity of roasted coffee brews was higher in cold brews. Similarly, total minerals were higher in "Kona Typica" cold brews followed by "Yellow Catuai" cold brews. Hawai'i-grown coffees are considered "specialty coffees" since they are grown in unique volcanic soils and tropical microclimates with unique flavors. Our studies indicate that both Hawai'i-grown coffees contain several health-promoting components. However, future studies are warranted to compare Hawai'i-grown coffees with other popular brand coffees and their health benefits in vivo.

Potential role of tea extract in oocyte development

Tea is the second most popular beverage in the world and beneficial to health. It has been demonstrated that tea polyphenols can reduce the risk of diseases, such as cancers, diabetes, obesity, Alzheimer's disease, etc. But the knowledge of tea extract on the female germline is limited. Folliculogenesis is a complicated process and prone to be affected by ROS. Tea polyphenols can reduce the accumulation of ROS in folliculogenesis and affect oocyte maturation. Tea extract also influences granulosa cell proliferation and expansion during oocyte growth and maturation. However, the studies about the benefits of tea extract on female germline are few, and the underlying mechanisms are obscure. In the present study, we will mainly discuss the effects of tea extract on ovarian function, oocyte maturation, and the underlying possible mechanisms, and according to the discussion, we suggest that tea extract may have benefits for oocytes at an appropriate dose.

Coffee and tea consumption during pregnancy and risk of childhood acute myeloid leukemia: A Childhood Leukemia International Consortium (CLIC) study

BACKGROUND

Dietary habits during pregnancy have been inconsistently linked to childhood acute myeloid leukemia (AML), given the putative intrauterine onset of the disease as a result of triggering events during the critical period of fetal hematopoiesis. We investigated the potential association of maternal coffee and tea consumption during pregnancy with childhood AML risk, pooling primary data from eight case-control studies participating in the Childhood Leukemia International Consortium.

METHODS

Information on coffee and/or tea consumption was available for 444 cases and 1255 age- and sex-matched controls, on coffee consumption for 318 cases and 971 controls and on tea consumption for 388 cases and 932 controls. Categories for cups of daily coffee/tea consumption were created in order to explore potential dose-response associations. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression.

RESULTS

Associations were found neither in the analysis on coffee or tea nor in the analysis on coffee only consumption (any versus no). A positive association with increasing coffee intake was observed (>1 cup per day; OR: 1.40, 95% CI: 1.03-1.92, increment of one cup per day; OR: 1.18, 95% CI: 1.01-1.39). No associations were observed with tea consumption. Interaction analyses showed non-significant associations between coffee/tea and smoking. Hyperdiploidy was inversely associated with tea consumption, with other cytogenetic markers having no association with coffee/tea.

CONCLUSION

Given the widespread consumption of caffeinated beverages among pregnant women, our finding is of important public health relevance, suggesting adverse effects of maternal coffee consumption during pregnancy in the offspring.

Biases Inherent in Studies of Coffee Consumption in Early Pregnancy and the Risks of Subsequent Events

Consumption of coffee by women early in their pregnancy has been viewed as potentially increasing the risk of miscarriage, low birth weight, and childhood leukemias. Many of these reports of epidemiologic studies have not acknowledged the potential biases inherent in studying the relationship between early-pregnancy-coffee consumption and subsequent events. I discuss five of these biases, recall bias, misclassification, residual confounding, reverse causation, and publication bias. Each might account for claims that attribute adversities to early-pregnancy-coffee consumption. To what extent these biases can be avoided remains to be determined. As a minimum, these biases need to be acknowledged wherever they might account for what is reported.

Parental smoking, maternal alcohol, coffee and tea consumption and the risk of childhood brain tumours: the ESTELLE and ESCALE studies (SFCE, France)

PURPOSE

To investigate whether parental smoking around the time of pregnancy or maternal consumption of beverages (alcohol, coffee, or tea) during pregnancy were associated with the risk of CBT.

METHODS

We pooled data from two French national population-based case-control studies with similar designs conducted in 2003-2004 and 2010-2011. The mothers of 510 CBT cases (directly recruited from the national childhood cancer register) and 3,102 controls aged under 15 years, frequency matched by age and gender, were interviewed through telephone, which included questions about prenatal parental smoking and maternal consumption of alcohol, coffee and tea. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using unconditional logistic regression, adjusted for age, sex and study of origin.

RESULTS

No association was seen between CBT and the mother smoking or drinking alcohol, coffee, or tea during the index pregnancy. The OR between CBT and paternal smoking in the year before birth (as reported by the mother) was 1.25 (95% CI 1.03, 1.52) with an OR of 1.09 (0.99, 1.19) for every 10 cigarettes per day (CPD) smoked. The association between paternal smoking and CBT appeared to be stronger in children diagnosed before the age of five years (OR 1.52, 95% CI 1.14, 2.02) and for astrocytoma (OR 1.86, 95% CI 1.26, 2.74).

CONCLUSION

We found some evidence of a weak association between paternal smoking in the year before the child's birth and CBT, especially astrocytomas. These findings need to be replicated in other samples, using similar classifications of tumour subtypes.

Maternal and childhood consumption of coffee, tea and cola beverages in association with childhood leukemia: a meta-analysis

OBJECTIVE

To systematically review studies and meta-analyze the literature on the association of maternal and/or index child's coffee, tea, and cola consumption with subsequent development of childhood leukemia and its major subtypes.

METHODS

Eligible studies were identified through a detailed algorithm and hand-search of eligible articles' references; thereafter, summary-effect estimates were calculated by leukemia subtype and dose-response meta-analyses were performed.

RESULTS

Twelve case-control studies, comprising a total of 3649 cases and 5705 controls, were included. High maternal coffee consumption was positively associated with acute lymphoblastic leukemia (ALL; OR: 1.43, 95%CI: 1.22-1.68) and acute myeloid leukemia (AML; OR: 2.52, 95%CI: 1.59-3.57). Any or low to moderate maternal cola consumption was also positively associated with overall leukemia (AL) and ALL, A linear trend between coffee and cola consumption and childhood leukemia was observed in the dose-response analyses. On the contrary, low to moderate tea consumption was inversely associated with AL (OR: 0.85, 95%CI: 0.75-0.97), although the trend was non-significant. A null association between offspring's cola consumption and leukemia was noted.

CONCLUSIONS

Our findings confirm the detrimental association between maternal coffee consumption and childhood leukemia risk and provide indications for a similar role of maternal cola intake. In contrast, an inverse association with tea was found, implying that other micronutrients contained in this beverage could potentially counterbalance the deleterious effects of caffeine. Further research should focus on the intake of specific micronutrients, different types of coffee and tea, specific immunophenotypes of the disease, and the modifying effect of genetic polymorphisms.