Moderate tea consumption, defined as less than 2 cups per day, was found to significantly reduce the risk of female infertility, while coffee and caffeine intake had no significant impact, according to a recent study.

A cross-sectional study published in Reproductive Biology and Endocrinology investigated the association between tea, coffee, and caffeine consumption and female infertility. The researchers analyzed data from 2,099 women aged 18 to 44 years who participated in the National Health and Nutrition Examination Survey from 2013 to 2018. The study included 236 participants in the infertility group and 1,863 participants in the fertile group.

Participants in the infertility group were older on average (33.29 years compared to 30.01 years; P < .0001). They also had a higher mean BMI (32.12 kg/m² vs. 28.54 kg/m²; P = .0006), engaged in more physical activity (1,474.22 minutes per week vs. 1,083.55 minutes per week; P = .0365), and consumed more caffeine (129.03 mg/day vs. 98.32 mg/day; P = .0379). Additionally, the infertility group had higher rates of hypertension (16.89% vs. 9.87%; P = .0176) and diabetes (8.13% vs. 2.59%; P < .0001).

The study utilized generalized linear models and generalized additive models to assess the dose-response relationships between tea, coffee, and caffeine consumption and infertility, adjusting for confounders including age, race, body mass index (BMI), education level, physical activity, and dietary intake.

The analysis identified a non-linear association between tea consumption and infertility, with an inflection point at 2 cups per day. Women consuming less than 2 cups of tea daily had a significantly lower risk of infertility (odds ratio [OR], 0.73; 95% CI, 0.57-0.93; P = .0122). Within this range, each additional cup of tea consumed was associated with a 27% reduction in the risk of infertility. No significant association was observed for those consuming more than 2 cups daily.

The study found no significant associations between coffee consumption (OR, 0.96; 95% CI, 0.81-1.13; P = .6189) or caffeine intake (OR, 1.15; 95% CI, 0.93-1.42; P = .2148) and female infertility.

Subgroup analyses considering various factors such as age, BMI, total exercise time, marital status, smoking status, and drinking status were conducted. The findings were consistent across all these subgroups.

The potential mechanisms behind the observed association between tea consumption and reduced infertility risk may involve the antioxidant properties of tea polyphenols, which could enhance egg viability and reduce cellular damage in reproductive organs. However, the quantity of water used for brewing tea was not accounted for in the analysis, which could be a potential limitation.

The findings indicated that moderate tea consumption may be associated with a reduced risk of female infertility, while coffee and caffeine intake do not show significant effects. The role of non-caffeine components in tea in reproductive health requires further investigation.

The cross-sectional nature of the study precludes causal inference. Additionally, the findings are based on a U.S. population, which may limit generalizability to other populations.

The authors reported no potential conflict of interest.