Green Tea

Summary of Use during Lactation

Green tea (Camellia sinensis) contains caffeine, polyphenols (e.g., quercetin), and tannins. Fussiness, jitteriness and poor sleep patterns have been reported in the infants of mothers with very high caffeine intakes (see the LactMed record on caffeine for details). Giving tea directly to infants can interfere with iron absorption and cause anemia,[1] but anemia in breastfed infants has not been reported with maternal tea ingestion. Application of wet tea bags to the nipples has been studied as a method of reducing nipple pain during the first few days of nursing. Two small, moderately well-controlled studies found a positive effect of the tea bags, but warm water compresses were as at least as effective as tea bags.[2,3] No studies were found that examined the use of oral green tea extract, topical application of green tea extract to the nipples, or to the topical product Veregren applied to genital warts during breastfeeding. Topical products applied away from the breast should pose negligible risk for the breastfed infant. Green tea is reportedly used to increase milk supply by some mothers in Türkiye.[4]

Dietary supplements do not require extensive pre-marketing approval from the U.S. Food and Drug Administration. Manufacturers are responsible to ensure the safety, but do not need to prove the safety and effectiveness of dietary supplements before they are marketed. Dietary supplements may contain multiple ingredients, and differences are often found between labeled and actual ingredients or their amounts. A manufacturer may contract with an independent organization to verify the quality of a product or its ingredients, but that does not certify the safety or effectiveness of a product. Because of the above issues, clinical testing results on one product may not be applicable to other products. More detailed information about dietary supplements is available elsewhere on the LactMed Web site.

Drug Levels

Caffeine is excreted into breastmilk. Refer to the LactMed record on caffeine for details. No components of green tea besides caffeine have been measured in milk after its ingestion, but some have been measured after the ingestion of other foods.

Maternal Levels. Quercetin can be found in breastmilk of mothers with normal diets.[5] Milk samples from 17 nursing mothers on uncontrolled diets were taken at 1, 4 and 13 weeks postpartum at times between 10 am and 1 pm. Average quercetin levels in breastmilk were 48 nmol/L at week 1, 60 nmol/L at week 4 and 51 nmol/L at week 13. Because of the uncontrolled diet and varying sampling times, the range of values among individuals was large.[6]

Quercetin was measured in the milk of 11 mothers after they received an onion soup that contained either 0.8 or 1 mg/kg of quercetin glucosides. A baseline milk sample was obtained after a 5-day low-quercetin diet, and 7 milk samples were obtained over the 48 hours following soup ingestion. Baseline total (from conjugated and unconjugated) quercetin in breastmilk averaged 45 nmol/L. An average peak milk quercetin level of 68 nmol/L was attained at an average of 11.9 hours after the soup meal. The average half-life of quercetin in breastmilk was 50.3 hours.[7]

Infant Levels. Relevant published information was not found as of the revision date.

Effects in Breastfed Infants

Relevant published information was not found as of the revision date.

Effects on Lactation and Breastmilk

Relevant published information was not found as of the revision date.

References

1.

Merhav H, Amitai Y, Palti H, et al. Tea drinking and microcytic anemia in infants. Am J Clin Nutr 1985;41:1210-3. [PubMed: 4003328]

2.

Buchko BL, Pugh LC, Bishop BA, et al. Comfort measures in breastfeeding, primiparous women. J Obstet Gynecol Neonatal Nurs 1994;23:46-52. [PubMed: 8176527]

3.

Lavergne NA. Does application of tea bags to sore nipples while breastfeeding provide effective relief? J Obstet Gynecol Neonatal Nurs 1997;26:53-8. [PubMed: 9017547]

4.

Kaygusuz M, Gümüştakım RŞ, Kuş C, et al. TCM use in pregnant women and nursing mothers: A study from Turkey. Complement Ther Clin Pract 2021;42:101300. [PubMed: 33412511]

5.

Williamson G, Clifford MN. A critical examination of human data for the biological activity of quercetin and its phase-2 conjugates. Crit Rev Food Sci Nutr 2024:1-37. [PubMed: 38189312]

6.

Song BJ, Jouni ZE, Ferruzzi MG. Assessment of phytochemical content in human milk during different stages of lactation. Nutrition 2013;29:195-202. [PubMed: 23237648]

7.

Romaszko E, Wiczkowski W, Romaszko J, et al. Exposure of breastfed infants to quercetin after consumption of a single meal rich in quercetin by their mothers. Mol Nutr Food Res 2014;58:221-8. [PubMed: 23963751]

Substance Name

Green Tea

Scientific Name

Camellia sinensis

Drug Class

Breast Feeding

Lactation

Milk, Human

Complementary Therapies

Food

Phytotherapy

Plants, Medicinal