Limit or avoid during aromatase inhibitor treatment - foods

Last updated: August 27, 2025

Foods to limit on aromatase inhibitors

The current webpage is designed to make additional research available concerning how certain foods and beverages or their major bioactive components can interfere with or reduce the beneficial treatment effects of aromatase inhibitors. At the bottom of this webpage are links to studies relating to the foods under limit or avoid in Foods to eat & avoid during aromatase inhibitor treatment.

Foods and beverages can reduce the beneficial treatment effects of aromatase inhibitors, worsen their side effects, or otherwise interfere with treatment based on the following:

Increases aromatase (all types of alcohol, sesame seeds & sesame oil)
Estrogenic compounds produced during cooking (grilled, BBQ'd, or smoked meat or fish)
Potential cytochrome P450 interactions (açaí berries, grapefruit, limes, orange pith & peel, pomelos)
Incorporates zeranol growth promoter (found in non-organic beef and lamb)

Selected breast cancer studies

The Cytochrome CYP4 in Breast and Other Cancers Cite
Calaf GM, Crispin LA, Ossandon-Acosta F, Perez-Tapia S, Ardiles LN. The Cytochrome CYP4 in Breast and Other Cancers. Biology. MDPI AG; 2025; 14:812 10.3390/biology14070812
Effect of daily alcohol intake on sex hormone levels among postmenopausal breast cancer survivors on aromatase inhibitor therapy: a randomized controlled crossover pilot study Cite
Mostofsky E, Buring JE, Come SE, Tung NM, Zhang C, Mukamal KJ. Effect of daily alcohol intake on sex hormone levels among postmenopausal breast cancer survivors on aromatase inhibitor therapy: a randomized controlled crossover pilot study. Breast Cancer Research. Springer Science and Business Media LLC; 2025; 27 10.1186/s13058-024-01940-4
Examining dietary supplements containing Euterpe oleracea Mart. (açaí) for potential botanical-drug interactions involving CYP3A4 inhibition Cite
Heck KL, Fogel LM, Thornton D, Kunze ML, Almy M, Calderón AI. Examining dietary supplements containing Euterpe oleracea Mart. (açaí) for potential botanical-drug interactions involving CYP3A4 inhibition. Phytomedicine Plus. Elsevier BV; 2024; 4:100582 10.1016/j.phyplu.2024.100582
Daily supplement of sesame oil prevents postmenopausal osteoporosis via maintaining serum estrogen and aromatase levels in rats Cite
Hsu C, Ko P, Kwan T, Liu M, Jou I, Lin C, et al. Daily supplement of sesame oil prevents postmenopausal osteoporosis via maintaining serum estrogen and aromatase levels in rats. Scientific Reports. Springer Science and Business Media LLC; 2024; 14 10.1038/s41598-023-50453-1
Interactions between natural products and cancer treatments: underlying mechanisms and clinical importance Cite
Chan WJ, Adiwidjaja J, McLachlan AJ, Boddy AV, Harnett JE. Interactions between natural products and cancer treatments: underlying mechanisms and clinical importance. Cancer Chemotherapy and Pharmacology. Springer Science and Business Media LLC; 2023; 91:103-119 10.1007/s00280-023-04504-z
Phytochemicals That Interfere With Drug Metabolism and Transport, Modifying Plasma Concentration in Humans and Animals Cite
Gómez-Garduño J, León-Rodríguez R, Alemón-Medina R, Pérez-Guillé BE, Soriano-Rosales RE, González-Ortiz A, et al. Phytochemicals That Interfere With Drug Metabolism and Transport, Modifying Plasma Concentration in Humans and Animals. Dose-Response. SAGE Publications; 2022; 20 10.1177/15593258221120485
Phenolic and flavonoid content and in vitro inhibitory effect of some Amazonian fruit juices on CYP3A4 activity Cite
COSTA EMA, DE ANDRADE FIGUEIRA MB, CARRÃO DB, HABENSCHUS MD, OLIVEIRA ARMD, ACHO LDR, et al. Phenolic and flavonoid content and in vitro inhibitory effect of some Amazonian fruit juices on CYP3A4 activity. Acta Amazonica. FapUNIFESP (SciELO); 2022; 52:172-178 10.1590/1809-4392202103642
Dietary Supplement Use and Interactions with Tamoxifen and Aromatase Inhibitors in Breast Cancer Survivors Enrolled in Lifestyle Interventions Cite
Harrigan M, McGowan C, Hood A, Ferrucci LM, Nguyen T, Cartmel B, et al. Dietary Supplement Use and Interactions with Tamoxifen and Aromatase Inhibitors in Breast Cancer Survivors Enrolled in Lifestyle Interventions. Nutrients. MDPI AG; 2021; 13:3730 10.3390/nu13113730
Sesamol Epigenetically Induces Estrogen Receptor α Re-expression by Upregulating miR-370-3p in Estrogen Receptor α-Negative Breast Cancer Cite
Ma X, Wang J, Hu G, Chen Y, Hu X, Zhu Y, et al. Sesamol Epigenetically Induces Estrogen Receptor α Re-expression by Upregulating miR-370-3p in Estrogen Receptor α-Negative Breast Cancer. Journal of Agricultural and Food Chemistry. American Chemical Society (ACS); 2021; 10.1021/acs.jafc.1c03159
Screening for CYP3A4 inhibition and induction coupled to parallel artificial membrane permeability assay (PAMPA) for prediction of botanical-drug interactions: The case of açaí and maca Cite
Zhang Y, Rants'o TA, Jung D, Lopez E, Abbott K, Pondugula SR, et al. Screening for CYP3A4 inhibition and induction coupled to parallel artificial membrane permeability assay (PAMPA) for prediction of botanical-drug interactions: The case of açaí and maca. Phytomedicine. Elsevier BV; 2019; 59:152915 10.1016/j.phymed.2019.152915
Grilled, Barbecued, and Smoked Meat Intake and Survival Following Breast Cancer Cite
Parada H, Steck SE, Bradshaw PT, Engel LS, Conway K, Teitelbaum SL, et al. Grilled, Barbecued, and Smoked Meat Intake and Survival Following Breast Cancer. Journal of the National Cancer Institute. Oxford University Press (OUP); 2017; 109:djw299 10.1093/jnci/djw299
Zeranol stimulates proliferation and aromatase activation in human breast preadipocytes Cite
ZHONG S, LIU S, CHEN S, LIN H, WANG W, QIN X. Zeranol stimulates proliferation and aromatase activation in human breast preadipocytes. Molecular Medicine Reports. Spandidos Publications; 2016; 14:1014-1018 10.3892/mmr.2016.5293
The cooked meat-derived mammary carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) elicits estrogenic-like microRNA responses in breast cancer cells Cite
Papaioannou M, Koufaris C, Gooderham N. The cooked meat-derived mammary carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) elicits estrogenic-like microRNA responses in breast cancer cells. Toxicology Letters. Elsevier BV; 2014; 229:9-16 10.1016/j.toxlet.2014.05.021
Alcohol Promotes Mammary Tumor Development via the Estrogen Pathway in Estrogen Receptor Alpha-Negative HER2/neu Mice Cite
Wong AW, Dunlap SM, Holcomb VB, Nunez NP. Alcohol Promotes Mammary Tumor Development via the Estrogen Pathway in Estrogen Receptor Alpha-Negative HER2/neu Mice. Alcoholism: Clinical and Experimental Research. Wiley; 2011; 36:577-587 10.1111/j.1530-0277.2011.01654.x
Dietary flavones and flavonones display differential effects on aromatase (CYP19) transcription in the breast cancer cells MCF-7 Cite
Li F, Ye L, Lin S, Leung LK. Dietary flavones and flavonones display differential effects on aromatase (CYP19) transcription in the breast cancer cells MCF-7. Molecular and Cellular Endocrinology. Elsevier BV; 2011; 344:51-58 10.1016/j.mce.2011.06.024
In vitro and in vivo oxidative metabolism and glucuronidation of anastrozole Cite
Kamdem LK, Liu Y, Stearns V, Kadlubar SA, Ramirez J, Jeter S, et al. In vitro and in vivo oxidative metabolism and glucuronidation of anastrozole. British Journal of Clinical Pharmacology. Wiley; 2010; 70:854-869 10.1111/j.1365-2125.2010.03791.x
The Effect of Sesame Lignan and Flaxseed Lignan and Oil on the Growth of Human Estrogen Receptor‐Positive Breast Tumors (MCF‐7) Cite
Truan J, Chen J, Thompson L. The Effect of Sesame Lignan and Flaxseed Lignan and Oil on the Growth of Human Estrogen Receptor‐Positive Breast Tumors (MCF‐7). The FASEB Journal. Wiley; 2009; 23 10.1096/fasebj.23.1_supplement.222.4
Ethanol stimulates proliferation, ERα and aromatase expression in MCF-7 human breast cancer cells Cite
Etique N, Chardard D, Chesnel A, Merlin J, Flament S, Grillier-Vuissoz I. Ethanol stimulates proliferation, ERα and aromatase expression in MCF-7 human breast cancer cells. International Journal of Molecular Medicine. Spandidos Publications; 2004; 10.3892/ijmm.13.1.149

Selected breast cancer studies

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