Avocados are not recommended for breast cancer

Avocados (Persea americana) generally are considered a healthy food; the high fat content of avocados typically is the only reason given for limiting consumption of this fruit. Avocados are a good source of monounsaturated fats, folate, various carotenoids such as lutein and beta-carotene, and various chlorophylls. Avocados have been shown to protect the liver, improve cholesterol, and ameliorate osteoarthritis symptoms. Avocado extract has been shown to have chemopreventive effects on human oral premalignant and malignant cells, as well as inhibiting the growth of both androgen-dependent and androgen-independent prostate cancer cell lines in the laboratory. Avocados are a rich source of cytochrome P-450s, enzymes involved in drug metabolism and estrogen metabolism, the implications of which for breast cancer have not been established.

Breast cancer-related effects of eating avocados

One study found that a diet high in avocado oil promoted the formation of mammary tumors in rats. Another study of postmenopausal U.S. Latina women found that consumption of avocados was associated with higher circulating estrogen levels. On the other hand, a toxin in avocado leaves has been shown to enhance the cytotoxic effects of tamoxifen on human breast cancer cells regardless of their estrogen receptor (ER) status. Based on the available evidence, breast cancer patients, survivors and those at high risk should limit consumption of avocados until further studies clarify these findings.

Additional comments

Lactating animals that gain access to avocado leaves or fruit have been known to develop a type of noninfectious mastitis, with a marked decrease in milk production, and milk characterized by cheesy consistency and clots. This has been shown to be accompanied by pathological changes in the mammary gland. Avocado fruit and leaves have been shown to be toxic to various bird species, dogs, goats, and horses.

Up to half of people with a significant latex allergies will develop cross-reactivity to avocados.

We are aware that this is a favorite "healthy" food for many and are making an extra effort to find new studies as they become available. However, there is not much interest in avocados among cancer researchers, so few relevant studies are available.

Tags: Latina, androgens, avocadoOil, avocados, betaCarotene, carotenoids, folate, milk, tamoxifen

Selected breast cancer studies
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Stability of avocado oil during heating: Comparative study to olive oil Proliferative effects of five traditional Nigerian medicinal plant extracts on human breast and bone cancer cell lines Potential Risks Resulting from Fruit/Vegetable-Drug Interactions: Effects on Drug-Metabolizing Enzymes and Drug Transporters Avocado (Persea americana Mill.) Phenolics, In Vitro Antioxidant and Antimicrobial Activities, and Inhibition of Lipid and Protein Oxidation in Porcine Patties The multiple nutrition properties of some exotic fruits: Biological activity and active metabolites Inhibitory effects of fruit extracts on nitric oxide-induced proliferation in MCF-7 cells Medicinal plants used in Northern Peru for reproductive problems and female health In vitro evaluation of genotoxicity of avocado (Persea americana) fruit and leaf extracts in human peripheral lymphocytes Antioxidant capacities, procyanidins and pigments in avocados of different strains and cultivars Screening of antiproliferative effect of aqueous extracts of plant foods consumed in Mexico on the breast cancer cell line MCF-7 Avocado extracts selectively induce apoptosis in transformed human oral cells Chemopreventive characteristics of avocado fruit Synergistic cytotoxicity between tamoxifen and the plant toxin persin in human breast cancer cells is dependent on Bim expression and mediated by modulation of ceramide metabolism Tumor-promoting and tumor-protective effects of high-fat diets on chemically induced mammary cancer in rats Dietary fiber intake and endogenous serum hormone levels in naturally postmenopausal Mexican American women: the Multiethnic Cohort Study A novel plant toxin, persin, with in vivo activity in the mammary gland, induces Bim-dependent apoptosis in human breast cancer cells Inhibition of prostate cancer cell growth by an avocado extract: role of lipid-soluble bioactive substances Toxicopathologic studies of selected poisonous plants in southern Queensland Cytotoxic and insecticidal constituents of the unripe fruit of Persea americana