Recently Aug. 2, 2019, I had a patient with severe endometriosis. She switched to all xenoestrogen FREE products from our purple sheet. Immediately, she had severe 10 out of 10 pain that lasted for several days. She said that she only had that kind of 10 out of 10 pain once a year, and then only for a day or two. She called me on the phone and emailed me frantically trying to figure out what to do. She wanted to know what was going on. She also wanted to know if this has happened before in other patients.

I told her that I was sorry she had to have so much pain. And, yes, I had seen this before in other patients. I told her that she had switched to some cosmetic or product that she thought was safe, but really was NOT safe. I advised her to switch back to all her old products. Then, add back the new products one at a time to see which product was the culprit.

After she searched on the internet and thought about the products she switched to, she came to the conclusion that the avocado oil that she was slathering on her skin was causing the problem of severe 10 out of 10 pain of endometriosis. She sent me a link to this website that claimed that avocados were not good for breast cancer.

Follow up: As of August 27, 2019, my patient has double checked her cosmetics and toiletries. She carefully eliminated all possible suspects. She still believes that the avocado oil is the culprit causing her pain of 10 out of 10. I asked if she would be willing to slather on some more avocado oil to confirm the pain. However, she did not want to put any more avocado oil on her skin.

Here is an excerpt from that article:

"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."

To be fair avocados also have some great health benefits (from the same article):

"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, vitamin B6, 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."

Here is an article about high breast cancer rates in Tanzania. Breast Cancer is the second most common cancer in the women of Tanzania.  The community is impoverished.  However, the poorest segment of the community that eats a "Fruity Diet" has a high rate of breast cancer.  The "Fruity Diet" is a diet that is characterized by a higher consumption of fish, mango, papaya, avocado and watery fruits.  It is these people that have the highest rate of breast cancer.  The authors of the article concluded that that low ratio of between polyunsaturated and saturated fatty acids (P/S ratio) of the "Fruity Diet" and "Fatty Diet" was correlated to high breast cancer rates.

I concluded that the high rate of eating avocados which seem to be a breast cancer inducing food may have caused the breast cancer.  Avocados likely contain xenoestrogens that provoke breast cancer.  I personally believe that an occasional avocado or guacamole sauce is no big deal.  However, constant eating of avocados every day may or may not create an environment to promote breast cancer.  Recently, I saw bottles of avocado oil to be used in cooking at a local warehouse club.  Maybe it is more prudent to be cooking with coconut oil instead.

I like avocados. My grandfather used to have an avocado tree in his yard in Hawaii that gave us boxes and boxes of avocados. When I was a kid, my mom used cut us an avocado to eat with dinner because it was free. I guess I am going to have to be more careful about how many avocados and guacamole sauce I eat.

Please see the following:

https://www.ncbi.nlm.nih.gov/pubmed/9066676

Research Articles:

• Acute heart failure in rabbits by avocado leaf poisoning
• Free radical scavenging and anti-proliferative activities of avocado (Persea americana Mill.) seed
• Triterpenoid of avocado (Persea americana) seed and its cytotoxic activity toward breast MCF-7 and liver HepG2 cancer cells
• Quantitative evaluation of the phenolic profile in fruits of six avocado (persea americana) cultivars by ultra-high-performance liquid chromatography-heated electrospray-mass spectrometry
• Toxicogenetic study of Persea americana fruit pulp oil and its effect on genomic instability
• The defensin from avocado (Persea americana var. drymifolia) PaDef induces apoptosis in the human breast cancer cell line MCF-7
• Microtubule-stabilizing properties of the avocado-derived toxins (+)-(R)-persin and (+)-(R)-tetrahydropersin in cancer cells and activity of related synthetic analogs
• Avocado Extract Inhibits 7, 12-Dimethylbenz[a]anthracene (DMBA)- Induced Carcinogenesis in Hamster Cheek Pouches
• Role of endoplasmic reticulum stress induction by the plant toxin, persin, in overcoming resistance to the apoptotic effects of tamoxifen in human breast cancer cells
• Novel anticancer alkene lactone from Persea americana
• Cardiotoxicity of acetogenins from Persea americana occurs through the mitochondrial permeability transition pore and caspase-dependent apoptosis pathways
• Dietary patterns and breast cancer risk among women in northern Tanzania: a case-control study
• Potential Risks Resulting from Fruit/Vegetable-Drug Interactions: Effects on Drug-Metabolizing Enzymes and Drug Transporters
• Inhibitory effects of fruit extracts on nitric oxide-induced proliferation in MCF-7 cells
• Stability of avocado oil during heating: Comparative study to olive oil
• Medicinal plants used in Northern Peru for reproductive problems and female health
• Proliferative effects of five traditional Nigerian medicinal plant extracts on human breast and bone cancer cell lines
• Antioxidant capacities, procyanidins and pigments in avocados of different strains and cultivars
• Avocado (Persea americana Mill.) Phenolics, In Vitro Antioxidant and Antimicrobial Activities, and Inhibition of Lipid and Protein Oxidation in Porcine Patties
• In vitro evaluation of genotoxicity of avocado (Persea americana) fruit and leaf extracts in human peripheral lymphocytes
• Pigments in Avocado Tissue and Oil
• Screening of antiproliferative effect of aqueous extracts of plant foods consumed in Mexico on the breast cancer cell line MCF-7
• A two-step screening method, using estrogen receptor-mediated transactivation, to measure estrogenicity in edible plants
• Selective Induction of Apoptosis of Human Oral Cancer Cell Lines by Avocado Extracts Via a ROS-Mediated Mechanism
• Isolation and identification of a compound from avocado (Persea americana) leaves which causes necrosis of the acinar epithelium of the lactating mammary gland and the myocardium
• A novel plant toxin, persin, with in vivo activity in the mammary gland, induces Bim-dependent apoptosis in human breast cancer cells
• Chemopreventive characteristics of avocado fruit
• Cytotoxic and insecticidal constituents of the unripe fruit of Persea americana
• Inhibition of prostate cancer cell growth by an avocado extract: role of lipid-soluble bioactive substances
• Dietary fiber intake and endogenous serum hormone levels in naturally postmenopausal Mexican American women: the Multiethnic Cohort Study
• 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
• Avocado extracts selectively induce apoptosis in transformed human oral cells
• https://aacrjournals.org/cancerpreventionresearch/article-abstract/16/4/211/718840/Prospective-Study-of-Avocado-Consumption-and?redirectedFrom=fulltext