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A Special Diet for Triple Negative Breast Cancer

Posted by Manuela Boyle on 7 August 2021
A Special Diet for Triple Negative Breast Cancer
There is exciting news in the world of cancer nutrition! For years, the triple negative breast cancer patient has been without a targeted treatment. But, the evidence is beginning to show that some triple-negative specific targeted treatment is on the horizon.

This is great news for you if you want to take back the control cancer has taken from you and reduce your fear around this diagnosisyou are not powerless!

This is new information in the triple-negative breast cancer community and it will help you to be an active participant in your cancer treatment and get you on your way to thriving after cancer.

A cancer is called Triple Negative when the pathologist's tests determine that the cells from the biopsy are negative for estrogen receptors, negative for progesterone receptors, and negative for HER-2/neu receptors aka "triple negative".

Is Triple Negative Cancer Harder to Treat?

The type of cancer cell found in Triple Negative Breast Cancer is more common in women with BRCA1 gene mutations, younger women, African-Americans and Hispanics.

Triple Negative Breast Cancer makes up about 15% of breast cancer cases and is more difficult to treat because it lacks a specific target.

Since it is more difficult to treat, people with this diagnosis can be especially fearful and also feel there isn't much they can do to help themselves fight against this cancer.

I want to share some information about recent studies and scientific evidence to show you that triple negative patients may not be as powerless as they once thought.

Can Diet Help Triple Negative Breast Cancer?

A new diet that uses methionine depletion is being tested as a possible target for triple negative cancers.

Methionine is an amino acid that is part of our diet. Researchers at the University of Wisconsin conducted experiments to see how cancer behaves when this amino acid is removed from the diet.

Let me say first that this study was conducted in a laboratory with triple negative breast cancer cells in a petri dish. The study was not performed on people. But based on the results of the lab study, a clinical trial is underway to do just that.

What Happens When Breast Cancer Cells are Deprived of Methionine?

Researchers at the University of Wisconsin worked with triple negative breast cancer cells, growing these cells in 1 of 2 different cultures in the lab.

One normal culture, called a "control" and one culture that was deficient in the amino acid, methionine. Three different cell types (MDAMB-468, GILM2 and MDA-MB-231) were treated with seven different cancer drugs including lexatumumab.

The cell culture that was deficient in the amino acid, methionine, was found to be moderately toxic to the cancer cells and inhibited their proliferation.

The combination of growing cancer cells in the methionine deficient culture plus the drug lexatumumab was the only combination that showed enhanced cancer cell toxicity in all three cancer cell types.

A second experiment in which a methionine degrading enzyme (methioninase) showed that this also made lexatumumab more effective.

What Does This Mean for Me?

Since restricting methionine for isolated cancer cells is toxic, restricting methionine from the diet of a cancer patient could help to kill cancer cells, reduce their proliferation and make the drug lexatumumab more effective.

The next step to testing this hypothesis is an animal model.

Results of the Mice Study

All three treatments: methionine-free diet alone, lexatumumab alone and methionine-free diet plus lexatumumab all inhibited tumour growth compared to the control group.

The best result though was in the mice given the combination of the methionine-free diet plus lexatumumab.

This group of mice (given methionine-free diet plus lexatumumab) also had less lung metastasis. In fact, the methionine-free diet plus lexatumumab combination was even better at reducing metastases than it was at inhibiting the tumor growth.

What Do These Studies Mean For Me as a Triple Negative Breast Cancer Patient?

The University of Wisconsin researchers state in the publication of the research that "our findings provide proof-of-principle preclinical evidence to support a clinical trial combining dietary methionine restriction and [cancer drugs].

As of the writing of this post 3 trials are currently recruiting subjects.

I will be monitoring for the published version of these studies and will share the information with you. These results are very promising especially for the triple negative breast cancer community that is currently without a targeted therapy.

To stay up to date on the latest information and research that will help you to use nutrition to compliment your cancer treatment, keep reading our blods!

Should I Go On A Methionine-Free Diet?

It's too early in the research process to prescribe a methionine-free diet for triple negative breast cancer patients with confidence. However, a study was performed on eight patients with metastatic cancer done to test whether a methionine-free diet might be safe.

The patients were given a very low protein, low methionine diet for an average of 17 weeks and it was found to be safe 

What if I Want to Follow a Low Methionine Diet?

I certainly understand if you as a cancer patient or survivor do not want to wait for a clinical trial to finish and the results to be published. I know many of you want to be actively fighting against your cancer and doing everything you can.

So, I want to provide you with some additional information about methionine and a low methionine diet.

Since studies have shown a low methionine diet is safe and we know plant-based diets are safe and healthy, following a low methionine diet could be just what you need to help you feel that you are doing more to help reduce your cancer and it's spread.

By actively participating in your care in this way, it can help to give you back some control and reduce some of your fear.

What is Methionine?

Methionine is an essential amino acid. These are the building blocks of protein that we must consume in our diet in our to maintain our health. It is 'essential' meaning that we can't make it in our bodies, but must consume it in our diet.

What Foods Contain Methionine?

The top 100 methionine containing foods are all animal proteins. Turkey has 1.5 g of methionine per 90 g serving followed by (in descending order) eggs, cottage cheese, beef, chicken,  veal, tuna, pork, and  lamb.

Are you strugling with your diet? Ask us!



Methionine Deprivation Induces a Targetable Vulnerability in Triple-Negative Breast Cancer Cells by Enhancing TRAIL Receptor-2 Expression Clin Cancer Res. 2015 Jun 15;21(12):2780-91. Strekalova E1 et al.

Nutrient intake and nutritional indexes in adults with metastatic cancer on a phase I clinical trial of dietary methionine restriction. Nutr Cancer. 2002;42(2):158-66. Epner DE et al.

Author:Manuela Boyle
Tags:NewsPrevention & RecoveryEvidence Based ResearchDiets & RecipesCancerTriple negative breast cancer


  • The Institute for Functional Medicine
  • Society for Integrative Oncology
  • American Society of Clinical Oncology
  • Australian Traditional-Medicine Society
  • Naturopaths and Herbalists Association of Australia