The Best Diet For HER2 Positive Breast Cancer

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The Best Diet For HER2 Positive Breast Cancer

Continuing my series of articles on dietary recommendations for particular types of breast cancer, this one is for those of you who have been diagnosed with HER2 Positive (HER2+) breast cancer.

What Exactly is HER2 Positive Breast Cancer?

HER2 positive refers to a type of breast cancer that overexpresses the HER2/neu gene. About 15-20% of breast cancers are HER2+, meaning the cancer is fueled by over-production of the human epidermal growth factor receptor 2 protein.  HER2+ breast cancers contain excess copies of this gene, leading to dramatically more HER2 protein on the surface of cancer cells.  Because of this protein, which produces signals that tell the cells to grow, they do so out of control, causing this form of breast cancer.

Many women are told that a HER2+ diagnosis is associated with a significantly higher chance of local breast cancer recurrence (that means the cancer often returns in the same breast as the original tumor). Before the late 1990s, women with HER2+ breast cancer had poorer survival rates. Today, however, because of targeted therapies like Herceptin, this is no longer the case and it is a much more treatable disease.  Herceptin works by attaching to HER2 receptors on cancer cells, blocking signals that cause growth, and alerting the immune system to destroy the cancer.

Can Diet Make A Difference?

Please know that there are plenty of things you can eat and supplements you can take which will make a big difference for you and will assist your return to wellness.

Research shows that there are some foods and spices that are especially potent in inhibiting HER2+ breast cancer cell growth and proliferation and in promoting the process known as apoptosis (programmed cell death).  In addition, some foods have been found to amplify the effects of Herceptin.

Food That You Should Include In Your Diet If You Have HER2+ Breast Cancer

Wherever possible, try to ensure that the items from the list below are organic, because if you are trying to heal from cancer you need to stay away from conventionally grown produce and meats as much as possible due to the pesticide and herbicide residues.  You really need to keep the toxin load at a minimum to give your body a better chance to heal.

Here’s the list of foods and spices (or their components) which have been found to inhibit the growth or proliferation of HER2+ breast cancer cells. Many of these things also help to counteract the toxicity of Herceptin:

bell peppers (capsicum), black pepper, blueberries, red cabbage, green cabbage, cauliflower, bok choy/Chinese cabbage, broccoli, brown rice, Brussels sprouts, purple carrots, cherries (particularly sour cherries), celery, cranberries, red grapes, green tea, horseradish, herring, hot peppers, lake trout, mackerel, mustard and mustard greens, extra virgin olive oil, red onions, parsley, pomegranates, raspberries, black rice, wild caught salmon, sardines, tomatoes, turmeric, turnips and turnip greens, walnuts, watercress. See also my article Study Shows Curcumin Works as Well as Herceptin In Some Cases.

This is not an exhaustive list – indeed, there are many other foods which are known to have anti-cancer benefits – but this is the list that we have research for which indicates a potent anti-HER2+ activity. See my page Diet and Cancer for a list of other foods that have anti-cancer activity.

I recommend that breast cancer patients and survivors with HER2+ breast cancer include as many of the things on the “good” list above and limit or avoid the “please avoid” things that appear below.

Please Avoid These

No food list is complete without mentioning the things that should be avoided for HER2+ breast cancer because they have been shown to promote HER2+ breast cancer growth or increase HER2+ expression. Those things are: alcohol, folic acid supplements, genistein supplements, grapefruit, the Chinese herb ligusticum chuanxiong, the Chinese herb Si-Wu-Tang (may interfere with the effectiveness of Herceptin), soy protein isolate, cigarette smoking.

Foods That Assist the Effects of Herceptin

The following foods have been found to assist the effects of Herceptin against HER2+ breast cancer:

açaí berries, blackberries, boysenberries, cherries (particularly sour or tart), blackcurrants, cruciferous vegetables (broccoli, cabbage, cauliflower, kale, Brussels sprouts etc), flaxseed, green tea, extra virgin olive oil, passion fruit, purple or red plums, pomegranates, black raspberries, black or purple rice, strawberries, purple sweet potatoes, walnuts

There are also quite a number of essential oils and other supplements which research has indicated are helpful against HER2 positive breast cancer so be sure to check out those resources on my website.

Thanks for some of the dietary recommendations in this article goes out to – written by Sarah Charles, also a breast cancer survivor and a woman of sharp intellect, Sarah has a mathematics degree from UCLA and is a Harvard graduate.

GET MY BEST TIPS on getting through breast cancer and preventing recurrences by signing up for my free e-newsletters and e-books on the right.  You can also “like” me on Facebook (Marnie Clark, Breast Health Coach) to get my inspirational snippets, news and updates.  I promise to do my utmost to keep you informed and empowered on your healing journey… and beyond.  

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56 thoughts on “The Best Diet For HER2 Positive Breast Cancer

  1. Hi
    Your article is very helpful. I’m HER2 triple positive. I have a hard time in determining what foods to eat. I miss the sugar is coconut Palm sugar something I could eat or avoid. I know I need to avoid red meat. Is there a book of recipes or guideline I can use.
    My doctor said to eat organic food and avoid foods with hormones and soy. I’ve lost so much weight because I am not sure on foods to eat.

    1. Irma,
      I have responded to you privately, I hope that you received my email. Thanks for your comment on my web article and let me know if I can help you further.
      Warmest regards,
      Marnie Clark

  2. Dear Marnie, thanks for the reminders. I am approaching my three years from diagnosis mark (h2+, ER+) and am so appreciative of the advice and news in your blog. You have provided a valued source of information and support through those years, as I continue to recover from the effects of treatment and try to stave off recurrance.

    1. Dear Jeanie,
      Congratulations on three years! I am so happy to hear that you have found my information and support to be helpful. I wish you all the best and if I can help you with your healing plan to keep away recurrences, just let me know. I’d be happy to assist you.
      Warmest regards,
      Marnie Clark

      1. Hi Marmie,

        I would need need your help with my healing plan to keep away recurrences.
        I really appreciate the fact that you are so willing to help.
        Thank you so much

        1. Hi Rita,
          Thanks for your comment and I apologize for the delay in responding. I’ve been moving and was without Internet (I know, really?) for a whole week. I see you have signed up for my newsletters so I have loads of help coming your way. Be sure to let me know if you need some coaching.
          Warmest wishes,

  3. Dear Marnie,

    Thanks for your information. I am her2 positive. Is soy products good? I am thinking of taking vitamins is that good? Chia seeds and bilberry tablets? Any other do’s and dont’s with her2 positive. Thank you


    1. Please help, I have the same question as Rita in the above
      Thanks for your information. I am her2 positive. Is soy products good? I am thinking of taking vitamins is that good? Chia seeds and bilberry tablets? Any other do’s and dont’s with her2 positive. Thank you

      1. Vanes,
        I apologize for the delay in responding. I’ve got loads of email and am just working my way through it as I can. My best suggestion is that you follow the recommendations on this page for the best diet for HER2 positive breast cancer. Soy products can be good, just stay away from anything that says “soy protein isolate” as it is associated with a higher risk for breast cancer. Whole soy foods in general – in moderation – are okay. Some vitamins are helpful, some are not. Chia seeds are great. I would suggest you sign up for my newsletters and information, given freely to share with people the best ways to heal from breast cancer and keep away recurrences. You can sign up from any page on my website.
        Warmest regards,
        Marnie Clark

  4. Are the above foods also good for triple positive breast cancer or only HER2 positive. Also I have heard that turmeric interact with Femara, is that true?

    1. Hi Refjola,
      I apologize for the delay in responding to you – I do try to walk away from my computer on the weekends and I knew your question would require some research. To answer your first question, yes this list of foods is good for those with triple positive breast cancer. Re the turmeric interaction with Femara, that’s an easily asked question but not so easily answered and I will attempt to be brief. Aromatase inhibitors are metabolized in the body by certain liver enzymes, so anything that interfered with these enzymes would change how the aromatase inhibitors would act in the body. To my knowledge, Femara acts to inhibit the activity of enzymes CYP2A6 and CYP2C19. In one study, curcumin actually worked well in combination with Femara to inhibit growth of tumors (see this 2010 study: Tamoxifen and Aromasin, two more aromatase inhibitors, do appear to be affected by curcumin, more info here: I hope that answer makes sense to you but be sure to check with your doctor if you are worried.

  5. Hi, I have HER-2 breast cancer, and am currently in the midst of chemotherapy with Taxitir, Herceptin, and Pergeta (spellings?) My question is this: I see lot about not taking “anti-oxidant vitamins,” but what about, for example, Trader Joes “super-anti-oxidant green tea?” I have been drinking that every day, thinking it is doing me good, and now I am wondering. I have always been a die-hard coffee-drinker, so to boot, this introduction to tea has been a real “sacrifice.” 🙁 Thank you for any light you can shed on this.

    1. Hi Christine,
      Thanks for the great question. I have just sent you an email explaining more about antioxidants for cancer patients, a hotly debated subject! Keep drinking the green tea, it is great for you, just make sure it’s organic.
      Warmest regards,

        1. Melanie,
          A very good source of information regarding the taking of antioxidants along with chemotherapy comes from Integrative Oncologist, Dr Brian Lawenda. Here is his article on the subject: Yes, he is discussing taking antioxidants during chemotherapy and radiation, not necessarily Herceptin. I haven’t seen any recent studies which discuss the safety of taking antioxidants with Herceptin so it’s always good to consult with your doctor or naturopath. The studies I have seen coming through relate to flaxseed oil and how it assists the Herceptin to do its job. Here is my article on the subject:
          I hope this info helps –

          Best regards,
          Marnie Clark

        2. Dear Mamie, I have just recently been diagnosed with Her2+ Breast Cancer w 1 lymph node. My first Chemo day is two days from now. There is no family history. I am suppose to have 4 mints of Chemo. One every 3 weeks then surgery. Stage 2 to 3.
          I will be 62 in two weeks.
          This diagnosis has put a stop to my life as I know it.
          I am divorced with three grown children who have lives of their own.
          Do you believe that blunt force trauma to the breast such as being kicked in that same spot could have caused this?

          1. Hi Nina,
            I’m sorry to hear of your diagnosis, but please know that YOU CAN BEAT THIS! It’s truly important that you realize this, first and foremost. This is going to be a rather large bump in the road, but will not stop your life, not if you are a proactive patient and do some really good things for yourself (things that I can teach you via this website and my newsletters). Re the blunt force trauma, there is no way to know whether or not this caused your problem. There are so many factors involved with the development of breast cancer. Are you a subscriber to my newsletters? They are full of my best information on healing from breast cancer and avoiding recurrences and I have just updated them with the latest info and research. You can sign up from any page on my site, if you haven’t already done so. Here is my page explaining more: I look forward to hearing from you.
            Warmest regards,
            Marnie Clark

  6. Hi! Thank you for all the good info on this site!
    My question, I’m a 34 year old and battling a very aggressive hormone receptor negative, her2+ diagnosis. Had chemo, surgery, radiation and now finishing up the 1 year of herceptin. Yesterday read about grapefruit interactions with some drugs, including cancer drugs and my heart sank 🙁 after surgery I’ve been trying to juice almost every day and grapefruit is my go to ingredient to sweeten and add some zest to the veggie juices. Have you heard of grapefruit interactions with herceptin?
    Thank you!
    PS I’ve been dealing with urinary track infections that won’t go away after several cycles of antibiotics and sstarting to think grapefruit might be the explanation!

    1. Hi there – great question. Check your email, I’ve just sent you a private response because I had a lot to say on the subject! For anyone else out there, please do avoid grapefruit if you are taking Herceptin. We don’t have conclusive studies that indicate grapefruit interferes with Herceptin, but we do know that grapefruit interferes with many drugs, so it’s best to avoid it while you are on Herceptin.
      Warmest regards,

  7. Hi-I’m just thru chemo a few months (TCHP) so Herceptin and Pergeta (HER2+/neg/neg) and am worried about my liver. Prior to diagnosis had low cortisol and now my ferritin is low–this DESPITE having hemochromatosis. So, I’m concerned several of my blood counts are not only wacked-but are also volatile (Iron was high a few months ago). I was genetically diagnosed to have hemochromatosis. Was looking at Milk Thistle to cleanse and repair my liver and see here you recommend NOT taking it. Why?

    1. Hi Lisa,
      I apologize for the delay in responding to you, I’ve been away for a short break. To answer your question, a 2006 study on rats indicated that milk thistle actually promoted the growth of HER2 positive cancer – here is the study: While it is not conclusive, and it may not happen in humans, better to be safe than sorry at this stage. I hope that helps you, and please feel free to subscribe to my free newsletters, full of all my best information on healing from breast cancer.
      Warmest regards,

  8. Hello Marnie, this is such useful information. Thank you. I was first diagnosed with Her2 triple positive breast cancer in 2001 – 6 of 15 nodes were affected – had a lumpectomy and aggressive treatment. In 2008, a routine mammogram picked up a small speck and on biopsy it was again an her2 breast cancer. I decided on a mastectomy, 4 rounds of chemo and a year of herceptin. Last week, I was diagnosed with it again- this time in a lymph node on my chest (subcarinal). I’m waiting to hear what the treatment will be but I guess it’ll be chemo and herceptin again. To add to the pain, I have a gastric lymphoma which will also require treatment. In the past year I’ve been so stressed at work and have been drinking a couple of glasses of wine most nights – could it really have been this that has seen the return of this persistent beast?

    1. Hi Denise,
      I’ve just replied to you via email. For the benefit of my readers, I will just say that stress and alcohol are definitely risk factors for cancer so getting these under control would be a good place to begin. Please read my email and if I can help you, let me know.
      Warmest regards,
      Marnie Clark

  9. hello, I had her2er/pr + breast cancer,stage 3b. I had 3 chemo drugs and Herceptin, but had to stop the Herceptin because of heart valve problem. I am 64 years old and I cannot take any hormone therapy. can you suggest anything that might help?

    1. Hi Mary,
      Thanks for your comment on my website. I apologize for the delay in responding to you. I’ve been away. I will send you a private email with some information that may be helpful to you.
      Warmest regards,

  10. Thank you for your help in understanding Her 2+ breast cancer. I had stage 2 Her 2+ breast cancer which was removed in April, 2014. I went had the recommended chemo and radiation treatments, and I finished Herceptin treatments in July, 2015. I try to avoid all foods that might cause it to return. I have concerns about how effective Herceptin has been in preventing the return of this cancer. Do you know the most recent information on this? I appreciate the recommendation on foods to avoid. I also use essential oils. At this point, I am avoiding anything that relates to homone balancing such as lavender and tea tree oil. Thanks for any insight on this as well.

    1. Hi Talitha,
      I can definitely understand your concern about the effectiveness of Herceptin. I have written a couple of articles about it, see (written 2/18/14) and (written 5/22/15). Too bad there are no research studies on HER2+ breast cancer showing what a particular sort of diet and very specific supplements can do – but I’m here to tell you that they can make a wonderful difference. Oh and by the way – that information you found on the Internet about the estrogenic properties of lavender and tea tree oil are just plain WRONG. It’s my experience that if a person is using good quality, organic essential oils (meaning they don’t have any toxic chemical residue in them – some brands do) there is no need to worry. The problem is that there are all kinds of essential oils out there that have not been properly distilled or were distilled using toxic chemicals. Know your source and you should be fine. Let me know if I can help you. Have you signed up for my free newsletters and e-books?
      Warmest wishes,
      Marnie Clark

  11. Hi there,

    Have just been diagnosed HER2 3+. Had my left sentinel lymphnode dissection done yesterday. Supposed to insert a port today but failed cos there was only one vessel available. Next Tue doc will try the left arm, and we will see the doc again on 22 Feb to speak about the lymphnode result and if all is clear, schedule for chemo.

    I’m googling around for recipe on what I can eat once my chemo starts so that my mother-in-law can help me prepare on days where i cannot.

    Pls help.

    Thank you.

    Flora M.

    1. Flora,
      I have just emailed you and sent you the link to my articles on juicing – that’s the best thing I can recommend for someone going through chemotherapy. Juicing provides you with all of the nutrients your body requires, it’s easy to digest, it helps you to detox along the way, it provides energy at the cellular level, it’s one of the best things you can do for yourself. You might also like to subscribe to my newsletters. I will send you a link.
      Warmest wishes,

      1. Hi Marnie,
        Is coffee ok to drink? I am on Letrizole, will juicing help hair loss and what to juice? I also take Stevie by Kal.

  12. Hi Marnie
    Thank you for the blog,I have gained insight and answers to many unanswered questions.

    I am Her 2 3+,had surgery,completed chemotherapy and six weeks radiotherapy. Doctors request for Herceptin has been declined by the medical aid and I am overwhelmed at present as I fear the prognosis without Herceptin administration.

    What is the possible case scenario without herceptin?
    Is there anything I can do as a patient in pleading my case to the Medical Aid.
    Any advise will be appreciated.

    1. Dear Cynthia,
      I apologize for the delay in responding to you. You are quite welcome and please let me know if I can assist you.
      Warmest regards,
      Marnie Clark

  13. Hi Marnie, I was diagnosed with Her2 + and the other two were negative and this cancer is inflammatory. I did chemo, double mastectomy (they moved my back muscle to my chest and put expanders in), radiation and then got an infection and the cancer returned in my chest skin and is now metastatic. I am trying hard to give up alcohol. Is any safe? Thank you for this guidance! I just found this and will start this diet tomorrow. I don’t want to die yet. They had me on Herceptin and when the cancer returned, they added TDM1 to it. I pray this is working. I get my fourth pet scan this week.

  14. Hi Marnie,

    Please help me if grapefruit is not good for me, I am a Stage 1 her2 postive…. and loveeating grapefruits as part of my healthy diet… also I am a coffee drinker… Im glad i found this site. Thank you for your heartfull help. God bless you.

    1. Dona Jean,
      Sorry for the long delay in responding to you (pressing family matters!). I think you may want to stop eating grapefruit while you are fighting breast cancer. It apparently interferes with an enzyme system which helps to metabolize estrogen. If there is more circulating estrogen in the body and you have estrogen-receptor positive breast cancer, it could pose a problem. More info in this article: I hope this info helps-
      Warmest regards,
      Marnie Clark

  15. Hi marnie, thank you for being there BC patients. May i please asked if its ok to drink turmeric tea and use it in cooking while undergoing herceptin treatment. Thank you for your reply.

  16. I am 35 with triple positive breast cancer, stage 1a. I just finished 1 of 6 treatments of TCHP chemo and will continue herceptin for 1 year. My chiropractor/naturopath recommended essiac supplements. My oncologist said it was fine to try but that she didn’t have info on effectiveness. Would you recommend essiac simultaneous to my chemo treatments? I’ve heard so many mixed messages on essiac. Thank you so much for your comprehensive food list!

    1. Rachael,
      I apologize for the lengthy delay in responding – for some reason I did not see your message come in. No doubt by now your chemo regimen has ended? If so, I can definitely recommend essiac tea to help keep you well, but there are so many other things too. Check out my page: Also: You might also like to subscribe to my free newsletters on how to get well and stay well. You can sign up from any page of my website. I hope this finds you well and I’m sorry for the long delay in responding.
      Warmest regards,
      Marnie Clark

  17. Thanks for sharing such vital information. My mother is diagnosed with her 2 positive. I cudnt understand which all food to avoid soya products n cow milk are not good for her? M in distress and feel helpless. Pls help.

    1. Urmi,
      Thanks for your message. Re the cow’s milk, it kind of depends on where in the world you are. If you’re in a part of the world where they don’t mess with the dairy cattle by giving them hormones and antibiotics, dairy products MIGHT be okay but only a very small amount. Whole soy products are generally not a problem, but those containing “soy protein isolate” are linked to a higher risk for breast cancer. Urmi, if you would like to sign up for my newsletters and information (all free) you can use the sign-up form on any page of my website. I’d be happy to help you and your mother as best I can.
      Warmest wishes,

  18. Hi,

    Nice to see such detailed Blog on HER2/neu. My Mother (59) was diagnosed with the HER2/neu positive breast cancer in 2011. Mastectomy was don for the right breast along with 6 cycles of chemo (without Herceptin), no radiation. Now, it has return back as metastatic cancer which doc say is Stage IV and have decided to go with Chemo along with Herceptin, which they say might be a life long medicine which she need to have for prolonged life. This looks like a long and tough battle for her as well as us.
    Doctors scare us a lot and do not comment on what diet should be given to her which may help her to fight with HER2/neu as well as recover fast from Chemo and side effects of Herceptin. It will be really great if you can help us out on what is good and what is not good for her at this time.

    1. Ankuz, thanks for your kind comments about my website. I’m sorry to hear about your mother, it does sound like she has a battle ahead. Please make her aware, though, that she can heal stage IV breast cancer, it can be done. Diet will be hugely helpful to her, make sure you visit my Diet and Cancer page: Also follow the guidelines on this page that you’ve commented on. See also my “must have” supplements page: You might also like to sign up for my free newsletters sharing the latest research and information on how best to heal from breast cancer using conventional and natural medicine. You can sign up from any page on my website – over on the far right-hand side of the page there’s a signup form. Blessings to you and your family during this difficult time.
      Warmest regards,

  19. Hi marine so glad found your page i have secondry breast cancer HER2 positive .left breast Masectomy but spread to right lung been on herceptin 3 and half years .thankyou so much for information on what to eat and not .the cancer hasn’t spread anywhere else and remains the same after last 2 scans .i have had paclitaxel for 18 weeks and changed my dietary intake and include some of foods you advise .i feel so much better in myself and have always thought it down to what you eat and lifestyle can’t thankyou enough .my name is Iris and from Liverpool uk .

    1. Hello Iris in Liverpool!
      Thanks for sharing that info with me. I’m glad to read that you are feeling better. There are some other pages from my website you might find useful: and this one on essential oils: Check them out, any questions, let me know!
      Warmest regards,
      Marnie Clark

  20. Hi Marnie,
    Can HER2 positive breast cancer consume Avocado, Kidney beans, black beans and black rice?
    Look forward to hearing from you:-)



    1. San,
      Thanks for your question. Yes indeed – avocados, kidney beans, black beans and black rice are all potent cancer-fighters and should be included in your diet.
      All the best

  21. Hi Marnie,

    I have just been diagnosed with HER 2 positive ER+/ PR+ Breast Cancer. I have done a lot of research on diet and have done the complete overhaul diet change. However I am looking for recipes for for the foods I can eat. I wasn’t sure if there were specific ways of cooking things that makes the ingredients more beneficial. For example I fried up some salmon the other day and then found out frying is not good for the type of cancer I have. Would that be the case with all foods? Any insight or suggestions for cooking books that might have the right recipes for my type of breast cancer would be greatly appreciated! Thank you for the extremely helpful website!


    1. Tina,
      I’ve just sent you some information via email. For the purposes of other people wanting to know my answer, I’m not aware of any cookbooks that have been written for HER2 positive people but cancer is cancer and responds well to particular phytochemicals. Be sure to follow the information on this page and my Diet and Cancer page and you’ll do well. Raw food is better than cooked because it contains healing enzymes and phytochemicals which can be wrecked in the cooking process. Be sure to visit my article for more information. Hope this helps!
      Warmest regards,

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