June 3rd, 2011
03:51 PM ET

How much is too much phytoestrogen?

Every weekday, a CNNHealth expert doctor answers a viewer question. On Friday, it's Dr. Melina Jampolis, a physician nutrition specialist.

Asked by Keyana of Spokane, Washington:

I have two questions. What is considered to be a high/harmful amount of phytoestrogen in a woman's diet per day? And should a woman who has had cancer not take estrogen replacements or eat a diet high in phytoestrogens?

Expert answer:

Hi, Keyana. These are interesting questions. I'm going to assume that you are talking about breast cancer since the association of phytoestrogen consumption and breast cancer risk is the most concerning to many women.

Phytoestrogens are plant-based compounds that act like the hormone estrogen. There are two basic types of phytoestrogens: isoflavones and lignans.

Soy products are the most common source of isoflavones, and the controversy surrounding cancer and phytoestrogens are related to soy products. To provide you with the best possible response to your question, I turned to noted cancer nutrition expert Rachel Beller, who addresses this question on a regular basis at the Beller Nutritional Institute in Los Angeles.

Beller explained that while phytoestrogens are similar to human estrogens, their effect on human estrogen levels has not been well-researched because plant estrogens are 1,000 times weaker than the estrogen produced in our bodies.

Many studies suggest that soy isoflavones' estrogen-like effects are probably too weak to have any significant consequence on breast tissue in healthy women - that includes breast cancer survivors.

Regarding the association with breast cancer, Beller points to a 2011 study published in Cancer Epidemiology, Biomarkers & Prevention that found soy to be safe and favorable, even for breast cancer survivors, when eaten in its natural, unprocessed state - for example, tofu, tempeh, edamame, miso soup.

In fact, experts agree that fermented soy (miso, tempeh) is good for you. The fermentation process alters the chemical makeup of soy, which reduces the level of isoflavones by as much as 300%.

Therefore fermented soy foods have three times less of the chemical in question.

While this study does not conclusively establish the safety of soy, phytoestrogens aside, soy is not only an excellent source of heart healthy plant-based protein, which is encouraged in the latest dietary guidelines for Americans, it also contains dozens of nutrients that also appear to help fight cancer development.

These nutrients can protect cells from becoming damaged, encourage faulty cells to die instead of reproducing, regulate cell growth and even improve cell communication. These are all things that help strengthen your body against cancer and heart disease.

A study has also shown that consumption of soy early in life may help protect against breast cancer later in life, even if it may be more questionable for post-menopausal women.

What's also noteworthy is that Asians have been eating soy foods in large amounts for centuries, and their traditional soy-rich diets are associated with lower risks of breast and prostate cancer than Western diets.

Beller goes on to say that the "bad rap" that soy's been getting is due to the fact that when we hear something's "good for you," we process it to the max, extract the good stuff and concentrate it, which basically makes it lose its original identity.

Skip the processed soy foods and supplements, especially if you have a history of breast cancer.

The bottom line: If you have no history of breast cancer, there is no known high or harmful amount of phytoestrogens, and foods such as unprocessed soy are an important part of a healthy diet.

If you have a history of breast cancer, as with nutrition in general, you should not focus on a single food or nutrient. The key is moderation.

The phytoestrogens consumed by eating moderate amounts of relatively whole and unrefined forms of soy foods (two to three times a week) can be considered part of a healthy, complete diet.

Regarding estrogen replacement therapy, according to the National Cancer Institute, "Studies of hormone use to treat menopausal symptoms in breast cancer survivors have produced conflicting results," so I suggest speaking with your physician to determine the best approach for you.

Follow Dr. Jampolis on Twitter

soundoff (924 Responses)
  1. tadalafil dosage

    tadalafil uses tadalafil price at walmart tadalafil brands

    June 3, 2021 at 19:35 | Report abuse | Reply
  2. orange truck shop


    June 3, 2021 at 20:26 | Report abuse | Reply
  3. truck repair close to me

    This website truly has all the information and facts I needed concerning this subject and didnít know who to ask.


    June 3, 2021 at 21:30 | Report abuse | Reply
  4. rv parts store close to me

    Hi, I do believe this is a great website. I stumbledupon it 😉 I may return once again since i have bookmarked it. Money and freedom is the greatest way to change, may you be rich and continue to guide other people.


    June 3, 2021 at 21:51 | Report abuse | Reply
  5. EncoxDev

    canada online pharmacy legitimate online pharmacy meds online schools for pharmacy tech

    June 3, 2021 at 21:57 | Report abuse | Reply
  6. dump truck paint schemes

    I really like it when people get together and share views. Great website, stick with it!


    June 3, 2021 at 22:26 | Report abuse | Reply
  7. Mercedes Sprinter Service Centers

    I used to be able to find good info from your blog posts.


    June 3, 2021 at 22:38 | Report abuse | Reply
  8. trailer body repair near me

    Nice post. I learn something totally new and challenging on sites I stumbleupon everyday. It will always be useful to read through content from other authors and practice a little something from their sites.


    June 4, 2021 at 07:32 | Report abuse | Reply
  9. Sprinter Calliper Repair


    June 4, 2021 at 07:42 | Report abuse | Reply
  10. EncoxAni

    commonly abused prescription drugs reputable online pharmacy ed pills online

    June 4, 2021 at 08:16 | Report abuse | Reply
  11. Van Wheelchair Lift Repair


    June 4, 2021 at 09:31 | Report abuse | Reply
  12. Zisseloh

    cialis tinnitus does cialis help bph cialis wikipedia

    June 4, 2021 at 10:44 | Report abuse | Reply
  13. Zisseloh

    when do you take cialis cialis cost when to take cialis

    June 4, 2021 at 11:01 | Report abuse | Reply
  14. dj rv center


    June 4, 2021 at 13:39 | Report abuse | Reply
  15. toy hauler upgrades


    June 4, 2021 at 19:17 | Report abuse | Reply
  16. yoga near me


    June 4, 2021 at 19:20 | Report abuse | Reply
  17. Mercedes Sprinter Repair Near Mee

    After I originally commented I seem to have clicked on the -Notify me when new comments are added- checkbox and from now on whenever a comment is added I get four emails with the exact same comment. Perhaps there is an easy method you can remove me from that service? Thank you!


    June 4, 2021 at 19:50 | Report abuse | Reply
  18. Repair Fuel Pump Mercedes Sprinter Dodge 3500 2010


    June 4, 2021 at 20:08 | Report abuse | Reply
  19. EncoxDev

    cipa canadian online pharmacies fake canadian pharmacies trustworthy canadian pharmacies

    June 4, 2021 at 20:46 | Report abuse | Reply
  20. rv awning replacement near me


    June 4, 2021 at 21:30 | Report abuse | Reply
  21. EncoxAni

    canadian healthcare online pharmacy reviews london drugs computers canada oxford pharmacy store

    June 4, 2021 at 22:24 | Report abuse | Reply
  22. EncoxGtv

    america pharmacy online canadian pharmacy ship to us pharmacy discount coupons

    June 5, 2021 at 03:32 | Report abuse | Reply
  23. buy cialis pills

    sublingual tadalafil cialis 20mg purchase peptides tadalafil

    June 5, 2021 at 07:23 | Report abuse | Reply
  24. Dry Van Floor Repair


    June 5, 2021 at 10:15 | Report abuse | Reply
  25. rv ac repair near me


    June 5, 2021 at 10:47 | Report abuse | Reply
  26. landscaping near me

    I would like to thank you for the efforts you have put in writing this website. I am hoping to see the same high-grade content by you later on as well. In truth, your creative writing abilities has encouraged me to get my very own blog now 😉


    June 5, 2021 at 11:21 | Report abuse | Reply
  27. Social Media Marketing Consultants Near Me


    June 5, 2021 at 12:03 | Report abuse | Reply
  28. Dodge Sprinter Auto Repair

    Hi there! This article could not be written much better! Reading through this post reminds me of my previous roommate! He continually kept preaching about this. I am going to forward this information to him. Fairly certain he'll have a great read. I appreciate you for sharing!


    June 5, 2021 at 13:47 | Report abuse | Reply
  29. motor home repair parts


    June 5, 2021 at 18:02 | Report abuse | Reply
  30. doctors for hydroxychloroquine

    drug chloroquine side effects for plaquenil cloriquine

    June 5, 2021 at 20:58 | Report abuse | Reply
  31. https://www.songmanhits.com

    Best view i have ever seen !


    June 6, 2021 at 00:22 | Report abuse | Reply
  32. tadalafil dosage

    tadalafil and dapoxetine cialis without prescription vidalista 40 side effects

    June 6, 2021 at 03:01 | Report abuse | Reply
  33. Los Angeles Sprinter Repair


    June 6, 2021 at 08:33 | Report abuse | Reply
  34. Mercedes Sprinter Authorized Repair Center


    June 6, 2021 at 09:31 | Report abuse | Reply
  35. marco's pizza near me


    June 6, 2021 at 15:52 | Report abuse | Reply
  36. aralen

    dangers of hydroxychloroquine chloroquine phosphate generic name hydroxchloroquine

    June 6, 2021 at 22:49 | Report abuse | Reply
  37. MileSwa

    cialis price per pill lowest price on cialis 200 mg cialis generic canada pharmacy

    June 7, 2021 at 04:22 | Report abuse | Reply
  38. CrulkAsd

    mastercard generic cialis truth behind generic cialis cialis pre

    June 7, 2021 at 16:37 | Report abuse | Reply
  39. https://dungcuthethaongoaitroitb.blogspot.com/2021/06/ban-cau-truot-ngoai-troi-cho-be-tai.html

    I'm more than happy to find this web site. I need to to thank you
    for your time for this wonderful read!! I definitely enjoyed every little bit of it
    and i also have you book marked to check out new stuff
    on your web site.

    June 7, 2021 at 19:46 | Report abuse | Reply
  40. EncoxHtf

    cheapest cialis canada buying cialis cialis not working for me

    June 7, 2021 at 21:24 | Report abuse | Reply
  41. rv plumbing leak


    June 8, 2021 at 02:10 | Report abuse | Reply
  42. blind repair orange county


    June 8, 2021 at 03:52 | Report abuse | Reply
  43. rv renovations near me

    Having read this I thought it was really enlightening. I appreciate you taking the time and energy to put this informative article together. I once again find myself spending way too much time both reading and leaving comments. But so what, it was still worth it!


    June 8, 2021 at 04:30 | Report abuse | Reply
  44. RV Plumbing Riverside

    There's certainly a great deal to know about this topic. I love all of the points you have made.


    June 8, 2021 at 04:40 | Report abuse | Reply
  45. ZisseVed

    cost of cialis 5mg online buy cialis generic viagra cialis

    June 8, 2021 at 07:36 | Report abuse | Reply
  46. EncoxGtv

    online pharmacy australia pharmacy rx solutions canadian cipa pharmacies

    June 8, 2021 at 10:12 | Report abuse | Reply
  47. CrulkAsd

    viagra cheap generic cialis pictures of penis on cialis over night cialis

    June 8, 2021 at 16:17 | Report abuse | Reply
  48. recreational vehicle repair service

    Iím impressed, I must say. Seldom do I encounter a blog thatís both equally educative and interesting, and let me tell you, you've hit the nail on the head. The issue is something which not enough folks are speaking intelligently about. I'm very happy that I found this during my search for something concerning this.


    June 9, 2021 at 02:22 | Report abuse | Reply
  49. RV Mattresses Riverside

    May I simply just say what a relief to discover an individual who actually knows what they are discussing on the net. You actually understand how to bring a problem to light and make it important. A lot more people have to look at this and understand this side of your story. I was surprised you are not more popular since you definitely have the gift.


    June 9, 2021 at 04:29 | Report abuse | Reply
  50. rv camping in orange county ca


    June 9, 2021 at 07:11 | Report abuse | Reply
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

Leave a Reply to New Forklift Tires California


CNN welcomes a lively and courteous discussion as long as you follow the Rules of Conduct set forth in our Terms of Service. Comments are not pre-screened before they post. You agree that anything you post may be used, along with your name and profile picture, in accordance with our Privacy Policy and the license you have granted pursuant to our Terms of Service.

About this blog

Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.