Cancer Active
Cancer Prevention Cancer Treatment Support Us Online Shop
Chris Woolmams / Catherine Woollams
Natural Aromatase Inhibitors

Aromatase Inhibitors – are there natural alternatives to the breast cancer drugs?

The use of Aromatase Inhibitors (AI’s) is now common practice with breast cancer patients who are Oestrogen Positive (ER+).. As breast cancer drugs, AI’s work by inhibiting enzymes in the body that are needed for the production of the female sex-hormone Oestrogen. Oestrogen is typically produced by the ovaries, but this declines as a source after menopause. What few women realise is that there are several other sources for oestrogen production – for example the liver, and fatty tissue under the skin. AI’s affect them all.

Before the advent of the AI drugs like Arimidex, Exemestane, and Letrozole (Femara), 20th Century women seemed exposed to the new threat of too much oestrogen. This of course is not true – for thousands of years, nature provided the answer.

New research evidence

Natural foodIf diets high in natural foods that inhibit the aromatase enzyme are eaten, breast cancers in postmenopausal women don´t get a chance to start, according to research from the University of Aromatase Inhibitors Munster in Germany. Scientists there have found that aromatase inhibitors are what keep normal cells from developing to the point where they can be classified as Grade 1 cancer.

All women have oestrogen receptor sites on the surfaces of their breast cells – alpha and beta sites. After puberty, these sites receive the oestrogen hormone and as a result the cells grow and the breast develop. It is only much later in life that an excess of oestrogen can continue to stimulate the rapid division of breast cells and create the problem that occurs in the majority of breast cancers.

In a study designed to determine the effectiveness of natural AI’s compared with common anti-oestrogen drugs, German scientists analysed 21 human breast cancer tissue samples and concluded that the transition from normal breast cells to grade 1tumours was characterised by the down-regulation of the beta sites, while the transition from grade 1 to grade 3 tumours involved a decrease in alpha expression.

Their research then tested the breast cancer drug tamoxifen which saw an increase in alpha expression and left ER beta unchanged. Next they tested AI drugs and found that beta expression was increased and thus the initiation of cancer was blocked. (Anticancer Research, June 2009)

Natural Alternatives

Unsurprisingly for those of us who have studied natural compounds in foods, nature equipped women to fight breast cancer all along. Importantly, our scientific knowledge is improving all the time.

Possibly the most potent natural compound is Indole 3 Carbinol, which acts in a number of ways, from denaturing aggressive oestrogen and its by products to rebalancing oestrogen receptor sites. I3C is almost ‘the wonder compound’ it has so many beneficial effects – from being a natural Tamoxifen, without the side effects to an inhibitor of dangerous dioxins in the body. Natural supplements are available; synthetic drugs are in preparation.

Phytoestrogens from all manner of plants can increase alpha and beta expression and effectively block the disruptive effects of excess of the aggressive human hormone. Abundant in green vegetables, fruits and particularly pulses like chick peas and beans, you can also find a particularly potent alpha and beta site balancer in red clover – the herb of Hippocrates – the active ingredient is genistein. Flavenoids are abundant natural sources of alpha and beta site regulation:

Quercetin is a main ingredient of the Plaskett therapy (Professor Plaskett ‘polished’ the Gerson Therapy in the mid 1990’s using the latest scientific research). It is widely available in onions and apples, however it denatures rapidly in the body and so it seems that the potency comes not so much from the quercitin itself but from its breakdown by-products. Science is playing catch-up tracking their effects, but apart from the usual antioxidant and anti-inflammatory benefits, and anti-bacterial/anti-viral factors, there is research indicating that they have AI benefits in breast cancer cells. Other sources include garlic, kale, brussel sprouts and cabbage. You can supplement.

Grapes1Resveratrol is another flavenoid covered on our web site – we have featured research on it from Harvard several times in Cancer Watch. It is the natural protective agent in the skins of red grapes and black and red berries. Amongst its many benefits, there is research on its breast cancer control via oestrogen receptors. But as we have told you before, please don’t think drinking a glass or two of red wine will have any effect, the doses would be way too low. Natural supplements are available – and drugs are on their way.

Just as we can tell you about the benefits of certain foods, so we can warn you of others! For example, some foods might be avoided if you are looking to reduce your oestrogen effect – for example grapefruit, which is a source of the flavenoid naringenin. Unfortunately, this flavenoid inhibits human cytochrome P450 isofrom, an enzyme involved in actually breaking down and metabolising sex hormones and preventing their excess accumulation in the body!

Finally there is chrysin, a flavonoid from the passion flower plant and a strong natural AI with clear research supporting its effects. Drugs have been prepared from this plant, but the natural compound also exists as a supplement  Another natural compound, piperine, enhances its action..

We cover many such natural compounds in detail in this web site, and in my book ‘The Rainbow Diet – and how it can help you beat cancer’.

Want the latest news on this?
Print This Page
  Search Website
Follow us on:
Follow us on Facebook Follow us on Twitter
Melatonin - self defence against cancer

CANCERactive Website Appeal
raised of £25,000 target

Click Here to donate

Select a donation amount:
Enter a donation amount:

Gift Aid:
So that CANCERactive can claim back 25p for every £1 donated, I confirm that I am a UK tax payer, who has paid over enough tax for you to reclaim this amount

Sign up for icon


Our icon magazine is available free in over 500 UK hospitals, cancer centres and libraries. Full of great articles and the very latest cancer information, you can have it sent to your own home.

Buy online

The CANCERactive Patient Group (CAPG) – Run by Patients, for Patients

  • Tell your Story
  • Start a Blog
  • Start a Diary Blog
  • Start a Discussion
  • Ask a Question

Search Drugs


Quick search for YOUR DRUG here  

Search Drugs


Quick search for a COMPLEMENTARY THERAPY here 

Search Complementary Therapies



Search Alternative Therapies

Important Notice

At CANCERactive we provide information that is already in the public domain.  It is not our intention to provide advice. It is up to the reader to decide if any of the matters to which any article refers might be suitable for them.


Follow CHRIS WOOLLAMS, the UK's number 1 cancer researcher, on his free e-news and keep right up to date with the very latest cancer information and research

 click here

  click here

click here


CANCERactive information and publications (books, magazine and leaflets)

CANCERactive compiled books

Heal Your Gut Heal Your Body

A real paradigm shift - this book will help you really understand exactly what to do to be in great health.

Click here to find out more.

The Brand new 4th edition of Everything You Need to Know to Help You Beat Cancer

"This book is head and shoulders above the rest". Geoffrey Boycott

Click here to find out more.

The Rainbow Diet - and how it can help you beat cancer

"At last the definitive book on a diet to fight cancer". Mrs BS Devon.

 Click here to find out more...

Brand new 3rd edition of Oestrogen The Killer in our Midst

"Learn how to take control of your oestrogen levels"

 Click here to find out more...

CANCERactive magazine (free in hospitals and complementary cancer centres)


Free downloadable prevention leaflets


Buy online

Donate to Us

We can only help people like you - if people like you help us!

Buy online

Fund Raising


Interested? Click here for more information

Click here to see all our fundraising events.

Click here and see what events are taking place and perhaps sponsor one of our supporters. 

Click here for other ways to raise money for CANCERactive.

Or if you want more information about our other fun activities, the Peru trek, our sky diving etc. click the button below.

Click here for our Just Giving page and see what our supporters are doing for us.

Click here for our Virgin Money Giving page.

Buy online

Visit a Catherine Corner

Catherine Wollams

Buy online

Need a Support Group?  

Find a cancer support group near you, now.
Buy online

So what is the truth behind mammograms, drug clinical trials, the PSA test and prostate surgery, and the stories you read in the press?Go to Junk Science to read the unbiased truth. Click Here.


Do you have a problem with our factual content?

If you have research which conflicts with ours, just address it to 'The Medical Board'. Ever since we started this site we have had an 'open-mind' policy and have expert oncology doctors and professors who will address your concerns.

© Copyright 2017 CANCERactive. All Rights Reserved. This content may be copied in full, with copyright, contact, creation and information intact, without specific permission, when used only in a not-for-profit format and provided, where used to publish on a website, that website provides a link to If any other use is desired, permission in writing from CANCERactive is required.
All content and images © Copyright 2017 - Website design and maintenance by a Web design and Search engine marketing company