Can Nutrition Help Prevent Cancer?
An Interview with Jeanne Wallace


BHP:  Jeanne, tell us about your background and qualifications.

Jeanne:  I have been working in the field of nutrition since 1989 and am a registered member of the National Association of Nutrition Professionals (NANP #20022). I hold both a Master's and PhD degrees in human nutrition from American State University in Honolulu, HI (an external degree program).

In addition, I have completed 750 hours of classroom instruction at the Institute for Educational Therapy (now Bauman College), a California-state licensed nutrition consultant training program considered one of the best in the country. By comparison, most U.S. medical schools require physicians to complete only 2-4 hours instruction in nutrition.

I have served as a member on editorial boards for several peer-reviewed medical journals, including Integrative Cancer Therapies and The International Journal of Integrative Medicine.


BHP: Can diet be used to help prevent breast disease? How?

—Yes, diet offers many protective effects against breast cancer.

[1] Dietary antioxidants help reduce DNA damage and contribute to gene stability. The accumulation of DNA damage is implicated as a contributing factor in cancer development. Fruits, vegetables, green tea and kitchen spices are rich in protective dietary antioxidants that can help slow the accumulation of this damage.

In fact, hundreds of studies have linked high intake of these fruits and vegetables with reduced risk of breast (and other types of) cancer. A good motto is “Eat Eight”—8 or more 1/2 cup servings of fruits and vegetables each day. Foods richest in cancer fighting nutrients are fruits and vegetables that are organically-raised, locally grown, fresh and in season. Select those with the deepest colors (e.g., a pale tomato has much less lycopene than a vine ripened, deep red organic one).

[2] Diet influences detoxification. Detoxification enzymes in the liver are responsible for clearing toxins we are exposed to on a daily basis. Constituents found in healthy foods (e.g., chlorophyll in leafy green vegetables, garlic, broccoli, lemons and citrus and many other foods) can optimize the enzymes that remove carcinogens or prevent their activation.

[3] A healthy diet reduces inflammation. Studies since the 1980’s have linked the use of anti-inflammatory medications with a reduced risk of many cancers, including breast cancer. Systemic inflammation (which is generally without observable symptoms) is a significant factor in developing breast cancer, and also in the progression of established cancers.

A diet that prevents a chronic inflammatory state can help prevent breast cancer, as well as be useful for those with diagnosed breast cancer. To help control inflammation, avoid refined processed carbohydrates and sweets, eat foods rich in omega-3 fats (cold-water fish, flaxseeds, walnuts, grass-fed meat dairy and poultry, high-omega-3 eggs). Limit excessive intake of omega-6 fats from vegetable oils (except olive oil), commercially raised meat dairy and poultry.

[4] A healthy diet optimizes immune function. While the immune system has limited capacity to address established cancers, it is essential for detecting and eliminating early precancerous cells and controlling micrometastases.

[5] Diet appears to have a significant impact on angiogenesis (the recruitment of a network of new blood vessels to nourish a tiny cluster of cancer cells and allow its progression). Refined carbohydrates, high cholesterol and excessive calorie intake have been shown to foster this process. And many foods and nutrients may inhibit it, including berries, soy foods, green tea, kitchen spices (especially mint, a source of apigenin), garlic, selenium and vitamin D.

BHP: Can diet influence estrogen metabolism and estrogen symptoms?

Absolutely. In fact, there are several pathways of estrogen metabolism and modulation that are not addressed by common pharmaceutical approaches but which are amenable to diet or nutritional influence.

[1] Some foods may contain appreciable amounts of estrogen: commercially raised dairy products and meats (in which the cows have been medicated with Zeranol or other estrogenic drugs to stimulate growth or milk production). Some feel that high levels of estrogen in commercial dairy and meat may explain earlier puberty, where we are seeing very young girls with breast development and menarache.

Estrogen in dairy products may explain why some studies have linked high dairy fat intake with increased breast cancer risk (whereas a large Finnish study, where cows are raised more traditionally, actually found dairy consumption protective against breast cancer risk). Avoiding commercially raised dairy and selecting organic, hormone-free, grass-fed meat, dairy and poultry may help reduce unwanted exposure to dietary estrogens.

[2] There are also xenoestrogens, compounds that act as very potent estrogen mimics (they can be 1,000 times stronger than our own estrogen), and appear to be implicated as a contributing factor in breast cancer and other disorders of hormone disruption (e.g., endometriosis, cervical cancer, infertility).

These are found in soft plastics (pthalates), bisphenol-A (found in plastic wraps and the plastics that line many canned goods), and in many herbicides and pesticides.

Choose organic foods. Avoid heating foods in plastic containers (choose ceramic or glass). Avoid storing foods with oils/fats in plastic wrap (choose cellulose bags, or wax or parchment paper with an outer layer of tin foil to seal out air).

Invariably, women across the globe have been exposed to xenoestrogens, which are very difficult for the body to eliminate.

Lindsay Berkson, in her excellent book Hormone Deception, discusses the effective use of low-heat saunas (e.g., sweating) to help remove xenoestrogens, and some preliminary research suggests the curcumin, from the curry spice turmeric, may also be beneficial here.

[3] In stark contrast to xenoestrogens, some foods offer phytoestrogens, which act as Selective Estrogen Receptor Modulators (SERMS). Phytoestrogens have been estimated to be 500-1,000 times weaker than human estrogen. By docking on estrogen receptors in the body, phytoestrogens may prevent activation of these receptors by our own estrogen and xenoestrogens, reducing net estrogenic effect.

Flaxseed and soy are widely known for their phytoestrogens, but there are many others, including whole grains and legumes, nuts and seeds, some fruits and vegetables, and many kitchen spices.

[4] Some foods increase Sex Hormone Binding Globulin (SHBG), a protein that binds estrogen. When SHBG is low, levels of free estrogen are higher, a concern for women with ER+ breast cancer and other conditions of estrogen dominance. Flax seeds have been shown to elevate SHBG, thereby reducing the amount of free estrogen which can act on breast tissue.

[5] We can also shift the way the liver metabolizes estrogen. The liver transforms estrogen into daughter compounds, which have differing effects on breast tissue. 2-OH estrogens are favorable, offering protective effects, whereas 16-OH estrogens are unfavorable, and a preponderance of 16-OH estrogen is linked with increased risk of breast cancer.

Brassica family vegetables shift the balance toward favorable 2-OH estrogens. This family includes: broccoli (and broccoli sprouts), cauliflower, cabbage (red, white, napa cabbage and bok choy), brussel sprouts, arugula, collards and kale, daikon radish, kohlrabi, rutabaga, turnip and watercress. Flaxseeds, soy foods and fish oil have also been shown to help shift the balance toward favorable estrogen metabolites.

[6] Dietary factors can also influence the clearance of estrogen. The liver employs glucaric acid (or glucarate) to break down and remove estrogen from the body. Foods or supplements with glucarate (cherries or calcium-D-glucarate) can assit in optimum clearance of estrogen. Women with sluggish liver function often have excess circulating estrogens, because the liver has the job of removing estrogen.

A high fat diet can hinder optimal liver function, and this may also help explain why some studies have shown a relationship between high fat diets and estrogen-excess diseases, like breast cancer.

Avoidance of excess alcohol intake is important, since the liver enzymes that break down alcohol are also used to clear estrogen. Excess alcohol intake is associated with much higher estrogen levels.

Intake of caffeine is also associated with higher estrogen levels (I suggest limiting intake to only the amount present in your green tea, about 90mg/day or less).

[7] After estrogen is cleared by the liver, it is excreted into the intestinal tract. The intestines are home billions of healthy bacteria, like acidophilus and bifidus species. When a state of dysbiosis exists (a predominance of unfavorable bacteria), the unwanted bacteria employ an enzyme called beta-glucaronidase, which can re-assemble the estrogen metabolites, recreating active estrogens.

Also of note, the estrogen metabolites must bind to fiber, or they may be re-absorbed. A diet low in fiber, and/or a history of chronic constipation are associated with excess estrogen. To improve the situation: eat foods rich in soluble fibers (from vegetables, fruits, legumes and whole grains, especially oatbran).

In addition, choose foods that offer healthy bacteria include: miso, organic yogurt with live cultures, fermented vegetables like kim chee or sauerkraut, and fermented beverages like rejuvelac, keffir or amazake. Some organic brands offer cottage cheese and milk with live acidophilus cultures.

[8] The trace mineral boron has been shown to elevate estrogen levels, and should probably be avoided by women with ER+ breast cancer or other disorders of estrogen dominance (fibroids, endometriosis, cervical cancer, etc). These means selecting a multiple vitamin without boron, and if you have cancer, also without copper or iron.

9] Lifestyle changes can also influence estrogen. The body aims to maintain a balance between estrogen and progesterone. The synthesis of the stress hormone cortisol derives from progesterone. Under stress, levels of progesterone may be depleted to make cortisol, leaving estrogen unopposed. So stress reduction techniques (exercise, support groups, massage, bubble baths, meditation, imagery, etc) can help reestablish the balance between estrogen and progesterone.

[10] Our sleep habits can also influence estrogen levels. Melatonin—the hormone produced by our brain’s pineal gland when we sleep in complete darkness— helps decrease excessive estrogen production. So avoiding ambient light exposure at night while sleeping (and avoiding nightshift work) can also help us prevent estrogen excess.

Addressing each of these areas—to get a fully synergistic approach—represents a wonderful complement to hormone therapies for women with ER+ breast cancer. These approaches can also be used to address symptoms of estrogen dominance and promote breast health.

BHP:  If there is a general diet that works for everyone, how does one know what will work for them?

—There are so many diet dictates. Some common controversies include:
[1] Eat all raw foods (Gerson or Hippocrates Institute approach) vs. Avoid raw foods, eat only cooked foods (Macrobiotic plan)
[2] Eat meat & dairy (Caveman Diet) vs. Vegetarian or vegan diet
[3] Complex carbs are good vs. Limit carbs (Zone or Atkins approach)

No one approach is right for everyone. Instead of viewing these different diets as right vs wrong or subscribing to any particular nutrition dogma, I like to ask, "What health goal does this diet approach accomplish and is that goal well suited to this client’s needs? How does eating this way support health? What pearls of wisdom does this approach provide? For whom is this way of eating best suited and for whom might it be detrimental?

I evaluate these approaches, merge the best suggestions from each into a plan that will best support each clients health. To individually tailor the diet, I consider many factors, including:

Do this client need a building, balancing or cleansing diet? How can we shift the ratio of protein-to-carbohydrate-to-fat to offer this effect?

Does she need foods that are cooling vs warming?
What season are we in? Summer (more raw foods): winter (more cooked foods).

What diet approach is needed to help balance blood sugar levels?

Are there specific foods with research suggesting cancer-fighting effects against this client’s cancer that should be emphasized in her diet?

Does the client have food intolerances or allergies that need to be addressed?

Does her cultural inheritance (and/or blood type) suggest a particular diet? If your ancestors ate specific foods for thousands of years, your genetic inheritance may dictate a specific diet or avoidance of certain foods.

Does prior malnutrition necessitate particular dietary interventions?

Sometimes a bit of trial and error is needed. When you’ve hit on the right diet for you, your energy and vitality increase, you feel clear headed, grounded and balanced. You sense that you are thriving as opposed to merely surviving. Your blood sugar levels improve. Your inflammation marker (C-reactive protein) is low. Nutritional markers on your blood work (such as albumin) improve. Your weight moves toward ideal and stabilizes. You experience a sense of well-being. If these benefits diminsh, you adapt and make changes in the diet again to find a new place of balance.


BHP:  How necessary are supplements? Don’t we get enough nutrients in our food? There are so many products out there, how do you know what is good?

—I believe supplements are necessary. However, supplements are never a substitute for a healthy diet. Sometimes people make the mistake of thinking a multiple vitamin will cover all their needs, and they continue a poor diet with a false sense of security. There are thousands of cancer-”phyting” phytonutrients present in foods which are not supplied in vitamin pills. A healthy diet comes first, it provides the foundation for health.

Nonetheless, studies have shown the majority of us do not obtain the recommended intake of all the essential vitamins/minerals from our diets. Add to that, commercial agricultural practices that have depleted many important nutrients from our soil and food.

Additionally, the RDA/RDI represents merely the bare minimum amount of a nutrient required to prevent a state of deficiency. When you are facing disease and cancer treatments, your requirements increase! Some nutrients are very difficult to obtain in meaningful amounts from diet alone, and a good quality multiple can really be helpful.

Because the supplement industry is self-monitored (not FDA regulated), many products do not contain what is listed on the label, or may contain contaminants.

When selecting dietary supplements, seek the guidance of an experienced nutrition professional who can help you find formulas that are tested by an indepenent third-party lab, and which provide an assay demonstrating their purity and potency. Avoid products that do not list the ingredients, their amounts and their sources (e.g., proprietary formulas). Read the label and avoid products loaded with excipients, fillers, binders, artificial colors, etc. Beware of methyl parabens added to some products: they are xenoestrogens.

In addition, the assistance of a nutrition professional is essential because there are so many details in selecting the best supplements for your unique individual needs. For example:

  • Is the source of the nutrient natural vs synthetic (especially important
    with beta carotene in light of the CARET study that showed potential
    risk of synthetic beta carotene supplements)?

  • Is the nutrient provided in its active form or precursor (e.g., pyridoxine
    HCL vs pyridoxal-5-phosphate, the active form of vitamin B6)?

  • Is it in a form that is absorbable (e.g., calcium citrate vs carbonate)?

  • Is it a complete or isolated compound (e.g., alpha tocopherol is only one of 8 compounds that make up vitamin E in nature; beta carotene is only one of several hundred carotenoids). Taking one can imbalance
    the others (e.g., alpha tocopherol supplements deplete gamma
    tocopherol, the most abundant vitamin E compound in the body).

  • Does this product supply the form used in studies of that nutrient (or is it another form not as well studied)?

  • Should the product be taken with food or on an empty stomach?

  • Which products should be taken together vs which need to be kept apart?

  • How long should you take the product: a week, a month, a year?

  • Are there potential interactions with the supplement and your
    medications or treatments?

My website offers an article on selecting high quality supplement that may interest some readers.

BHP: During cancer treatment, can women use supplements including antioxidants or does that make the treatment ineffective?

—Again, here, the guidance of a nutrition professional who specializes in nutritional oncology is essential. There are two separate issues here:

First, can supplements be taken with chemotherapy?

Second, can antioxidant supplements be taken during radiation or chemotherapy?

Let’s address these separately.

[1] Yes, some supplements can be taken durng chemotherapy. And there are published studies showing that several supplements may actually increase the efficacy of chemotherapy (or radiation) while mitigating side effects or toxicity.

Some well-researched supplements in this arena include: PSK (from the coriolus mushroom) and other mushroom extracts, melatonin, fish oil, selenium, glutamine, green tea and theanine (a compound found in green tea). Emphasizing supplements that have published research demonstrating their beneficial effects when combined with cancer treatments is a smart strategy.

A primary issue with taking supplements during chemotherapy is the risk of drug-nutrient interactions. For example, the herb St. John’s wort has been shown to interact negatively with several chemotherapy drugs.

Yet many herbal supplements have not yet been evaluated for interactions with cancer drugs. One way to screen for potential interactions is to consider the hepatic (liver) metabolism of the drug in question and that of the nutrient or herb.

For example, drugs are metabolized in the liver by cytochrome p450 enzymes (each of which is identified by number-letter-number, such as 1A1, 1A2, 2B6, 2C9, etc.). Many chemotherapy drugs are processed via the 3A4 pathway. This includes adriamycin (doxorubicin), cytoxan (cyclophosphamide), navelbine, taxol and taxotere.

Tamoxifen, arimidex and aromasin also use cyp450-3A4. Herbs that upregulate 3A4 may cause the liver to speed the clearance of these chemotherapy drugs, removing them before they complete their job. Conversely, herbs that inhibit 3A4 may lead to a buildup of the drug, increasing its toxicity.

Many common herbs act on 3A4, including curcumin, cat’s claw, echinacea, hops, kava, licorice, bioflavonoids, milk thistle, resveratrol, and quercetin. Grapefruit juice potently inhibits this pathway. Green tea impacts this pathway, but not at levels that are clinically significant.

These herbs have not yet been definitively shown to interfere with these chemotherapy drugs, and research may later show they are not a concern. But looking at the pharmacokinetics of the herbs suggests there is a potential for interaction, and until proven safe they should not be taken concurrently with these chemotherapy drugs.

If you are taking supplements during your chemotherapy, discuss these with your doctor, and find a pharmacist or oncology nutritionist who can assist your oncologist in evaluating for potential interactions.

[2] Now onto the topic of antioxidants. This issue of antioxidants during cancer therapy is very complex! We could have an entire interview just on this topic, and only scratch the surface. I don’t advise my clients to take nor to avoid antioxidant supplements. Rather, I provide them with up-to-date information about the published research in this area—and its strengths and weaknesses—so that they can make an informed choice about which they feel confident.

The idea that antioxidants will interfere with chemotherapy comes from the hypothesis that:

[a] because chemotherapy drugs are known to cause an increase in the body's levels of oxidation (i.e., free radicals) and

[b] because antioxidants neutralize free radicals, then

[c] it is possible that antioxidant supplements might interfere with the treatment?

Very little published scientific evidence supports this claimand a growing body of evidence has accumulated which suggests the opposite, that dietary antioxidants may actually improve the efficacy of chemotherapy treatments.

But the type of large-scale, double-blind, placebo-controlled, randomized trials that would definitively answer this question have not yet been done.

Several small human studies have examined the effects of antioxidant supplements in cancer patients taking chemotherapy. Knud Lockwood et al [1994, 1995] examined the effects of high-dose coQ10 (300-400mg/day) plus a potent multiple antioxidant supplement in women with metastasized breast cancer. These women have experienced improved treatment response (two women achieved a complete regression of all metastases) and none of the women have died during the 5- to 7-year study period.

Jaakkola et al [1992] examined the effect of antioxidant supplements in lung cancer patients undergoing chemotherapy plus radiation, and reported prolonged 5-year survival rates. Dr. Jeanne Drisko and colleagues at the University of Kansas Medical Center are currently studying high-dose vitamin C and antioxidants in women with ovarian cancer. Preliminary case reports from this group have been published [Drisko et al., 2003] and show improved efficacy of treatment and prolonged survival.

Several published review articles have summarized the scientific literature on antioxidants and cancer treatment [Moss 2006; Drisko et al., 2003; Block 2001; Conklin 2000; Simone et al., 1999; Prasad et al., 1999; Lamson & Brignall 2000, 1999; Weijl et al, 1997]. These 9 review articles suggest that antioxidants—with very few exceptions—improve the efficacy of chemotherapy while reducing its toxicity and side effects.

There are at least a dozen factors to consider, but given time constraints, let’s address just 3 of these:

[1] Antioxidant nutrients are tissue specific: in other words, many antioxidants have an affinity for certain organs or tissues and are found in these organs in high concentrations but in other locations in much smaller amounts, if at all.

Antioxidants that accumulate in the heart or brain, for example, may help to reduce the cardiotoxicity and neurotoxicity of some chemotherapy drugs for breast cancer. For example, coQ10 is present in high concentrations in the heart and brain, but very low amount in breast tissue.

The ability of coQ10 to reduce the cardiotoxicity of Adriamycin may be due to the accumulation of this antioxidant in the heart, without interfering with the cytotoxic (cancer killing) effects of the drug in the breast, ovary or other tumor locations.

[2] There many different types of free radicals: superoxide, hydroxyl radicals, hydrogen peroxide, to name a few. No single antioxidant protects against all types of free radicals: each antioxidant is specific for different types of free radicals. This means the blanket statement “antioxidants will interfere with chemotherapy” is overly simplistic. Rather, we must determine which types of free radicals are involved in the tumor-killing mechanism of each chemotherapy drug.

This would let us identify which antioxidants could potentially interfere with a specific chemotherapy agent, and which would be unlikely to interfere. A compelling study examined the relationship between free radicals and antioxidant supplements in cancer cells treated with Adriamycin (doxorubicin) [Cervantes et al., 1988]. In this study, Adriamycin toxicity could be inhibited by antioxidants that neutralize hydroxyl radicals (such as glutathione, N-acetyl-cysteine, lipoic acid), and these specific antioxidants moderately reduced the efficacy of the chemotherapy.

On the other hand, antioxidants that scavenge superoxide radicals or hydrogen peroxide (e.g., vitamin C) did not reduce the efficacy of the chemotherapy.

[3] Antioxidant nutrients have several other functions in the body, and their effects in cancer patients taking chemotherapy may derive from these actions.

For example, vitamins A, C, E and D have been shown to help regulate apoptosis (programmed cell death). New research demonstrates one mechanism of action for many chemotherapy agents is via damage to the tumor cell which then triggers apoptosis.

Vitamins may enhance chemotherapy via their ability to promote apoptosis. And some authors have suggested that withholding these nutrients may reduce the efficacy of chemotherapy by interfering with successful apoptosis.

One important exception: a small group of antioxidants which are not found in food, the endogenous antioxidants have a few studies showing benefit and a few suggesting the potential for inhibiting the efficacy of chemotherapy. This group includes glutathione, N-acetyl-cysteine, lipoic acid, superoxide dismutase and catalase. Until more is known about this special class of antioxidants, they should likely be avoided.

Finally, I’d like to offer an important observation here. While oncologists often warn cancer patients to avoid taking antioxidant supplements, the majority of our antioxdiant intake derives from the diet. The tested ORAC (oxygen radical absorbing capacity) of one 400iu pill of vitamin E is approximately 125 units, but foods like raspberries, cinnamon, pomegranate, tumeric, oregano, dark chocolate, green tea, strawberries, spinach, and kale all offer over 1,000 ORAC per serving. Blueberries have over 3,000 ORAC. A healthy diet offers an abundance of antioxidants, and we are not worried that these will interfere with cancer treatment.

BHP:  Often after breast cancer treatment, women feel tired of being on a restricted diet and just want to go back to “normal.” How important is diet after cancer treatment?

—I think it’s really important after cancer treatment to have a chance for life to “go back to normal.” To reclaim the sense that “life will go on.” BUT...My clients are NOT on a restricted diet!

Rather, they are on a gourmet “Eating-for-Health-and-Wellness” plan, in which they are encouraged to be really picky about the quality and health-giving properties of the foods they choose! I strongly feel a cancer-fighting diet should be a feast for the senses and a delight to the tastebuds, as well as being dense with nutrients! It’s not a short-term diet, but a life-long health-nourishing plan.

I don’t favor restrictive diets (that approach is far too stressful when you are dealing with all the stress of the diagnosis and treatment too). I like to focus on all the great, tasty foods that are emphasized in the eating plan, and to teach my clients the “smart” way to handle “less healthy” foods.

When a client has cravings, we find ways to choose healthier versions of these same foods, and keep portions moderate. Some “less-nourishing” foods feed our spirit or carry special memories. I don’t belief we should cut these out completely, but rather learn healthier ways to incorporate them into the diet. Just this week I gave a client the recipe for a chocolate cake to celebrate the successful completion of her breast cancer therapy. (We will try to get this recipe for out next newsletter!) Yes, the recipe contains no flour, no sugar, no artificial sweeteners; and it is a good source of protein, omega-3 fats and antioxidants (plus, the taste is outrageous).

Are French fries on the diet? Yes: cut organic skin-on potatoes (or sweet potatoes) into wedges, mist lightly with olive oil, toss with garlic and a bit of rosemary, and bake until lightly golden.

Is chocolate on the diet? Yes: small amounts of organic dark chocolate can be eaten following meals that have ample fiber, vegetables and protein.

Is pizza on the diet? Sure: start with a whole-grain spelt crust (high in fiber, can purchase frozen at the health food store), add tomato sauce (rich in lycopene), pile high with vegetables (onions, mushrooms, peppers, spinach, artichokes, garlic). Top with a bit of parmesan or organic cheese (optional) and sprinkle liberally with parsley, basil, marjoram and oregano.

Yum! Are you getting hungry now? I love the challenge of a client saying, “I really love to eat blank, (fried chicken, perhaps?),” and teaching her how to do so in the healthiest possible way.

I also encourage non-food sources of indulgence: massages, a bubble bath or soak in the hot tub, a great novel, a Qi gong class, the Sunday crossword puzzle, a vacation, a concert, a long chat on a phone with a close and supportive friend...

How we choose to eat represents how we choose to nourish our own health. Many of my clients have been so busy in their lives, with work, family and social obligations, they have neglected basic self care. Learning to self-nurture is a gift many cancer patients take away from their diagnosis. The commitment to an on-going healthy diet is a great way to care for our own health.

What about soy? Should women supplement with soy or not? Is tofu bad for you or a smart breast cancer prevention strategy? Why is this so controversial?

(Here is an article Jeanne wrote about Soy)

—Soy contains constituents that have been called phytoestrogens. These compounds are perhaps mis-named, because they do not contain estrogen, but rather are Selective Estrogen Receptor Modulators (SERMs), just as tamoxifen is a SERM. In fact, the potency of phytoestrogens has been estimated as 500-1,000 times weaker than human estrogen [Leffers et al., 2001].

Consider the following analogy: The estrogen receptor is like a keyhole in a locked door, and estrogen is the key that opens that door and “turns on" growth-promoting effects in the cell. However, among dozens of keys, you might find some that fit into the keyhole but do not work to turn the lock and open the door.

This analogy appears to describe phytoestrogens quite well: they are like keys that fit into the lock, but generally do not open the door or "turn on" the estrogenic effect. The capacity of soy compounds to dock on the estrogen receptor prevents human estrogens and xenoestrogens (environmental chemicals that act as highly potent estrogens) from binding to the receptor and promoting growth [Huber 2000]!

This last point is very important, because a primary benefit of soy phytoestrogen are their ability to COMPETE with estrogen and xenoestrogens.

One of the reasons for the controversy surrounding soy phytoestrogens is the poor quality of the many research studies that have been done. During the past decade, there have been more than 150 published articles in the medical literature on the topic of soy phytoestrogens and breast cancer. The vast majority of these studies have reported that soy genistein inhibits the proliferation of cancer cells.

However, a small minority of studies have found that soy genistein may stimulate the proliferation of estrogen-dependent cancer cells under certain conditions. The majority of these studies suffer from poor design or flawed research methodology (I offer a critical evaluation of these studies in an article available on my website

As an example: in mice with ovaries removed (i.e., estrogen deficient state), soy can promote an estrogenic effect. When these same mice are given both estrogen (or xenoestrogens) and soy, the soy offers a protective effect. Remember, the benefit of soy phytoestrogens comes from COMPETITION with estrogen (and xenoestrogens).

Some nutrition authorities have reasoned that soy may be protective in pre-menopausal women, but risky in post-menopausal women. But after menopause, few women really exerience low estrogen (due to exposure to xenoestrogens and an increase tissue levels of estrogen due to upregulation of the aromatase enzyme).

On the other hand, there does appear to be a window of opportunity, in that soy consumption during puberty and early adulthood ( a time of breast tissue maturation) appears to be most protective against later development of breast cancer. Epidemiological studies have reported that the risk of developing breast cancer is reduced 5- to 10-fold in women who regularly consume soy foods [Wu et al., 1998; Fournier et al., 1998; Stevens 1997; Messina & Barnes 1991].

Also of note: a study in the journal Carcinogenesis looked at the effect of soy processing on its impact on breast cancer. Animals with mammary cancer were fed soy from differing sources—from unprocessed soy foods to highly processed soy protein isolates—all at the same dose level of genistein. While unprocessed soy posed no risk, highly processed soy appeared to promote cancer growth.

With all the focus on the “phytoestrogen” effects of soy, the other beneficial effects of soy against cancer are often overlooked. Soy compounds have been shown to:

• Arrest the cell cycle of cancer cells (induce cytostasis)
• Promote differentiation
• Induce programmed cell death (apoptosis)
• Modify gene expression, down-regulating oncogenes (like Her2neu) and increasing tumor suppressor genes (like p53 and p21)
• Have Anti-angiogenesis actions
• Help inhibit invasion and metastasis

Putting all this together: I favor intake of Tradiational whole soy foods (miso, tempeh, tofu and soymilk), particularly in women who have eaten soy earlier in life and whom are likely to have excess estrogen or significant xenoestrogen exposure. Supplements of high dose soy isoflavones, or processed soy protein isolates, are best avoided.

By the way, it's interesting to note that, while soy foods have been "singled out" for attention, dozens of other common foods are rich in phytoestrogens, including legumes (black beans, lentils, peas, kidney beans, pinto beans, etc.), whole grains, nuts, seeds (especially flax seeds), spinach, cabbage, sprouts, apples, celery, parsley, kudzu, red clover, licorice, thyme, oregano, turmeric, hops, and many other herbs/spices.

Nature has provided these foods as a "checks and balances" system to help regulate the effects of estrogen in mammals and humans. Even if you choose to avoid soy, it's nearly impossible to eat a healthy diet that completely avoids phytoestrogens.

BHP:  What is the single most important nutritional issue women should be aware of?

-There are several great answers to this question, but I feel the recent advances in nutrigenomics are monumental, and will lead us to huge changes in how we view nutrition. For decades, we’ve used a model of human nutrition that likens our bodies to “machines” (e.g., an automobile) and our food to the fuel (the “gasoline” used to run the car). Under this model, differences between healthy foods and refined processed foods are difficult to long as you are offering “fuel,” it doesn’t seem to matter the quality of that fuel. Recent advances show us how archaic this approach is. We are learning that food nutrients actually have the ability to “talk” to our genes, and to modify gene expression.

• Leonard Augenlight has shown in a brilliant study that feeding nutrient-poor diets to animals promotes changes in the expression of over 2,000 genes, creating a gene profile moving toward cancer, and that subsequently feeding these same animals a healthy diet reverses these gene changes.

• Karen Auborn and colleagues have demonstrated the ability of a phytonutrients in brassica-family vegetables to inhibit the induction of over 100 genes upregulated by estrogen that are involved in tumor proliferation and growth in response to estrogen.

• Selenium can influence BrCa1 and BrCa2 genes, reducing to normal the rapid accumulation of DNA damage that occurs in women with BrCa1 and 2 mutations.

• Lillian Thompson et al., published an ingenious study in which women with newly biopsied breast cancer were fed flaxseed (in muffins vs flax-free “placebo” muffins) during the interval between biopsy and surgery. At surgery, several markers of tumor aggressiveness were compared and flax consumption was shown to downregulate her-2/neu, increase apoptosis (cell death) and slow proliferation rates (ki-67)!

• New research is demonstrating many nutrients modify the expression of the Her-2/neu gene, including: oleic acid (from olive oil), DHA in fish oil, flaxseed lignans, soy genistein and quercetin (found in green apples and onions).

I think we are coming to the understanding that FOOD IS MEDICINE. And this is great, because it offers each of us the opportunity to nourish our health, to be active participants in creating wellness rather than waiting for illness to develop or progress.

Back to the car/gas analogy I mentioned earlier: what we are learning is that the “fuel” we choose actually alters who we are on the level of gene expression. It’s as if by choosing the highest-grade fuel, you could transform your beat-up clunker into a Rolls Royce or Mercedes-Benz!

The single most important nutritional issue? You are not stuck with the genetic-luck-of-the-draw you were born with. Genes expression is influenced by diet. And you can talk to your genes by choosing a whole food, unprocessed, unrefined plant-based diet rich in organic fruits and vegetables (of every rainbow color).

Do you have anything else you would like to share?

-The work your organization is doing is essential. Thanks for the opportunity to share this information with your readers! My website offers additional articles and slide presentations from my speaking engagements that may be helpful.

Here are links to Jeanne's Website  alos check out the Publication page.

Jeanne is an amazing resource for women who are facing breast cancer or who have had breast cancer and want to help prevent a reoccurance.  If you call her, please let her know that we sent you!





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