home - who we are - what's new - getting started - community - RSS Feed

The George Mateljan Foundation, a not-for-profit foundation with no commercial interests, is a new force for change to help make a healthier you and a healthier world.

eating healthycooking healthyfeeling great
Printer friendly version
Breast cancer

Summary

Americans have one of the highest breast cancer rates in the world. One's risk for breast cancer is related to one's lifetime exposure to estrogen-like substances. These include any of the natural and man-made chemicals to which the body responds similarly (but sometimes much more strongly) than it would respond to estrogen.

While one out of eight American women develop breast cancer, the rate of breast cancer in Japan is about one-fifth of that in the United States. Researchers attribute much of this discrepancy to differences between the standard American diet and the low-fat, nutrient-dense native diet and of the traditional Japanese diet.

There is tremendous controversy regarding the role of dietary fats in the development and progression of breast cancer. However, evidence is building to show that the types of fats you eat and levels of other nutrients in your diet may greatly influence how your body processes estrogen-like substances, which clearly affect the risk for breast cancer.

Breast cancer survivors who eat 5 or more servings daily of vegetables and fruits, and exercise moderately, can cut their risk of dying from breast cancer almost in half, even if significantly overweight, shows a study just published in the June 2007 issue of the Journal of Clinical Oncology.

Researchers at the Cancer Prevention and Control Program, San Diego Cancer Center, La Jolla, CA, enrolled 1,409 women diagnosed and treated for early-stage breast cancer between 1991 and 2000, and followed them through December 2005.

The combination of consuming 5 or more daily servings of vegetables and fruits with regular moderate exercise (equivalent to walking 30 minutes, 6 days a week), was associated with a significant survival advantage - a 44% reduction in risk in obese as well as nonobese women. If you've been diagnosed with breast cancer, you can greatly improve your odds of living a long and healthy life simply by enjoying a daily half-hour's walk and delicious meals featuring the World's Healthiest Foods.

Eat more

  • Cold water fish such as salmon, tuna, herring, mackerel and halibut for their beneficial omega 3 fatty acids
  • Eggs
  • Olive oil
  • Turmeric
  • Garlic
  • Soy foods
  • Flaxseeds
  • Legumes
  • Whole grains
  • Sea vegetables
  • Organically grown Brassica vegetables including cabbage ,broccoli, kale, mustard greens and Brussels sprouts
  • Fresh fruit especially cranberries and and citrus
  • Apples

Avoid well done meat, polyunsaturated fats, caffeine-containing foods and beverages and alcohol.

Click for: Food Sensitivities Allergy Avoidance Diet

Description

One out of eight American women will develop breast cancer. It is interesting to note that among Japanese women living in Japan, the rate of breast cancer is about one-fifth that in the United States.

However, among Japanese women who move to the West, the rate increases until by the third generation after immigration, the risk of breast cancer is almost equal. Researchers explain this rise by noting that most "westernized" Japanese adopt the standard American diet, thereby losing the advantages of their low-fat, nutrient-dense native diet and of their traditional lifestyle.

Related testing:

  • Breast self-examination (monthly)
  • Mammograms as recommended by your doctor
  • Sex hormone evaluation
  • Gene testing (uncommon but becoming more common)
Dietary Causes

The contents of your diet can exert profound daily effects on the way your body absorbs, responds to, transforms, recycles, and excretes estrogen-like substances.

In recent population studies, investigators have explored diets from around the world to determine the components that most affect breast cancer risk. Dietary factors associated with a higher risk include:

  • Animal products
  • Meat
  • Total fat
  • Saturated fat
  • Dairy
  • Refined sugar
  • Total calories
  • Alcohol

Dietary factors associated with a lower risk include:

  • Fish, especially those rich in omega-3 fatty acids
  • Eggs
  • Fruits, especially citrus fruits and cranberries
  • Olive oil
  • Whole grains
  • Soy and other legumes
  • Cabbage
  • Vegetables
  • Fruits

Dietary Fat

There is tremendous controversy regarding the role of dietary fats in the development and progression of breast cancer. However, evidence is building to show that the types of fats you eat and levels of other nutrients in your diet may greatly influence how your body processes estrogen-like substances, which clearly affect the risk for breast cancer. Examples may include:

  • Excess intake of non-essential fats in relation to essential omega-3 fatty acid intake
  • Excess intake of non-essential fats in relation to dietary fiber intake
  • Excess intake of non-essential fats in addition to excess alcohol intake
  • Excess intake of non-essential fats in relation to antioxidant intake
  • Excess intake of non-essential fats in relation to phytoestrogen intake

Coffee, tea, and chocolate

These enjoyable and addictive substances have unfortunate effects on estrogen metabolism. The stimulants in these foods compete with estrogen for removal from the body; the more coffee, tea, or chocolate you consume, the harder it is for your body to excrete estrogens!

Alcohol

Estrogen levels and the risk for breast cancer increase as alcohol intake increases, especially with aging. These effects may be related to reductions in normal detoxification and excretion or even deeper changes in cell function.

Non-organic foods

Another very controversial topic! There is increasing concern over the use of certain agricultural chemicals, including:

  • Hormones that encourage livestock growth but may leave residues in animal flesh
  • Pesticides and herbicides, some of which act as "environmental estrogens"
  • Fertilizers that may contain high levels of heavy metals
  • Antibiotics that may leave residues in animal flesh

Well-done meats

Studies have shown that the consumption of well-done meats (such as burgers, steak, bacon) may increase risk of developing breast cancer by almost 5 times.

Nutrient Needs

Cold-water fish and omega-3 essential fats

Fish, particularly cold-water fish such as salmon, mackerel, halibut, and herring, are rich sources of the omega-3 fatty acids . These essential fats have shown tremendous anticancer effects and are especially important in protection against breast cancer.

Women whose diets provide a good supply of omega-3 fats are significantly less likely to develop breast cancer than women consuming little of these essential fatty acids, suggests a Japanese study published in the International Journal of Cancer (Kuriki K, Hirose K, et al.).

Body levels of omega-3s can be evaluated by looking at a woman's diet and also by measuring the amounts of these fats, such as EPA and DHA, in her red blood cells (erythrocytes). In this study, researchers did both.

Japanese women whose diets provided the most omega-3 fats, largely from fish, were found to have a 49% reduced risk of breast cancer compared to women with the least dietary intake of omega-3s.

When omega-3 levels in the women's erythrocytes were evaluated, women with the highest erythrocyte levels of EPA were found to have a 73% lower risk of breast cancer; those with the highest erythrocyte levels of DHA had an amazing 94% reduction in breast cancer risk; and those whose levels of ALA were highest had an 89% reduction in risk.

In another study of 121 women with breast cancer, the single most significant difference between the women whose cancer spread (metastasized) and those whose hadn't was their levels of alpha linolenic acid, an omega-3 essential fatty acid commonly found in flaxseeds and flaxseed oil.

In a laboratory study, breast cancer cells that were exposed to an omega-3 essential fatty acid showed increases in their contents of benign, cancer-protective estrogen and decreases in their levels of pro-inflammatory, cancer-promoting estrogen. Such findings are extremely important, since the main cause of death in breast cancer patients is metastasis to other tissues.

Recent in vitro (test tube) evidence suggests that these beneficial effects are related to the fact that when omega-3s are consumed in the diet, they are incorporated into cell membranes where they promote cancer cell apoptosis via several mechanisms including: inhibiting a pro-inflammatory enzyme called cyclooxygenase 2 (COX 2), which promotes breast cancer; activating a type of receptor in cell membranes called peroxisome proliferator-activated receptor (PPAR)-ă, which can shut down proliferative activity in a variety of cells including breast cells; and, increasing the expression of BRCA1 and BRCA2, tumor suppressor genes that, when functioning normally, help repair damage to DNA, thus helping to prevent cancer development.

In contrast, the omega-6 fatty acids found in most animal products and in common vegetable oils (such as corn, safflower, and sunflower) are positively associated with breast cancer. Aachidonic acid, an omega-6 fatty acid, activates 11 genes that direct the production of numerous pro-inflammatory compounds including nuclear factor-kappaB (NF-kappaB), COX-2, TNF-alpha, IL-6, IL-8, PPARgamma, and ICAM-1, while also increasing the synthesis of the proinflammatory E2 series of prostaglandins.

Practical Tip: Include a variety of omega-3-rich foods in your daily diet. Flaxseeds, walnuts, and omega-3-rich eggs are excellent sources of alpha linolenic acid (ALA), while EPA and DHA are concentrated in cold-water fish, such as salmon, sardines, tuna, cod and halibut.

Research published in the November 2005 issue of the International Journal of Cancer has revealed yet another way in which the omega-3 fatty acids found in cold water fish-docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)-curb the growth of breast cancer cells.

In these experiments, mice were fed diets rich in either omega-3 (fish oil) or omega-6 (corn oil) fatty acids, after which breast cancer cells were implanted. Three weeks later, tumor volume and weight was significantly lower in mice on the omega-3 rich diet.

Why? As mentioned above, dietary fatty acids are incorporated into cell membranes, and the type of fatty acids dictates how a cell responds and grows. Researchers found that omega-3 fatty acids affect cell growth by activating an enzyme called sphingomyelinase, which then generates the release of ceramide, a compound that induces the expression of the human tumor suppressor gene p21, which ultimately causes cancer cell death.

In the lab culture experiments, when cells were treated with DHA or EPA, sphingomyelinase activity increased by 30-40%, and breast cancer cell growth dropped 20-25.

Oleic acid, the primary fatty acid in olive oil

Olive oil may be the key reason that eating a Mediterranean diet reduces breast cancer risk, suggests a laboratory study published in the January 2005 issue of the Annals of Oncology. Oleic acid, the main monounsaturated fatty acid in olive oil, has been shown to reduce the expression of the Her-2/neu oncogene, which is associated with the aggressive growth of breast cancer tumors. High levels of Her-2/neu are found in one-fifth of breast cancers, especially those that are resistant to treatment.

In this study, when Menendez and his colleagues from Northwestern University in Chicago exposed two strains of aggressive breast cancer cells to oleic acid, levels of Her-2/neu dropped 46%. When they combined oleic acid with lower levels than are normally used of Herceptin, a drug used to treat breast cancer, oleic acid greatly enhanced the effectiveness of the drug, dropping Her-2/neu expression as much as 70%. The end result: oleic acid promoted the apoptotic cell death (suicide) of aggressive, treatment resistant breast cancer cells.

A human study adds to the evidence that olive oil is a key factor in the lowering of breast cancer risk associated with a Mediterranean diet. Results of this two-year long study involving 755 women in the Canary Islands suggest that monounsaturated fat and, specifically, olive oil exert a protective effect against breast cancer.

Study participants consuming the most monounsaturated fat were found to have a 48% lower risk of breast cancer compared to women whose intake of monounsaturated fat was lowest.

Among women consuming the most olive oil, specifically, the risk of breast cancer was even lower. Compared to those consuming the least olive oil, women whose daily intake of olive oil was at least 8.8 grams, the equivalent of just .65 tablespoon/day, had a 73% lower risk of breast cancer risk!

Turmeric

Epidemiological studies have linked the frequent use of turmeric to lower rates of breast, prostate, lung and colon cancer, and earlier laboratory experiments have shown curcumin can prevent tumors from forming. Now, new research conducted at the University of Texas suggests that even when breast cancer is already present, curcumin can help slow the spread of breast cancer cells to the lungs in mice.

In this study, published in the September 2005 issue of Biochemical Pharmacology, human breast cancer cells were injected into mice, and the resulting tumors removed to simulate a mastectomy.

The mice were then divided into four groups. One group received no further treatment and served as a control. A second group was given the cancer drug paclitaxel (Taxol); the third got curcumin, and the fourth was given both Taxol and curcumin.

After five weeks, only half the mice in the curcumin-only group and just 22% of those in the curcumin plus Taxol group had evidence of breast cancer that had spread to the lungs.

But 75% of the mice that got Taxol alone and 95% of the control group developed lung tumours.

How did curcumin help? "Curcumin acts against transcription factors, which are like a master switch," says lead researcher, Bharat Aggarwal. "Transcription factors regulate all the genes needed for tumors to form. When we turn them off, we shut down some genes that are involved in the growth and invasion of cancer cells."

In another laboratory study of human non-Hodgkin's lymphoma cells published in the September 2005 issue of Biochemical Pharmacology, University of Texas researchers showed that curcumin inhibits the activation of NF-kappaB, a regulatory molecule that signals genes to produce a slew of inflammatory molecules (including TNF, COX-2 and IL-6) that promote cancer cell growth. In addition, curcumin was found to suppress cancer cell proliferation and to induce cell cycle arrest and apoptosis (cell suicide) in the lung cancer cells.

Early phase I clinical trials at the University of Texas are now also looking into curcumin's chemopreventive and therapeutic properties against multiple myeloma and pancreatic cancer, and other research groups are investigating curcumin's ability to prevent oral cancer.

Garlic

The phytochemical responsible for garlic's pungency may also help prevent cancer by inhibiting the effects of a carcinogen produced in meat cooked at high temperatures, suggests research presented July 2005 at the American Association for Cancer Research's Frontiers in Cancer Prevention Research meeting in Baltimore, MD.

Cooking protein-rich foods like meats and eggs at high temperatures produces a chemical called PhIP. A cancer-causing heterocyclic amine, PhIP is thought to be one reason for the increased incidence of breast cancer among women who eat large quantities of meat because it is rapidly transformed into DNA-damaging compounds.

Diallyl sulphide (DAS), an organosulfur compound that gives garlic its unique flavor, has been shown to inhibit the transformation of PhIP into carcinogens. DAS blocks this transformation by decreasing the production of the liver enzymes (the Phase I enzymes CYP1A1, CYP1A2 and CYP1B1) that transform PhIP into activated DNA-damaging compounds.

In addition, DAS signals the genes responsible for producing two protective antioxidant enzymes, (glutathione-S-transferase (GST) and superoxide dismutase (SOD), which help protect the body against harmful compounds such as those produced from PhIP.

Ronald Thomas and a team of researchers at Florida A&M University in Tallahassee treated human breast epithelial cells with equal amounts of PhIP and DAS separately, and the two together, for periods ranging from three to 24 hours.

When PhIP was used alone, it caused the production of a cancer-causing enzyme at every time interval, up to 40-fold, while DAS completely inhibited PhIP from becoming carcinogenic.

Thomas and colleagues found that when DAS and PhIP were added to cell cultures, over the next 24 hours, DAS caused a time dependent increase of protective SOD of 3, 25, 29, and 39-fold, and similar results were seen with increased GST production.

These findings suggest that making garlic, onion, chives and other allium vegetables, all of which contain DAS, a staple part of your healthy way of eating may help in preventing breast cancer induced by PhIP in well-done meats. And enjoying these DAS-rich foods may help protect the men you love as well: Consumption of allium vegetables has also been associated with a reduced risk of prostate cancer.

Vitamin C

A high intake of vitamin C has been shown to reduce the risks for virtually all forms of cancer, including leukemia, lymphoma, and lung, colorectal, and pancreatic cancers as well as sex hormone-related cancers like breast, prostate, cervix, and ovarian cancers.

Vitamin C is your body's first and most effective line of antioxidant protection. Vitamin C protects cell structures like DNA from damage, it helps the body deal with environmental pollution and toxic chemicals, it enhances immune function, and it inhibits the formation of cancer-causing compounds in the body (such as nitrosamines).

Vitamin C functions in the body's watery environments, which complements vitamin E's protection of the body's fatty environments. Vitamin C is also responsible for regenerating damaged (oxidized) vitamin E in the body. In a sense, these nutrients are like policemen that patrol different neighborhoods. Most of the scientific evidence supporting vitamin C is based on a high vitamin C intake from foods that are also rich in carotenoids and other nutrients that protect against cancer.

Vitamin E

Vitamin E, also known as alpha-tocopherol, is one of the most important fat-soluble antioxidants in the human body. Without the protection of vitamin E, your cells (and especially their delicate membranes) would suffer severe damage. As with vitamin C, studies have shown that a high vitamin E intake appears to offer significant protection against cancer.

Over a dozen such studies have shown that low levels of vitamin E (especially when selenium levels are also low) are associated with an increased risk of certain types of cancer, particularly colon, prostate, breast, and lung cancer. In contrast, higher levels of vitamin E appear to exert considerable immune enhancing and anti-tumor effects.

One of the key anticancer effects of vitamin E may be its positive impact on the immune system. As we age, immune function tends to decline, partly due to accumulated damage to the membranes of white blood cells, especially the type called "T cells." Age-related decline in T cell function appears to be a factor in many diseases, including cancer, arthritis, autoimmune diseases, and infections. Several studies have shown that antioxidants are crucial for preserving T cell function and for keeping the immune system humming.

Selenium

Selenium, a trace mineral, is a vital antioxidant that works closely with vitamin E and vitamin C to prevent free radical damage to cell membranes. Low levels of selenium have been linked to a higher risk for virtually all cancers. In contrast, high intakes of selenium may offer significant protection against several cancers, especially cancers of the lung, colon, prostate, stomach, esophagus, and liver, and appear to lower the rate of cancer-related death. Selenium supports all components of the immune system, and deficiency lowers resistance to infection, whereas high intakes stimulate immune cell function.

Carotenoids

Pigments known as carotenoids are responsible for giving foods their red, orange, and yellow hues. (The word "carrot" is derived from the word "carotene.") Carotenoids occur naturally in the cell membranes of organisms that convert sunlight into energy. In fact, without carotenoid protection, these organisms would be destroyed by the oxidative damage that results during the process of photosynthesis.

In humans, carotenoids act as antioxidants. Our bodies also convert certain carotenoids into vitamin A. Of the over 600 known carotenoids, about 30 to 50 (such as beta-carotene and alpha-carotene) are believed to have some degree of vitamin A activity. Other carotenoids (such as lutein and lycopene) lack vitamin A activity yet are very powerful antioxidants.

Food sources of a variety of carotenoids include leafy greens, carrots, sweet potatoes, squash, spinach, bell peppers, corn, watermelon, potatoes, apples, peaches, tomatoes, apricots, yeast, cherries, persimmons, papayas, lemons, oranges, prunes, paprika, pink grapefruit, mushrooms, and saffron.

Folate (Folic Acid)

This nutrient from the B-vitamin family is necessary for controlling normal cell growth and division. Women who have a high intake of folate have a lower risk for breast cancer, and women with a lower intake have a higher risk, particularly if they consume an average of one-half of an alcoholic drink daily.

Yet another finding to come out of the Nurses' Health Study indicates that eating enough folate- and vitamin B6-rich foods may significantly reduce the risk of developing breast cancer. Folate, in particular, may be especially important for women at higher risk of developing breast cancer because of higher alcohol consumption.

In this study, published the Journal of the National Cancer Institute (March 2003), a possible association between blood levels of folate and other vitamins and breast cancer was investigated in almost 33,000 women, who were followed for 17 years. In general, women consuming the most folate had a 27% lower risk of developing breast cancer compared to those eating the least folate-rich foods. In women who consumed approximately 1 alcoholic drink per day, folate consumption was highly protective, reducing their risk by 89% compared to women consuming alcohol daily but eating the fewest folate-rich foods. Eating foods rich in vitamin B6 was also protective, reducing risk of breast cancer by 30% in women consuming the most vitamin B6-rich foods compared to those consuming the least.

In a prospective 9.5 year study of 11,699 postmenopausal women aged 50 or older, women eating the most folate-rich foods had a 64% reduced risk of invasive breast cancer compared to those eating the least. Excellent sources of folate include romaine lettuce, spinach, asparagus, turnip greens, mustard greens, calf's liver, parsley, collard greens, broccoli, cauliflower beets, and lentils. (Ericson U, Sonestedt E, et al., Am J Clin Nutr.)

In another study appearing in the Journal of the National Cancer Institute (March 2004), folate from foods was also shown to reduce the risk of ovarian cancer. Researchers analyzed data on 61,084 Swedish women, aged 38 to 76 years, who were followed from 1987 through June 2003. Overall, women consuming the most folate-rich foods were found to have a 33% lower risk of epithelial ovarian cancer, but if they were consuming more than two drinks of alcohol per week, those also eating the most folate-rich foods were 74% less likely to develop ovarian cancer compared to women drinking this amount but consuming the least folate in their diets.

Excellent sources of vitamin B6 include: bell peppers, turnip greens, and spinach.

Dietary Fiber

Certain types of dietary fiber (such as that found in whole grains, legumes, nuts, and seeds) bind to estrogen-like substances in the digestive tract and prevent them from re-entering and re-affecting the body. These kinds of fiber also promote the formation of a blood protein (called sex hormone binding globulin, or SHBG) that helps keep estrogen-like substances in a less-active form in the blood and help the body excrete metabolized estrogens.

Fiber from Whole Grains and Fruit Protective against Breast Cancer

When researchers looked at how much fiber 35,972 participants in the UK Women's Cohort Study ate, they found a diet rich in fiber from whole grains and fruit offered significant protection against breast cancer for pre-menopausal women. (Cade JE, Burley VJ, et al., International Journal of Epidemiology).

Pre-menopausal women eating the most fiber (>30 grams daily) more than halved their risk of developing breast cancer, enjoying a 52% lower risk of breast cancer compared to women whose diets supplied the least fiber (<20 grams/day).

Fiber supplied by whole grains offered the most protection. Pre-menopausal women eating the most whole grain fiber (at least 13 g/day) had a 41% reduced risk of breast cancer, compared to those with the lowest whole grain fiber intake (4 g or less per day).

Fiber from fruit was also protective. Pre-menopausal women whose diets supplied the most fiber from fruit (at least 6 g/day) had a 29% reduced risk of breast cancer, compared to those with the lowest fruit fiber intake (2 g or less per day).

Practical Tip: As the following table shows, it's surprisingly easy to enjoy a healthy way of eating that delivers at least 13 grams of whole grain fiber and 6 grams of fiber from fruit each day.

Food Fiber Content in Grams
Oatmeal, 1 cup 3.98
Whole wheat bread, 1 slice 2
Whole wheat spaghetti, 1 cup 6.3
Brown rice, 1 cup 3.5
Barley, 1 cup 13.6
Buckwheat, 1 cup 4.54
Rye, 1/3 cup 8.22
Corn, 1 cup 4.6
Apple, 1 medium with skin 5.0
Banana, 1 medium 4.0
Blueberries, 1 cup 3.92
Orange, 1 large 4.42
Pear, 1 large 5.02
Prunes, 1/4 cup 3.02
Strawberries, 1 cup 3.82
Raspberries, 1 cup 8.36

*Fiber content can vary between brands.

Source: esha Research, Food Processor for Windows, Version 7.8

Fruit and Cereal Fiber Protective against Postmenopausal Breast Cancer

Results of a prospective study involving 51,823 postmenopausal women for an average of 8.3 years showed a 34% reduction in breast cancer risk for those consuming the most fruit fiber compared to those consuming the least. In addition, in the subgroup of women who had ever used hormone replacement, those consuming the most fiber, especially cereal fiber, had a 50% reduction in their risk of breast cancer compared to those consuming the least. (Suzuki R, Rylander-Rudqvist T, et al., Int J Cancer.)

Fruits richest in fiber include apples, dates, figs, pears and prunes. When choosing a high fiber cereal, look for whole grain cereals as they supply the most bran (a mere 1/3rd cup of bran contains about 14 grams of fiber).

Phytoestrogens-Soyfoods, Flaxseeds, and More

Phytoestrogens are naturally occurring food nutrients that seem to mitigate some of the effects of estrogen-like substances on hormone-sensitive areas of the body (such as the breasts). Food phytoestrogens include:

  • Isoflavones (like genistein and daidzein), which come from soy, beans, peas, clover, licorice root, alfalfa, and kudzu
  • Lignans, which come from flaxseed, rye, wheat, and sea vegetables
  • Some types of flavonoids (like rutin, quercetin, and resveratrol), which are especially plentiful in citrus fruits, grapes, black and green teas, nut skins, and onions

Special note on Soyfoods

Since the 1970s, there has been a marked increase in the consumption of traditional soy foods such as tofu, tempeh, and miso and in the development of innovative soyfoods like soymilk, soy hotdogs, soy sausage, soy cheese, and soy frozen desserts.

One reason for the increase in soy consumption is considerable evidence indicating possible anticancer effects of soyfoods, particularly in relation to hormone-sensitive cancers like breast and prostate cancer. Isoflavones have been shown to act as antioxidants, reduce high estrogen levels, prevent the growth of new blood vessels around tumors, prevent tumor cells from growing and dividing.

Population studies have found that soy consumption may help reduce a woman's risk of developing breast cancer. Women in Asian countries traditionally consume more soy than most women in Western countries and have a lower incidence of breast cancer (and almost no menopausal symptoms). Other studies show that when healthy women add soy products to their diets, their levels of estrogen and other hormones fall.

Recently published research involving nearly 22,000 Japanese women-the Japan Public Health Center-Based Prospective Study on Cancer and Cardiovascular Diseases-has led further support to the relationship between a diet high in isoflavone-rich soy foods, particularly miso, and a significantly lower risk of breast cancer. The women, who ranged in age from 40 to 59 years, filled out a dietary questionnaire that included questions about soy consumption and were followed for 10 years. Whether pre- or postmenopausal, women who reported eating three or more cups of miso soup per day had a 40% lower risk of developing breast cancer compared to women who reported consuming less than one cup per day. Women with the highest intakes of isoflavones-compounds in soyfoods that can bind to estrogen receptors in the body and block out human estrogen, thus lessening its effects-had a 54% lower risk of developing breast cancer compared to those whose intake of isoflavones was lowest.

A variety of soyfoods commonly eaten in the Asian diet contain isoflavones including tofu, miso, soymilk, soy sauce, soy flour, green or dried soybeans, soybean sprouts and a fermented soy food called natto. Almost 75% of the women reported eating miso soup daily, and of these 34% ate three or more cups of miso soup per day. More than 45% reported eating soy foods other than miso daily. The average intake of isoflavones among participants in this study was calculated to be about 700 times higher than that of Caucasians in the United States.

In addition to isoflavones, soyfoods contain other nutrients (such as the special protein, fibers, and fats in soy) that may provide additional protection against breast cancer, heart disease, and other diseases. With the abundance of convenient modern soyfoods, adding soy to your menus is an easy and delicious way to replace animal proteins and saturated fats in your diet.

For Cancer Protection, Eat Whole Soy Foods, Not Purified Soy Products

A study published in the June 2004 issue of Carcinogenesis suggests that not only is the cancer-preventive ability of soy foods markedly reduced in highly purified soy products and supplements, but that such processed foods can stimulate the growth of pre-existing estrogen-dependent breast tumors.

Soy foods contain complex mixtures of bioactive compounds that interact with one another to promote health, while the partially purified isoflavone-containing products consumed in the U.S. may have lost many of the biologically active components in whole soy foods. "These partially purified isoflavone-containing products may not have the same health benefits as whole soy foods," noted William G. Helferich, professor of food science and human nutrition at the University of Illinois at Urbana-Champaign and one of the study's primary authors.

In the study, mice were divided into four groups, one of which received no soy and served as the control group, while the others were given either whole soy flour, soy extract, a mixture of isoflavones, or genistin in pure form. Despite the fact that all groups, except the control group, received an equal amount of the soy isoflavone genistein, "as bioactive compounds were removed, we observed an increase in estrogen-dependent tumor growth," said Helferich.

In the mice given minimally processed soy flour, a form of soy comparable to the whole soy foods consumed in the Asian diet, tumors neither grew nor regressed. But in the mice given dietary soy products containing isoflavones in more purified forms, the tumors grew. "These products are similar to the materials used in isoflavone-containing dietary supplements, which is how many Americans consume these compounds," Helferich noted.

The take-home message for women, especially postmenopausal women with estrogen-responsive breast cancers who are looking for alternatives to HRT:

Avoid processed soy products and supplements that contain isoflavones in more purified forms. Choose minimally processed whole soy foods such as endamame, whole soy flour, tofu or tempeh.

PLEASE NOTE: Our support of soy foods in the case of breast cancer is focused on prevention rather than treatment. While there is little debate about soy's ability to help prevent breast cancer, it's use in treatment of the disease is still a matter of much debate. We haven't seen any organizations recommending unrestricted intake of soy in treatment of breast cancer, and we have seen several suggestions that soy be consumed only in its natural food forms (versus supplemental forms) if being consumed at all by persons with breast cancer. Level of soy intake prior to the onset of breast cancer, and specific details involving estrogen metabolism and hormonal balance can be important factors in determining the usefulness of soyfoods in breast cancer treatment - a determination that needs to be made by a qualified member of a cancer treatment team.

Special note on Flaxseeds

Besides providing high levels of essential fats, flaxseeds are also among the most abundant sources of lignans. These are specialized fibers that may help block the cancer-promoting effects of estrogens on breasts. And, like fiber, they also promote the formation of SHBG and keep estrogen-like substances in a less active form in the blood and help the body excrete metabolized estrogens.

In one recent study, researchers followed 28 postmenopausal nuns for a year and tracked blood levels of two cancer-related estrogens. In addition to their normal diets, the nuns consumed flaxseed daily. Levels of "bad" estrogens fell in the women taking ground flaxseed but remained stable in the women not taking flaxseed.

In a study published in the February 2004 issue of the American Journal of Clinical Nutrition, when postmenopausal women ate a daily muffin containing either 25 grams (a little less than 1 ounce) of soy protein, 25 grams of ground flaxseed, or a placebo muffin containing neither for 16 weeks, the estrogen metabolism of those eating flaxseed, but not soy or placebo, was altered in several important protective ways:

  • Levels of 2-hydroxyestrone, a less biologically active estrogen metabolite thought to be protective against breast cancer, increased significantly.
  • The ratio of 2 hydroxyestrone (the protective estrogen metabolite) to 16alpha-hydroxyestrone (an estrogen metabolite thought to promote cancer) increased.
  • Blood levels of the estrogen fractions (estradiol, estrone, and estrone sulfate) did not change significantly-which is important since estradiol is involved in maintaining bone mass.

So what does this mean in plain English? Eating about an ounce of ground flaxseed each day will affect the way estrogen is handled in postmenopausal women in such a way that offers protection against breast cancer but will not interfere with estrogen's role in normal bone maintenance.

Because flaxseeds are so hard, ground flaxseed provides more nutritional benefits than whole flaxseeed, and is easier to digest, as well. Flaxseed is easily ground in a coffee grinder, food processor, or blender, and may be added to foods such as hot cereals, salads, or smoothies.

Brassica Family Vegetables

The members of the Brassica family vegetables (including broccoli, kale, cauliflower, cabbage, mustard, horseradish, Brussels sprouts, and broccoli sprouts) provide unique nutrients that support your body's production of "good" estrogens while decreasing the "bad" ones.

These fabulous vegetables also potently stimulate the detoxification systems of the body and act as antioxidants. It is necessary to eat significant amounts of mustard family vegetables to get all of these benefits. Fortunately, broccoli sprouts are particularly rich in these nutrients, containing 40 times as much as mature broccoli!

Cabbage may also be especially beneficial. A recent case control study published in the journal Cancer Research found that women who eat more Brassica family vegetables have a much lower risk of breast cancer. In this study of 337 women in Shanghai, China (where Brassica vegetables such as Chinese cabbage are frequently consumed), the women's urinary levels of isothiocyanates (a type of beneficial compound found in Brassica vegetables) directly correlated with their breast cancer risk. Those women with the highest isothicyanate levels (i.e., those women consuming the most Brassica vegetables) had a 45% lower risk for breast cancer compared to those with the lowest levels of isothiocyanates.

This significant protective effect is not all that surprising considering that the isothiocyanates provided by Brassica vegetables, such as cabbage, are capable of numerous breast cancer-inhibiting actions including:

  • inducing the production of Phase II enzymes in the liver, which bind to potential carcinogens and remove them from the body
  • inducing apoptosis, the self-destruct sequence the body uses to eliminate old or cancerous cells
  • beneficially affecting the way in which steroid hormones, including estrogen, are metabolized and the way in which the estrogen receptors on cells respond to the hormone
  • and preventing excessive cellular proliferation.

Another beneficial compound in Brassica vegetables, called sulforaphane, which is formed when these vegetables are chopped or chewed, is also known to trigger the liver to produce enzymes that detoxify cancer-causing chemicals, inhibit chemically-induced breast cancers in animal studies, and induce colon cancer cells to commit suicide.

A study published in the September 2004 issue of the Journal of Nutrition showed that sulforaphane also helps stop the proliferation of breast cancer cells, even in the later stages of their growth.

If you don't love Brassica vegetables, one easy way to receive the protection provided by sulforaphane is to top salads and sandwiches with broccoli sprouts. Just a single tablespoon of broccoli sprouts contains as much sulforaphane as is found in a whole pound of adult broccoli.

The association between another Brassica vegetable, cabbage, and a reduced risk of breast cancer was the focus of research presented at the American Association for Cancer Research's annual cancer prevention meeting in Baltimore, October 31, 2005. Cabbage's role as a staple vegetable in Polish cuisine may be why the breast cancer risk of Polish women triples after they immigrate to the U.S., rising to match that of U.S.-born women.

The study included hundreds of Polish women and Polish-born women in the U.S. who are part of the Polish Women's Health Study, a case-control breast cancer study. Participants were given a food frequency questionnaire that assessed their cabbage consumption when they were 12 to 13 years old and as adults.

Compared with women who ate only one serving or less of cabbage per week during adolescence, those who ate four or more servings were 72% less likely to develop breast cancer as adults.

In Poland, women typically eat an average of 30 pounds of cabbage and sauerkraut per year, while American women consume just 10 pounds per year. Polish women also traditionally eat more raw cabbage and sauerkraut in salads or as a side dish.

Although the lowest rate of breast cancer was found among women who consumed high amounts of raw- or short-cooked cabbage during adolescence, high consumption during adulthood also provided significant protection even among women who had eaten little cabbage during adolescence.

Proper cabbage preparation and cooking methods are essential for receiving its cancer-preventive effects:

Cabbage provides anti-carcinogenic glucosinolates, which are formed by the activity of myrosinase enzymes released when cabbage is sliced or chopped. Cooking denatures the myrosinase enzyme, thus stopping the production of glucosinolates.

In the body, the breakdown products of glucosinolates are thought to affect both the initiation phase of carcinogenesis-by decreasing the amount of DNA damage and cell mutation-and the promotion phase, by blocking the processes that inhibit programmed cell death and stimulate unregulated cell growth.

Cabbage foods were categorized as raw (raw sauerkraut and fresh cabbage), short-cooked (steamed sauerkraut and cabbage), and long-cooked (hunter's stew, cabbage rolls, and pierogi). Cabbage's protective effect was seen only for raw and short-cooked cabbage, not long-cooked, which was eliminated from the analysis.

To promote the production of the most glucosinolates, slice or chop your cabbage and let sit for 5-10 minutes before cooking, and cook lightly, steaming or sautéing for 5 minutes or less.

Fresh Fruit

Fresh fruit should definitely be part of your healthy whole foods way of eating, suggests a Japanese study published in the November 2003 issue of the International Journal of Cancer. This study, which involved 2,385 breast cancer patients and 19,013 women who were cancer-free, found reductions in breast cancer risk associated with a high intake of milk and green leafy vegetables, carrots and pumpkins among pre- and postmenopausal women. Consuming fish (5 or more times per week versus less than 3 times per month) was even more protective, conferring a 25% reduction in breast cancer risk, but the most significant decrease in risk was noted among women who ate the highest amount of fresh fruit. Those eating fruit daily had a 39% lower risk of breast cancer compared to those who rarely ate fruit.

Cranberries, in particular, should be enjoyed often, and not just cranberry juice, but whole cranberries. Cranberry presscake (the material remaining after squeezing juice from the berries), when fed to mice bearing human breast cancer cells, has previously been shown to decrease the growth and metastasis of tumors, and a new study published in the June 2004 issue of the Journal of Nutrition suggests compounds in whole cranberries also inhibit prostate, skin, lung and brain cancer cells as well.

Androgen-dependent prostate cancer cells were inhibited the most (just 10 mg of a warm water extract of cranberry presscake inhibited their growth by 50%). With androgen-independent prostate cancer cells and estrogen-independent breast cancer cells, a larger amount was needed but produced the same beneficial effect (250 mg of cranberry presscake extract inhibited their growth by 50%).

Researchers concluded that the active compounds in whole cranberry prevent cancer by blocking cell cycle progression and inducing cells to undergo apoptosis (programmed cell death).

Long-lived Limonoids in Citrus Fruits Cancer-Protective

In animal studies and laboratory tests with human cells, compounds in citrus fruits called limonoids have been shown to help fight cancers of the mouth, skin, lung, breast, stomach and colon. Now, scientists from the US Agricultural Research Service have shown that our bodies can readily absorb and utilize a very long-acting limonoid called limonin that is present is citrus fruits in about the same amount as vitamin C.

In citrus fruits, limonin is present in the form of limonin glucoside, in which limonin is attached to a sugar (glucose) molecule. Our bodies easily digest this compound, cleaving off the sugar and releasing limonin.

In the ARS study, 16 volunteers were given a dose of limonin glucoside in amounts ranging from those that would be found in from 1 to 7 glasses of orange juice. Blood tests showed that limonin was present in the plasma of all except one of the subjects, with concentrations highest within 6 hours after consumption. Traces of limonin were still present in 5 of the volunteers 24 hours after consumption!

Limonin's bioavailability and persistence may help explain why citrus limonoids are potent anti-carcinogens that can continuously prevent cancerous cells from proliferating. Other natural anti-carcinogens are available for much less time; for example, the phenols in green tea and chocolate remain active in the body for just 4 to 6 hours.

Eating an apple a day may also offer significant protection against breast cancer, suggests an animal study published in the March 2005 Journal of Agricultural and Food Chemistry . When mice with breast cancer were fed the human equivalent of 1, 3 or 6 apples a day for 6 months, their tumors shrank by 25%, 25%, and 61%, respectively.

Researchers credit apples' strong protective action to the synergistic interactions among the wide variety of potent antioxidant and antiproliferative pytochemicals, including phenolics and flavonoids, they contain.

Cranberry's Phytonutrients Help Shut Down Human Breast Cancer Cells

Enjoying a handful of dried cranberries in your spinach salad or a daily glass of cranberry juice with a meal may be a delicious way to help protect yourself against breast cancer. In laboratory studies published in the December 2005 issue of Cancer Letters, cranberry phytonutrients greatly inhibited proliferation of human breast cancer cells, both by causing the cancer cells to commit suicide and by shutting down their ability to multiply by stopping their process of cellular replication before its completion.

After just 4 hours' exposure to cranberry phytochemical extracts at the low dose of just 50 milligrams per mililiter, the ratio of breast cancer cells committing suicide to total cells increased 25% compared to control cells not exposed to cranberry phytonutrients.

Cranberry phytonutrient extracts at doses from 10 to 50 milligrams per milliliter were also highly effective in stopping breast cancer cells from multiplying. After 24 hours, cancer cell replication was 6 times higher in the control breast cancer cells than in those exposed to cranberry extracts.

An Egg, Vegetable and Fruit-Rich Diet Highly Protective against Breast Cancer

New research indicates that a diet rich in eggs, salad vegetables and fresh fruit is highly protective against breast cancer.

Breast cancer incidence rates more than double in Chinese women as they migrate from China to Hong Kong to the United States, and several dietary factors, which differ between the United States and the Chinese population, including intake of soy, meat, and fruits and vegetables, have been suggested to affect breast cancer risk.

A study of 378 women with breast cancer and 1,070 age-matched controls, which was published in the January 2005 issue of Cancer Epidemiology, Biomarkers & Prevention, found two dietary choices that were strongly protective against the disease.

Women consuming the most fruit and vegetables-3.8 or more servings each day-had a 52% lower risk of breast cancer compared to women eating 2.3 or fewer servings of fruits and vegetables daily.

Eating eggs-at least 6 eggs a week-was also highly protective, lowering risk of breast cancer by 44% compared to women consuming only 2 eggs a week.

This research supports the findings of an earlier study of women living in northern Italy, which was published in the same journal in April 2004. In this study, nutritional data was collected from 8,984 women, and four dietary patterns emerged: salad vegetables (mainly raw vegetables and olive oil); western (mainly potatoes, red meat, eggs and butter); canteen (pasta and tomato sauce); and prudent (cooked vegetables, pulses, and fish).

Only the salad vegetables pattern was associated with significantly lower (34-35%) breast cancer incidence. Of special interest was the finding that overweight women (with a body mass index <25) eating the diet richest in salad vegetables and olive oil received the most protection. Among these women, breast cancer risk dropped 50%!

Looking at both studies, the message is clear: regardless of her race, a woman's best friends are fruits and vegetables!

Nutrient Excesses

Dietary Fat / Dietary Fiber Ratio

In postmenopausal women, an excess of dietary fat in relation to dietary fiber is associated with higher levels of "bad" estrogens, which increase the risk for breast cancer. This association is strongest for high levels of saturated fats (such as animal fats) and for low levels of soluble fibers (such as oats).

This relationship reflects the importance of how nutrients interact in the body - illustrating that fiber can influence the way your body metabolizes fats. It shows that a "lifestyle approach" to eating is probably more effective than just trying to cut down on fat or make other single dietary changes.

Meat

One of the most consistent findings in studies looking at diet and cancer is the positive correlation between meat consumption and the rate of cancer. In other words, the higher the intake of meat and other animal products, the higher the rate of cancer.

There are several obvious reasons for this association. Meat lacks many of the antioxidant and phytochemicals that protect us from cancer, while it contains more saturated fat and potentially carcinogenic compounds that can actually increase the risk of developing cancer.

These compounds are not a natural part of meat, but occur from the non-organic feeding of cattle and from particular ways of cooking. From non-organic feed can come pesticides, and from grilling, frying, or broiling can come heterocyclic amines and polycyclic aromatic hydrocarbons. Intake of red meat should be limited to three ounces per day, and well-done, charbroiled, cured, and fatty meats should be avoided.

Polyunsaturated fats

In a recent breast cancer study, women who consumed highly polyunsaturated fats such as sunflower oil, safflower oil, or corn oil were 20 percent more likely to develop breast cancer. In this study, the heating of cooking oil to a high temperature was associated with a 1.64 fold increased risk of lung cancer as well.

Stimulants

As noted before, caffeine-containing beverages and foods like coffee, black tea, and even chocolate can interfere with your body's normal efforts to excrete estrogen-like substances.

Alcohol

Alcohol intake is positively associated with breast cancer risk, particularly with aging and with a low intake of folic acid. Regular consumption of alcohol makes it more difficult for the liver (the body's main organ of chemical detoxification) to break down and metabolize hormones in a healthy manner.

Excess weight

Very obese people have almost twice the risk of death from breast cancer as do non-obese people.

Recommended Diet

Dietary guidelines for breast health:

  • Eat fresh and organic foods whenever possible
  • If you eat meat, focus on fish and organic game and poultry rather than red meats
  • Do eat fish, especially cold-water fish
  • Enjoy at least 6 eggs each week
  • Eat whole-grain rice, pastas, cereals, breads, and crackers
  • Enjoy dark berries, especially cranberries, and naturally sweetened dark berry juices
  • Eat legumes regularly, especially soyfoods
  • Eat whole, unroasted nuts and seeds regularly, especially flaxseed
  • Limit your intake of dairy foods
  • Eat fresh vegetables every day
  • Eat at least one serving of mustard family vegetables (broccoli, cauliflower, kale, cabbage, and Brussels sprouts) daily
  • Explore the world of sea vegetables. It's a great time to become friends with sushi!
  • Have fresh fruit for dessert
  • Use olive oil instead of butter, margarine, or vegetable oils (olive oil consumption significantly lowers breast cancer risk)
  • Use spices every day, especially rosemary, ginger, turmeric, horseradish, basil, sage, thyme, oregano, saffron, paprika, and curry spice (these spices and others from their families seem to facilitate the metabolism of estrogen-like substances)
  • Eat garlic and onions regularly
  • Enjoy no more than one glass of wine daily, and preferably red wine

A five year study evaluating the dietary habits of nearly 9,000 women in northern Italy underscores the importance of healthy eating habits. This study, published in the April 2004 issue of Cancer Epidemiology, Biomarkers and Prevention identified four dietary patterns: salad vegetables (mainly consisting of raw vegetables and olive oil); western (mainly consisting of potatoes, red meat, eggs and butter); canteen (pasta and tomato sauce); and prudent (cooked vegetables, pulses, and fish, with negative loading on wines and spirits).

Only the women whose diet included lots of salad vegetables and olive oil had a reduced risk of breast cancer, and their reduction in risk was significant: 34-35%. Slender women (with a body mass index or BMI of <25) had an even greater 39% reduction in risk, whereas women whose BMI was > or =25 had no protective effect from consuming salad vegetables.

The take home message: you can help protect yourself against breast cancer. Just enjoy lots of fresh vegetables dressed with olive oil and maintain a healthy weight-a goal that happens naturally when following the George Mateljan Healthy Way of Eating.

If you're still worrying that cancer is inevitable or "in the genes," research published in the July 2004 issue of Cancer Epidemiology, Biomarkers & Prevention clearly shows that this is simply not the case. The everyday choices we make about the foods we eat can significantly reduce our cancer risk.

As Melanie Polk of the American Institute for Cancer Research said in a recent interview: "Every time we sit down to a meal we are presented with a fresh opportunity to bolster our bodies' natural defenses. The overwhelming majority of us routinely squander that opportunity."

Want to seize your chance to lower your risk not just of breast cancer but of all types of cancer?

The data published in Cancer Epidemiology, Biomarkers & Prevention from the Iowa Women's Health Study, in which 29,564 women were followed for 13 years, shows that those whose diet and lifestyle practices met American Institute for Cancer Research (AICR) guidelines had the lowest risk for all forms of cancer.

The AICR's 9 recommendations are:

  • Eat five or more servings of vegetables and fruits each day.
  • Eat 7 or more portions of complex carbohydrates such as whole grains and legumes each day, and restrict intake of processed foods and refined sugars.
  • Limit red meat to no more than 3 ounces daily.
  • Limit intake of fatty foods, particularly of animal origin.
  • Limit intake of salted foods and use of salt in cooking.
  • Limit alcoholic drinks to one (women) or two (men) daily.
  • Keep BMI (body mass index) under 25 and limit adult weight gain to no more than 11 pounds.
  • Engage in daily moderate and weekly vigorous physical activity.
  • Do not smoke.

Study data revealed that women who followed only one or none of AICR's diet and lifestyle recommendations had a 35% higher risk of developing cancer and a 43% higher risk of dying from cancer compared to women following most AICR recommendations.

Dr. James Cerhan, lead author of the study and head of the Mayo Clinic's Genetic Epidemiology and Risk Assessment Program, noted, "Furthermore, we estimate that if all the women in this study group had followed six or more of the guidelines and never smoked, approximately 30 percent of their new cancers and cancer deaths could have been prevented or delayed."

Our mission at the World's Healthiest Foods is to make it simple, practical, and easy for you enjoy the World's Healthiest Foods, and in doing so, you'll be following all the food-related AICR guidelines. If you haven't already, sign up for our Weekly Bulletin highlighting a different food at the peak of its season. Each week, you'll be inspired with new ideas and new recipes that meet AICR guidelines. We even send you a list of the groceries you'll need for the featured quick and easy recipe.

References
  • Adlercreutz H. Western diet and Western diseases: some hormonal and biochemical mechanisms and associations. Scand J Clin Lab Invest. 1990:50(S201):3-23 1990.
  • Adlercreutz H, Bannwart C, Wahala K, et al. Inhibition of human aromatase by mammalian lignans and isoflavonoid phytoestrogens. Steroid Biochem Molec Biol. 1993;44(2):147-153 1993.
  • Adlercreutz H, Hockerstedt K, Bannwart C, et al. Effect of dietary components, including lignans and phytoestrogens, on enterohepatic circulation and liver metabolism of estrogens and on sex hormone binding globulin (SHBG). J Steroid Biochem. 1987;27(4-6):1135-1144 1987.
  • Aggarwal B. Paper presented at the U.S. Defense Department's 'Era of Hope' Breast Cancer Research Program meeting in Philadelphia, PA, October 5, 2005,. reported in NUTRAingredients.com/Europe "Turmeric slows breast cancer spread in mice.".
  • Allred CD, Allred KF, Ju YH, Goeppinger TS, Doerge DR, Helferich WG. Soy processing influences growth of estrogen-dependent breast cancer tumors in mice. Carcinogenesis. 2004 May 6 [Epub ahead of print] 2004. PMID:15131010.
  • Basly JP, Marre-Fournier F, Le Bail JC, Habrioux G, Chulia AJ. Estrogenic/antiestrogenic and scavenging properties of (E)- and (Z)-resveratrol. Life Sci. 2000;66(9):769-777 2000.
  • Benincosa LJ, Sagawa K, Massey LK, Morris ME. Effects of acute caffeine ingestion and menopause on sulfate homeostasis in women. Life Sci. 1995;57(16):1497-1505 1995.
  • Bernard-Gallon DJ, Vissac-Sabatier C, Antoine-Vincent D et al. Differential effects of n-3 and n-6 polyunsaturated fatty acids on BRCA1 and BRCA2 gene expression in breast cell lines. Br J Nutr 2002 Apr;87(4):281-9 2002.
  • Bradlow HL, Davis DL, Lin G, Sepkovic D, Tiwari R. Effects of pesticides on the ratio of 16alpha/2-hydroxyestrone: a biological marker of breast cancer risk. Environ Health Perspect. 1995;103(Suppl 7):147-150 1995.
  • Brooks JD, Ward WE, Lewis JE, Hilditch J, Nickell L, Wong E, Thompson LU. Supplementation with flaxseed alters estrogen metabolism in postmenopausal women to a greater extent than does supplementation with an equal amount of soy. Am J Clin Nutr. 2004 Feb;79(2):318-25. 2004. PMID:14749240.
  • Cade JE, Burley VJ, Greenwood DC. Dietary fibre and risk of breast cancer in the UK Women's Cohort Study. Int J Epidemiol. 2007 Jan 24; [Epub ahead of print] 2007. PMID:17251246.
  • Cerhan JR, Potter JD, Gilmore JM, Janney CA, Kushi LH, Lazovich D, Anderson KE, Sellers TA, Folsom AR. Adherence to the AICR cancer prevention recommendations and subsequent morbidity and mortality in the Iowa Women's Health Study cohort. Cancer Epidemiol Biomarkers Prev. 2004 Jul;13(7):1114-20. 2004. PMID:15247121.
  • Cooney RV, Franke AA, Harwood PJ et al. Gamma-tocopherol detoxification of nitrogen dioxide:superiority to alpha-tocopherol. Proc Natl Acad Sci USA 1993 Mar 1;90(5):1771-5 1993.
  • Ericson U, Sonestedt E, Gullberg B, Olsson H, Wirfält E. High folate intake is associated with lower breast cancer incidence in postmenopausal women in the Malmo Diet and Cancer cohort. Am J Clin Nutr. 2007 Aug;86(2):434-43. 2007. PMID:17684216.
  • Eugster HP, Probst M, Wurgler FE, Sengstag C. Caffeine, estradiol, and progesterone interact with human CYP1A1 and CYP1A2. Evidence from cDNA-directed expression in Saccharomyces cerevisiae. Drug Metab Dispos. 1993;21(1):43-49 1993.
  • Fan S, Meng Q, Gao B, et al. Alcohol stimulates estrogen receptor signaling in human breast cancer cell lines. Cancer Res. 2000;60(20):5635-5639 2000.
  • Ferguson PJ, Kurowska E, Freeman DJ, Chambers AF, Koropatnick DJ. A flavonoid fraction from cranberry extract inhibits proliferation of human tumor cell lines. J Nutr. 2004 Jun;134(6):1529-35. 2004. PMID:15173424.
  • Fowke JH, Chung FL, Jin F, Qi D, Cai Q, Conaway C, Cheng JR, Shu XO, Gao YT, Zheng W. Urinary isothiocyanate levels, brassica, and human breast cancer. Cancer Res. Jul 15;63(14):3980-6. 2003. PMID:12873994.
  • Fowke JH, Longcope C, Hebert JR. Macronutrient intake and estrogen metabolism in healthy postmenopausal women. Breast Cancer Res Treat. 2001;65(1):1-10 2001.
  • Garcia-Segovia P, Sanchez-Villegas A, Doreste J, Santana F, Serra-Majem L. Olive oil consumption and risk of breast cancer in the Canary Islands: a population-based case-control study. Public Health Nutr 2006 Feb;9(1A):163-7. 2006. PMID:16512965.
  • Hirose K, Takezaki T, Hamajima N, Miura S, Tajima K. Dietary factors protective against breast cancer in Japanese premenopausal and postmenopausal women. Int J Cancer. 2003 Nov 1;107(2):276-82. 2003.
  • Hughes-Fulford M, Li CF, Boonyaratanakornkit J, Sayyah S. Arachidonic acid activates phosphatidylinositol 3-kinase signaling and induces gene expression in prostate cancer. Cancer Res. 2006 Feb 1;66(3):1427-33. 2006. PMID:16452198.
  • Jackson SJ, Singletary KW. Sulforaphane inhibits human mcf-7 mammary cancer cell mitotic progression and tubulin polymerization. J Nutr. 2004 Sep;134(9):2229-36. 2004. PMID:15333709.
  • Kern M, Tjaden Z, Ngiewih Y, Puppel N, Will F, Dietrich H, Pahlke G, Marko D. Inhibitors of the epidermal growth factor receptor in apple juice extract. Mol Nutr Food Res. 2005 Mar 9;49(4):317-328 [Epub ahead of print] 2005. PMID:15759309.
  • Kuriki K, Hirose K, Wakai K, Matsuo K, Ito H, Suzuki T, Hiraki A, Saito T, Iwata H, Tatematsu M, Tajima K. Breast cancer risk and erythrocyte compositions of n-3 highly unsaturated fatty acids in Japanese. Int J Cancer. 2007 Mar 12; [Epub ahead of print] 2007. PMID:17354239.
  • La Vecchia C, Negri E, Franceschi S, Decarli A, Lipworth L. Olive oil, other dietary fats, and the risk of breast cancer (Italy). Cancer Causes Control. 1995;6(6):545-550 1995.
  • Larsson SC, Giovannucci E, Wolk A. Dietary folate intake and incidence of ovarian cancer: the Swedish Mammography Cohort. J Natl Cancer Inst. 2004 Mar 3;96(5):396-402. 2004. PMID:14996861.
  • Liu RH, Liu J, Chen B. Apples prevent mammary tumors in rats. J Agric Food Chem. 2005 Mar 23;53(6):2341-3. 2005. PMID:15769178.
  • Maillard V, Bougnoux P, Ferrari P et al. N-3 and N-6 fatty acids in breast adipose tissue and relative risk of breast cancer in a case-control study in Tours, France. Int J Cancer 2002 Mar 1;98(1):78-83 2002.
  • Martin-Moreno JM, Willett WC, Gorgojo L, et al. Dietary fat, olive intake and breast cancer risk. Int J Cancer. 1994;58:774-780 1994.
  • Menendez JA, Vellon L, Colomer R, Lupu R. Oleic acid, the main monounsaturated fatty acid of olive oil, suppresses Her-2/neu (erbB-2) expression and synergistically enhances the growth inhibitory effects of trastuzumab (HerceptinTM) in breast. Ann Oncol. 2005 Jan 10; [Epub ahead of print] 2005. PMID:15642702.
  • Messina MJ, Persky V, Setchell KD, Barnes S. Soy intake and cancer risk: a review of the in vitro and in vivo data. Nutr Cancer. 1994;21:113-131 1994.
  • Offord EA, Mace K, Avanti O, Pfeifer AMA. Mechanisms involved in the chemoprotective effects of rosemary extract studied in human liver and bronchial cells. Cancer Lett. 1997;114:275-281 1997.
  • Parkin DM, Pisani P, Ferlay J. Estimates of the world wide incidence of eighteen major cancers in 1985. Int J Cancer. 1993;54:594-606 1993.
  • Pathak DR et al. Joint association of high cabbage/sauerkraut intake at 12-13 years of ago and adulthood with reduced breast cancer risk in Polish migrant women: results from the US component of the Polish women's he. Abstract number 3697. Presented at the AACR 4th Annual Conference on Frontiers in Cancer Prevention Research, October 30-November 2, 2005, Baltimore, Maryland. 2005.
  • Pierce JP, Stefanick ML, Flatt SW, Natarajan L, Sternfeld B, Madlensky L, Al-Delaimy WK, Thomson CA, Kealey S, Hajek R, Parker BA, Newman VA, Caan B, Rock CL. Greater survival after breast cancer in physically active women with high vegetable-fruit intake regardless of obesity. J Clin Oncol. 2007 Jun 10;25(17):2345-51. 2007. PMID:17557947.
  • Rose DP, Boyar AP, Wynder EL. International comparisons of mortality rates for cancer of the breast, ovary, prostate, and colon, and per capita food consumption. Cancer. 1986;58:2363-2371 1986.
  • Scambia G, Ranelletti FO, Benedetti Panici P, et al. Type-II estrogen binding sites in a lymphoblastoid cell line and growth-inhibitory effect of estrogen, anti-estrogen and bioflavonoids. Int J Cancer. 1990;46(6):1112-1116 1990.
  • Schwenke DC. Does lack of tocopherols and tocotrienols put women at increased risk of breast cancer. J Nutr Biochem 2002 Jan;13(1):2-20 2002.
  • Shannon J, Ray R, Wu C, Nelson Z, Gao DL, Li W, Hu W, Lampe J, Horner N, Satia J, Patterson R, Fitzgibbons D, Porter P, Thomas D. Food and botanical groupings and risk of breast cancer: a case-control study in Shanghai, China. Cancer Epidemiol Biomarkers Prev. 2005 Jan;14(1):81-90. 2005. PMID:15668480.
  • Shishodia S, Amin HM, Lai R, Aggarwal BB. Curcumin (diferuloylmethane) inhibits constitutive NF-kappaB activation, induces G1/S arrest, suppresses proliferation, and induces apoptosis in mantle cell lymphoma. Biochem Pharmacol. 2005 Sep 1;70(5):700-13. 2005. PMID:16023083.
  • Shrubsole MJ, Jin F, Dai Q, et al. Dietary folate intake and breast cancer risk: results from the Shanghai Breast Cancer Study. Cancer Res. 2001;61(19):7136-7141 2001.
  • Shultz TD, Howie BJ. In vitro binding of steroid hormones by natural and purified fibers. Nutr Cancer. 1986;8(2):141-147 1986.
  • Sieri S, Krogh V, Pala V, Muti P, Micheli A, Evangelista A, Tagliabue G, Berrino F. Dietary patterns and risk of breast cancer in the ORDET cohort. Cancer Epidemiol Biomarkers Prev. 2004 Apr;13(4):567-72. 2004. PMID:15066921.
  • Singletary K, MacDonald C, Wallig M. Inhibition by rosemary and carnosol of 7,12-dimethylbenz[a]anthracene (DMBA)-induced rat mammary tumorigenesis and in vivo DMBA-DNA adduct formation. Cancer Lett. 1996;104(1):43-48 1996.
  • Snedeker SM, Diaugustine RP. Hormonal and environmental factors affecting cell proliferation and neoplasia in the mammary gland. Prog Clin Biol Res. 1996;394:211-253 1996.
  • Steingraber S. Living Downstream. Reading, MA: Addison-Wesley Publishing Company, Inc.; 1997 1997.
  • Stoll BA. n-3 fatty acids and lipid peroxidation in breast cancer inhibition. Br J Nutr 2002 March;87(3):193-8 2002.
  • Stoll BA. Alcohol intake and late-stage promotion of breast cancer. Eur J Cancer. 1999;35(12):1653-1658 1999.
  • Sun J, Hai Liu R. Cranberry phytochemical extracts induce cell cycle arrest and apoptosis in human MCF-7 breast cancer cells. Cancer Lett. 2005 Dec 22; [Epub ahead of print] 2005. PMID:16377076.
  • Suzuki R, Rylander-Rudqvist T, Ye W, et al. Dietary fiber intake and risk of postmenopausal breast cancer defined by estrogen and progesterone receptor status--a prospective cohort study among Swedish women. Int J Cancer. 2008 Jan 15;122(2):403-12. 2008. PMID:17764112.
  • Trichopoulou A, Katsouyanni K, Stuver S, et al. Consumption of olive oil and specific food groups in relation to breast cancer risk in Greece. J Natl Cancer Inst. 1995;87:110-116 1995.
  • Verma SP, Goldin BR, Lin PS. The inhibition of the estrogenic effects of pesticides and environmental chemicals by curcumin and isoflavonoids. Environ Health Perspect. 1998;106(12):807-812 1998.
  • Whanger PD. China, a country with both selenium deficiency and toxicity: some thoughts and impressions. J Nutr 1989 Sep;119(9):1236-9 1989.
  • Wilson CL, Aboyade-Cole A, Darling-Reed S, Thomas RD. Poster Presentations, Session A, Abstract 2543: A30 Diallyl Sulfide Antagonizes PhIP Induced Alterations in the Expression of Phase I and Phase II Metabolizing Enzymes in Human Breast Epithelial Cells. presented at the American Association for Cancer Research's Frontiers in Cancer Prevention Research meeting in Baltimore, MD, July 2005. 2005.
  • Wood M. Citrus Compound, Ready to Help Your Body!. Agricultural Research, February 2005 2005.
  • Wu M, Harvey KA, Ruzmetov N, Welch ZR, Sech L, Jackson K, Stillwell W, Zaloga GP, Siddiqui RA. Omega-3 polyunsaturated fatty acids attenuate breast cancer growth through activation of a neutral sphingomyelinase-mediated pathway. Int J Cancer. 2005 Nov 10;117(3):340-8. 2005. PMID:15900589.
  • Yamamoto S, Sobue T, Kobayashi M, Sasaki S, Tsugane S. Soy, isoflavones, and breast cancer risk in Japan. J Natl Cancer Inst. 2003 Jun 18;95(12):906-13 2003.
  • Zand RS, Jenkins DJ, Diamandis EP. Steroid hormone activity of flavonoids and related compounds. Breast Cancer Res Treat. 2000;62(1):35-49 2000.
  • Zhang S, Hunter DU, Hankinson SE, et al. A prospective study of folate intake and the risk of breast cancer. JAMA. 1999;281(17):1632-1637 1999.
  • Zhang SM, Willett WC, Selhub J, Hunter DJ, Giovannucci EL, Holmes MD, Colditz GA, Hankinson SE. Plasma folate, vitamin B6, vitamin B12, homocysteine, and risk of breast cancer. J Natl Cancer Inst. 2003 Mar 5;95(5):373-80. 2003. PMID:12618502.
  • Zhu BT, Loder DP, Cai MX, Ho CT, Huang MT, Conney AH. Dietary administration of an extract from rosemary leaves enhances the liver microsomal metabolism of endogenous estrogens and decreases their uterotropic action in CD-1 mice. Carcinogenesis. 1998;19(10):1821-1827 1998.