Is Soy Healthy for Breast Cancer Survivors?

Soyfoods have become controversial in recent years,…even among health professionals,…exacerbated by misinformation found on the Internet.” Chief among the misconceptions is that soy foods promote breast cancer, because they contain a class of  phytoestrogen compounds called isoflavones. Since estrogens can promote breast cancer growth, it’s natural to assume phytoestrogens might too.

But, people don’t realize there are two types of estrogen receptors in the body—alpha and beta. And, unlike actual estrogen, soy phytoestrogens “preferentially bind to and activate [estrogen receptor beta]. This distinction is important, because the 2 [types of receptors] have different tissue distributions…and often function differently, and sometimes in opposite ways.” And, this appears to be the case in the breast, where beta activation has an anti-estrogenic effect, inhibiting the growth-promoting effects of actual estrogen—something we’ve known for more than ten years. There’s no excuse anymore.

The effects of estradiol, the primary human estrogen, on breast cells are completely opposite to those of soy phytoestrogens, which have antiproliferative effects on breast cancer cells, even at the low concentrations one gets in one’s bloodstream eating just a few servings of soy—which makes sense, given that after eating a cup of soybeans, the levels in our blood cause significant beta receptor activation.

So, where did this outdated notion that soy could increase breast cancer risk come from? The concern was “based largely on research that showed that [the main soy phytoestrogen] genistein stimulates the growth of mammary tumors in [a type of] mouse.” But, it turns out, we’re not actually mice. We metabolize soy isoflavones very differently from rodents. The same soy leads to 20 to 150 times higher levels in the bloodstream of rodents. The breast cancer mouse in question was 58 times higher. So, if you ate 58 cups of soybeans a day, you could get some significant alpha activation, too. But, thankfully, we’re not hairless athymic ovariectomized mice, and we don’t tend to eat 58 cups of soybeans a day.

At just a few servings of soy a day, with the excess beta activation, we would assume soy would actively help prevent breast cancer. And, indeed, “[s]oy intake during childhood, adolescence, and adult life were each associated with a decreased risk of breast cancer.” Those women who ate the most soy in their youth appear to grow up to have less than half the risk.

This may help explain why breast cancer rates are so much higher here than in Asia—yet, when Asians come over to the U.S. to start eating and living like Americans, their risk shoots right up.  For example, women in Connecticut—way at the top of the breast cancer risk heap—in their fifties have, like, ten times more breast cancer than women in their fifties living in Japan. But, it’s not just genetic, since when they move here, their breast cancer rates go up generation after generation, as they assimilate into our culture.

Are the anti-estrogenic effects of soy foods enough to actually change the course of the disease? We didn’t know, until the first human study on soy food intake and breast cancer survival was published in 2009 in the Journal of the American Medical Association, suggesting that “[a]mong women with breast cancer, soy food consumption was significantly associated with decreased risk of death and [breast cancer] recurrence.” Followed by another study, and then another, all with similar findings.

That was enough for the American Cancer Society, who brought together a wide range of cancer experts to offer nutrition guidelines for cancer survivors, to conclude that, if anything, soy foods should be beneficial. Since then, two additional studies have been published, for a total of five, and they all point in the same direction. Five out of five, tracking more than 10,000 breast cancer patients.

Pooling all the results, soy food intake after breast cancer diagnosis was associated with reduced mortality (meaning a longer lifespan) and reduced recurrence—so, less likely the cancer comes back. Anyone who says otherwise hasn’t cracked a journal open in seven years.

And, this improved survival was for both women with estrogen receptor negative tumors and estrogen receptor positive tumors, and for both younger women, and for older women. Pass the edamame.

Doctor’s Note

This is probably the same reason flax seeds are so protective. See Flax Seeds & Breast Cancer Survival: Epidemiological Evidence and Flax Seeds & Breast Cancer Survival: Clinical Evidence.

What about women who carry breast cancer genes? I touched on that in BRCA Breast Cancer Genes & Soy, and it’s the topic of my next video, Should Women at High Risk for Breast Cancer Avoid Soy?

What about genetically modified soy? I made a video abut that too; see GMO Soy & Breast Cancer.

Who Shouldn’t Eat Soy? Glad you asked. Watch that video too! 🙂

Not all phytoestrogens may be protective, though. See The Most Potent Phytoestrogen is in Beer and What are the Effects of the Hops Phytoestrogen in Beer?

If you haven’t yet, you can subscribe to my videos for free by clicking here.

In health,
Michael Greger, M.D.

Michael Greger, M.D., is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous “meat defamation” trial. Currently Dr. Greger proudly serves as the Director of Public Health and Animal Agriculture at the Humane Society of the United

Acupuncture After Breast Cancer Treatment

According to the latest study conducted by the researchers at the Perelman School of Medicine at the University of Pennsylvania, acupuncture is considered a feasible option for women complaining of hot flashes following treatment with estrogen-targeting therapies for breast cancer.

acupuncture-breast-cancer-hot-flashes

According to researchers, acupuncture can be effective on women who had breast cancer treatments and they are experiencing hot flashes.

In the survivors of breast cancer, hot flashes are severe and seen frequently, but the measures approved by FDA  for the treatment of these episodes such as hormone replacement therapy are not suitable for the survivors of breast cancer due to the presence of estrogen. The study results are published in the Journal of Clinical Oncology.

Jun J. Mao, MD, MSCE, an associate professor in the department of community health and family medicine, said that the majority of people relate hot flashes with menopause, this episode may also appear in women surviving breast cancer who are having low levels of estrogen and  usually undergo premature menopause  after being treated with surgery or chemotherapy.

The results of the latest research clearly highlight the promising role acupuncture in the control of hot flashes in breast cancer survivors, which was also proven effective for joint pain in the same population in previous studies.

In general, hot flushes are the transient episodes of flushing, racing heartbeat, sweating and heat sensations. The actual cause of hot flashes is not known though they are closely linked with decreased levels of estrogen.

Study details

The team of researchers have enrolled a total of 120 breast cancer survivors experiencing multiple episodes of hot flashes in a day. The participants were then distributed randomly into four different interventions to check the efficacy of acupuncture technique known as electro acupuncture (embedded needles delivering weak electrical currents) compared to an epilepsy drug gabapentin in reducing the incidence of hot flushes. The participants were given the following treatments for the period of 8 weeks:

  • gabapentin (900 mg) daily
  • gabapentin placebo daily,
  • electro acupuncture twice a week for  two weeks then once weekly
  • “sham” electro acupuncture (involves  no needle penetration or electric current)

After a period of 8 weeks, it was found that participants in the electroacupuncture group have maximum improvement in the standard measurement severity and frequency of hot flashes also known as the Hot flash composite score(HFCS).

Along with the reduction in frequency and severity of hot flushes, both the groups of acupuncture also showed lesser side effects than the pill groups.

The Penn researchers have followed these subjects for another sixteen weeks after the end of the treatment and have observed that both the acupuncture groups enjoyed a lasting and better control over hot flashes, and the pill-placebo groups showed only minimal improvement in the symptoms, Whereas worsening in the hot flashes was observed in the group taking gabapentin.

Evidence from the previous studies suggests that acupuncture works by directly enhancing the levels of endorphins and their associated pain killing and mood elevating molecules.

This article briefly describes the role of acupuncture in controlling hot flashes. You can get details by following the given link.
Source: Acupuncture reduces hot flashes in breast cancer survivors, September 3, 2015

Dr. Adem GunesDr. Adem Gunes has built the world’s largest database of scientifically tested natural substances with proven effects in cancer treatments. In 2009, he was appointed as the Chief Physician of ProLife Clinic in Innsbruck, Austria, and played a key role in the establishment of the research laboratory. He is also the co-founder of the first Austrian hyperthermia center. Now, Dr. Adem works closely with cancer patients from around the world (including Germany, Thailand, Dubai) to recommend them a complementary cancer clinic or to create a personalized care plan for patients to follow at home.

Why are women at a higher risk of leukemia after breast cancer treatment?

leukemia after breast cancer treatmentResearchers have been trying to determine ways to prevent the complications in the breast cancer survivors to reduce the occurrence of a relapse. The breast cancer treatments that include radiation therapy and chemotherapy target the malignant cells in the breast tissues and destroy them.

However, these treatments also affect the healthy cells, which results in an increase in the risk of leukemia in the future, the researchers said. They are conducting studies to determine the factors that may cause an increased risk of leukemia after breast cancer treatment.

The possible factors that are believed to contribute to the risk of secondary malignancy are the family history of cancer and an inherited gene mutation.

The research involved a follow-up of 88 breast cancer survivors who were treated for breast cancer and developed leukemia at a later stage. It was found that the women had a family history of cancer, which suggested a genetic susceptibility to develop cancer like leukemia.

About 20 percent of the women in this study group had an inherited gene mutation, which can increase the risk of breast cancer.

“This is expected to enable the scientists in determining how these genes affect or modify the breast cancer treatment-related leukemia risk. It will also help to understand whether any specific treatment causes a higher risk based on the inherited genetic make-up of a woman,” said Dr. Jane Churpek, the study leader from the University of Chicago.

This will help the oncologists to have a patient-specific conversation about the potential risks of radiation and chemotherapy treatments for breast cancer.

It may be difficult to determine the exact role of breast cancer treatment in the development of leukemia. Hence, it is important that the breast cancer patients are uniquely positioned so that the true frequency and the causative factors of subsequent leukemia can be ascertained.

American Society of Clinical Oncology and the American Cancer Society have issued guidelines for improving the survival rates of breast cancer patients. The breast cancer survivors are advised to undergo routine physical exams and mammograms to check for any new tumor.  They do not need additional lab tests or imaging unless there are significant symptoms suggesting that a malignancy may have returned.

The guidelines include recommendations in five key areas, which include:

  • Regular surveillance for the recurrence of malignancy by physical examination and the patient’s cancer history
  • Regular mammographic screening
  • Management and assessment of the psychosocial and long-term physical impact of breast cancer treatment
  • Care coordination and practical implications
  • Promotion of a healthy lifestyle

With regular follow-up and monitoring, the occurrence of complications following breast cancer treatment is expected to decline. This will increase the life expectancy of breast cancer survivors and also improve their quality of life.

References:
1. Leukemia Risk After Breast Cancer Treatment
2. ASCO and ACS Issue Guideline on Breast Cancer Survivor Care
3. Organizations issue joint guidelines for breast cancer survivors

Featured Photo: HealthyWomen.org

Dr. Adem GunesDr. Adem Gunes has built the world’s largest database of scientifically tested natural substances with proven effects in cancer treatments. In 2009, he was appointed as the Chief Physician of ProLife Clinic in Innsbruck, Austria, and played a key role in the establishment of the research laboratory. He is also the co-founder of the first Austrian hyperthermia center. Now, Dr. Adem works closely with cancer patients from around the world (including Germany, Thailand, Dubai) to recommend them a complementary cancer clinic or to create a personalized care plan for patients to follow at home.

 

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