Lavender for Generalized Anxiety Disorder

Lavender oil, distilled from lavender flowers, is “most often used in aromatherapy and massage. Despite its popularity…only recently [have] scientifically-based investigations [been undertaken] into its biological activity,” however. There have been “small-scale studies” suggesting benefit from lavender massage; but, maybe it’s the massage, not the lavender.

There was a study on patients in intensive care, comparing massage with odorless oil to lavender oil, and though patients massaged with lavender oil did say they “felt less anxious and more positive,” there were no objective differences found in terms of blood pressure, breathing, or heart rate. Frankly, maybe the lavender was just covering up the nasty hospital smells.

Subsequent studies using more sensitive tests did find physiological changes, though. We know, for example, the smell of lavender changes brain wave patterns. But, what effect does this have? Well, evidently it makes people feel better, perform math better (faster and more accurately), whereas the smell of rosemary, for example, seemed to enable folks only to do math faster—not necessarily with greater accuracy.

What if you actually eat lavender flowers, or, in this case, take capsules of lavender-infused oil, so you could double-blind the study to compare lavender head-to-head to a drug like Valium (lorazepam, known as Ativan), for generalized anxiety disorder.

Generalized and persistent anxiety is a frequent problem, and is treated with benzodiazepines—benzos or downers, like Valium. “Unfortunately, these substances” can not only make you feel like you have a hangover, but “have a high potential for drug abuse” and addiction.

So, they decided to give lavender a try. The drug Ativan certainly reduces anxiety, but, so does lavender. By the end, you couldn’t tell which was which. And, in fact, among those that responded to either, the lavender actually seemed to work better.

“Since lavender oil has no potential for drug abuse and causes no hangover effects [it] appears to be an effective and well-tolerated alternative to benzodiazepine [drugs] for [the] amelioration of generalised anxiety.”

Cautionary Note

There was a case series published in the New England Journal of Medicine. “Prepuberty Gynecomastia Linked to Lavender.” Reports of young boys exposed to lavender-containing lotions, soaps, hair gel, and shampoo starting to develop breasts, which disappeared after these products were discontinued—suggesting that lavender oil may possess hormone-disrupting activity.

And, indeed, when dripped on estrogen receptor-positive human breast cancer cells, lavender does show estrogenic effects, and a decline in male hormone activity, though it’s unknown if similar reactions occur inside the body when lavender flowers or lavender oil is ingested.

Doctor’s Note

The math thing is so cool! How else might one use natural means to improve cognitive performance? Check out Does a Drink Of Water Make Children Smarter? For more mind-body brain hacking tips, see Dietary Brain Wave Alteration.

More on dietary interventions for anxiety in:

In fact, the saffron may be aromatherapeutic too. See my follow-up to the PMS study, Wake Up & Smell the Saffron. And, speaking of brain effects, see Saffron vs. Prozac, Saffron for the Treatment of Alzheimer’s, and Saffron vs. Aricept.

For more flower power, see my blog post, Hibiscus tea: flower power. Also check out my videos, on hibiscus tea (Better than Green Tea?) and chamomile tea (Red Tea, Honeybush, & Chamomile and Chamomile Tea May Not Be Safe During Pregnancy). And hey, broccoli florets are just clusters of flower buds. See The Best DetoxBroccoli vs. Breast Cancer Stem Cells, and dozens of my other videos on broccoli.

How else might diet affect with the hormonal balance of young boys? Check out Dairy & Sexual Precocity.

More on lavender in my next video Lavender for Migraine Headaches.

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

In health,
Michael Greger, M.D.

Dr. Michael Greger on Breast Cancer Authority Blog

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

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How Meat Stimulates Breast Cancer

In 1979, an epidemic of breast enlargement was noted in Italian children. Poultry or veal was suspected, given that estrogens may be fed to farm animals to accelerate their weight gain. After this episode, Europe banned the use of anabolic growth promoters in agriculture, and has banned the importation of American meat from animals injected with drugs like Zeranol, sold as Ralgro Magnum.

Zeranol is the one of the most potent known endocrine disruptors—100,000 times more estrogenic than the plastics chemical, BPA, for example. And Zeranol constitutes a special case among potential endocrine disruptors, because in contrast to all other estrogenic “endocrine-disrupting” chemicals, Zeranol is present in human food, because it’s deliberately used—in fact, designed to be a potent, persistent, estrogen, whereas the estrogenic properties of the other chemicals are accidental.

And if you drip blood from a cow that’s been implanted with the drug on human breast cancer cells in a petri dish, you can double the cancer growth rate. We don’t drink blood, though, but preliminary data also showed that muscle extracts, meat extracts, also stimulated breast cancer cell proliferation.

Furthermore, Zeranol may cause the transformation of normal breast cells into cancer cells in the first place. Zeranol-containing blood from implanted cattle was capable of transforming normal human breast cells into breast cancer cells within 21 days.

Obese women may be at greater risk of developing Zeranol-induced breast cancer, since they already have high levels of leptin, a hormone produced by fat cells, that can itself promote breast cancer growth. And Zeranol exposure can greatly enhance this growth-promoting action. This result also suggests that Zeranol may be more harmful to obese breast cancer patients than to normal weight breast cancer patients, in terms of breast cancer development.

In conclusion, because these anabolic growth promoters in meat production are, by far, the most potent hormones found in human food, we should really be testing people, especially children, before and after eating this meat. It amazes me that it hasn’t been done, and until it has, we have no idea what kind of threat they may pose—though the fact that Zeranol is as potent as estradiol—the primary sex steroid in women and DES—should concern us. DES is another synthetic estrogen marketed to pregnant women—all pregnant women until 1971, when it was shown to cause vaginal cancers in the daughters. But few know it was also used in meat.

In the absence of effective federal regulation, the meat industry uses hundreds of animal feed additives, with little or no concern about the carcinogenic and other toxic effects of dietary residues of these additives. Illustratively, after decades of misleading assurances of the safety of DES and its use as a growth-promoting animal feed additive, the United States finally banned its use some 40 years after it was first shown to be carcinogenic. The meat industry then promptly switched to other potentially carcinogenic additives, such as Zeranol.

When girls started dying from vaginal cancer, DES-treated meat was subsequently banned in Europe. However, misleading assurances, including the deliberate suppression of residue data, managed to delay a U.S. ban on DES in the meat supply for eight years.

Today, virtually the entire U.S. population consumes, without any warning, labeling, or information, unknown and unpredictable amounts of hormone residues in meat products over a lifetime. If all hormonal and other carcinogenic feed additives aren’t banned immediately, the least we could have is “explicit labeling requirements of the use and of [hormone] residue levels in all meat products, including milk and eggs.”

Doctor’s Note

Isn’t that amazing about the DES story? I had no idea it was used in meat production. Check out some of the other Big Pharma on Big Farms: Illegal Drugs in Chicken Feathers.

The most dangerous additive used in the meat industry is antibiotics, though. See, for example:

For more on what may be bad for the breast, check out:

And for what may be protective, see:

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

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

How to Block Breast Cancer’s Estrogen-Producing Enzymes

The vast majority of breast cancers start out “hormone-dependent,” meaning the primary human estrogen, called “estradiol plays a crucial role in [breast cancer] development and progression.” That’s one of the reasons why soy food consumption appears so protective against breast cancer—because soy phytoestrogens, like genistein, act as estrogen-blockers. They block the binding of estrogens, like estradiol, to breast cancer cells.

But, wait a second. “The majority of breast cancers occur [after menopause], when the ovaries have [stopped producing estrogen].” What’s the point of eating estrogen blockers if there’s no estrogen to block? It turns out the breast cancer tumors themselves produce their own estrogen from scratch to fuel their own growth.

Estrogens may be formed in breast tumors by multiple pathways. The breast cancer takes cholesterol, and, using the aromatase enzyme, or two hydroxysteroid dehydrogenase enzymes, produces its own estrogen.

So, there’s two ways to stop breast cancer. One is to use “antiestrogens,” estrogen-blockers, like the soy phytoestrogens, or “the anti-estrogen [drug] tamoxifen…However, another way to block estradiol is by using anti-enzymes” to prevent the breast cancer from making all the estrogen in the first place.

And, indeed, there are a variety of anti-aromatase drugs in current use. In fact, inhibiting the estrogen production has been shown to be “more effective” than just trying to block the effects of the estrogen—”suggesting that the inhibition of estrogen synthesis is clinically very important for the treatment of estrogen-dependent breast cancer.” It turns out soy phytoestrogens can do both.

Using ovary cells taken from women undergoing in vitro fertilization, soy phytoestrogens were found to reduce the expression of the aromatase enzyme. What about in breast cancer cells, though? Breast cancer cells, too—not only suppressing aromatase activity, but the other estrogen-producing enzyme, too.

But, this is in a petri dish. Does soy suppress estrogen production in people too Well, circulating estrogen levels appear significantly lower in Japanese women than American white women. And, Japan does have the highest per capita soy food consumption. But, you don’t know it’s the soy until you put it to the test. Japanese women were randomized to add soymilk to their diet—or not—for a few months. Estrogen levels did seem to drop about a quarter in the soymilk-supplemented group. Interestingly, when they tried the same experiment in men, they got similar results: a significant drop in female hormone levels, with no change in testosterone levels.

These results, though, are in Japanese men and women that were already consuming soy in their baseline diet. So, it’s really just looking at “higher versus lower…soy intake.”

What happens if you give soymilk to women in Texas? Circulating estrogen levels cut in half. Since increased estrogen levels are a “[marker] for high risk for breast cancer,” the effectiveness of soy to reduce estrogen levels may help explain why Chinese and Japanese women have such low rates of breast cancer.

And, what was truly remarkable is that estrogen levels stayed down a month or two, even after they stopped drinking it. This suggests you don’t have to consume soy every day to have the cancer-protective benefit.

Doctor’s Note

Wait, soy protects against breast cancer? Yes, in study after study after study. Even in women at high risk? See BRCA Breast Cancer Genes & Soy.

Even if you already have breast cancer? See Is Soy Healthy for Breast Cancer Survivors?

Even GMO soy? See GMO Soy & Breast Cancer.

Okay, then, Who Shouldn’t Eat Soy? Watch that video too! 🙂

What else can we do to decrease breast cancer risk? See:

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

Antiperspirants and Breast Cancer

A famous case report, called “The Mortician’s Mystery,” in the New England Journal of Medicine back in the 80s, described a man whose testicles started shrinking and breasts started growing. Turns out, he failed to wear gloves as he massaged embalming cream onto his corpse. They conclude there must have been some estrogenic compound in the cream that got absorbed through his skin into his body—one of the first such cases described.

This case was cited as inspiration by a group of researchers that came up with a new theory to explain a breast cancer mystery. Why do most breast cancers occur in the upper outer corner of the breast? The standard explanation was simply because that’s where most of the breast tissue is located, as the so-called tail of the breast extends up into the armpit.

But, that doesn’t explain this. It didn’t always used to be this way; there’s been a shift towards that upper corner. And, it doesn’t explain this: “greater genomic instability”—chromosome abnormalities that may signal precancerous changes. There definitely seems to be something happening to that side of the breast, and something relatively new—just in the last 50 years or so.

“Is it possible that the increasing use of [underarm] antiperspirant which parallels increasing breast cancer incidence could…be an explanation for [the] greater number of…tumours…,…and [the] disproportionate incidence of breast cancer in the upper outer quadrant” of the breast near where the stick, spray, or roll-on is applied?

There’s a free flow of lymph fluid back and forth between the breast and the armpit. And, if you measure aluminum levels in breasts removed after mastectomies, “[t]he aluminum content of breast tissue in the outer regions [near the armpits] was significantly higher”—presumably due to “closer proximity” to the underarm region.

This is a concern, because, in a petri dish at least, “it has been demonstrated that aluminum is a [so-called] metalloestrogen,” having pro-estrogenic effects on breast cancer cells. “Long-term exposure” of normal breast tissue cells in a test tube to aluminum concentrations “in the range of those” found in the breast results in precancerous-type changes. And then, once the cells have turned, those same concentrations can “increase the migratory and invasive activity” of human breast cancer cells in a petri dish.

This is important, because women don’t die from the tumor in the breast itself, “but from the ability of the cancer cells to spread and grow at distant sites,” like the bones, lungs, liver, or brain. But, we don’t care about petri dishes; we care about people.

In 2002, a paper was published in the Journal of the National Cancer Institute, in which the underarm antiperspirant habits of 800 breast cancer survivors [were] compared to those of women who never got breast cancer. The first study of its kind, and they found “no indication” of a link between the two.

Based on this study, Harvard Women’s Health Watch assured women that antiperspirants do not cause breast cancer. “Women who are worried that antiperspirants might cause breast cancer can finally rest easy.”

But, two months later, this study. “Frequency and early onset of antiperspirant/deodorant usage with underarm shaving was associated with an earlier age of breast cancer diagnosis”—as much as 20 years earlier—in women using antiperspirant, and shaving their armpits more than three times a week. And, the earlier they started, before vs. after their sweet 16, appeared to move up their breast cancer 10 or 20 years. They conclude that “underarm shaving with antiperspirant…use, may play a role in breast cancer” after all.

But what does shaving have to do with it? Shaving removes more than just armpit hair; it removes armpit skin. You end up shaving off the top skin layer. And, while there’s very little aluminum absorption through intact skin, when you strip off that outer layer with a razor, and then rub on an antiperspirant, you get a six-fold increase in aluminum absorption through the skin. So, good news for women who don’t shave, but “[o]n the other hand, [the] high [through-the-skin aluminum] uptake on [shaved] skin should compel antiperspirant manufacturers to proceed with the utmost caution.”

European safety authorities and the FDA specifically advise against using aluminum antiperspirants on damaged or “broken skin.” Yet, shaving before antiperspirant application “can create abrasions in the skin.” I’m sure everyone knows about the FDA warning, having read title 21 part 350 subpart C50-5c1 of the Code of Federal Regulations.

But, we get so much aluminum in our diet from processed foods—”anti-caking agents [in like] pancake mix,…melting agents in [American] cheese,…meat binders,…gravy…thickeners,…baking powder,” candy—that the contribution from underarm antiperspirants would presumably be minimal in comparison.

“But everything was turned topsy-turvy in 2004,” when a case was reported of “a woman with bone pain and fatigue” suffering from aluminum toxicity. But, within months of stopping the antiperspirant, which she was applying daily to her regularly-shaved pits, her aluminum levels came down, and “her symptoms” resolved. Although not everyone sucks up that much aluminum, the case “suggests that caution should be exercised when using aluminum-containing antiperspirants frequently.”

Recently, it was shown that women with breast cancer have twice the level of aluminum in their breasts, compared to women without breast cancer—though this doesn’t prove cause and effect. Maybe the aluminum contributed to the cancer, or maybe the cancer contributed to the aluminum. Maybe tumors just suck up more aluminum? Subsequent research suggests this alternative explanation is unlikely. So, where do we stand now?

The latest review on the subject concluded that as a consequence of the new data, given that aluminum can be toxic, and we have no need for the stuff, “reducing the concentration of this metal in antiperspirants is a matter of urgency.” Or, at the very least, it should say on the label: Do not use after shaving. Or, we could cease usage of aluminum-containing antiperspirants altogether.

But then, won’t we stink? Ironically, antiperspirants can make us stink worse. They increase the types of bacteria that cause body odor. It’s like the story with antidepressant drugs—how they can actually make you more depressed in the long run. The more we use antiperspirants, the more we may need them. Awfully convenient for a billion-dollar industry.

Doctor’s Note

Whoa—lots in the that video! Normally I’d try to break that video up, but I really wanted all the information to be in one place. Please consider sharing with those in your life who may benefit.

Any way to decrease BO through changes in diet? I’ve got an ancient video on that (see Body Odor & Diet), with some new updated ones coming down the pike!

Here’s the antidepressant video I referenced: Do Antidepressant Drugs Really Work?

What else can we do to decrease breast cancer risk? See, for example:

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

How Much Soy Should You Eat To Lower Breast Cancer Risk?

So, we know 7 to 18 servings of soy a day may neutralize some of the beneficial effects of avoiding animal protein. At the same time, studies have repeatedly found that women who eat lots of soy appear to have a lower risk of getting breast cancer, and a better risk of surviving breast cancer than those who don’t eat soy. So is there some magic number of soy food servings we should shoot for?

So far we know that somewhere between 7 and 18 may not be so good, so more than 18 definitely gets the axe. This two year study found no effect on IGF levels of adding two servings of soy foods daily, whether they were tofu, soy milk, soy nuts, or the concentrated soy isolate found in plant-based meats, protein bars, or protein powder; still fine.

Still got a big range here. This study suggested 5 to 10 servings a day was bad— increased IGF—so we’re kind of slowly but surely narrowing down the safety window. Same year in Japan; three servings a day cleared the IGF radar. And then, that’s it. That’s all the science we have so far.

The bottom line is that legumes should be a part of everyone’s daily diet, which means lentils, peas, and/or beans, ideally with each of our meals—of which soy is an excellent choice. But, I recommend that we should probably stick to no more than 3 to 5 servings a day.

Doctor’s Notes

This is the fourth in a string of videos on the role plant and animal proteins play in determining levels of the cancer-promoting growth hormone IGF-1. Also see IGF-1 as One-Stop Cancer ShopProtein Intake and IGF-1 ProductionHigher Quality May Mean Higher RiskAnimalistic Plant Proteins; and Too Much Soy May Neutralize Benefits. For the role soy plays in extending breast cancer survival, see Breast Cancer Survival and Soy. And, I’ve got dozens of other videos on soy.

For further context, be sure to check out my associated blog posts: How Much Soy Is Too Much? and Why Less Breast Cancer in Asia?

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

BRCA Breast Cancer Genes & Soy Consumption Research Results

Why do people who eat legumes—beans, chickpeas, split peas, and lentils—live longer? Well, men and women who eat legumes tended towards being lighter, having a slimmer waist, lower blood sugars, lower cholesterol, lower triglycerides, better kidney function, lower blood pressure, and so—no surprise—may live longer. But, interestingly, bean intake was “a better protectant against mortality in women than men.” They think this may be because cancer was the leading killer of women in this population—especially breast cancer. And, we know that breast cancer survivors who eat soy foods, for example, have a significantly lower likelihood of the cancer recurrence. Eating soy foods appears to protect against the cancer coming back. This 2012 review looked at three prospective human studies done to date, and found that women who ate the most soy had a 29% lower risk of dying from breast cancer, and a 36% lower risk of cancer recurrence. And, a fourth study was since published, and it showed the same thing. “[S]oy food intake is associated with longer survival and lower recurrence among breast cancer patients. With an average intake of soy phytonutrients above 17 milligrams a day, which is about what’s found in a single cup of soy milk, the mortality of breast cancer may be able to be reduced by as much as 38%.

Here’s the survival curve over five years. The purple line represents the survival of the women with the highest soy consumption. As you can see, after two years, all the breast cancer survivors eating lots of soy were still alive. But, a quarter to a third of the women who ate the least soy were dead. And, after five years, 90% of the tofu-lovers were still alive and kicking, whereas half of the tofu-haters kicked the bucket. And, you can see a similar relationship when you look at breast cancer survival and soy protein intake, as opposed to soy phytonutrient intake.

How does soy so dramatically decrease cancer risk, and improve survival? Soy may actually help turn back on BRCA genes. BRCA is a so-called caretaker gene, an oncosuppressor—meaning a cancer-suppressing gene responsible for DNA repair. Mutations in this gene can cause a rare form of hereditary breast cancer, popularized by Angelina Jolie’s public decision to undergo a preventive double mastectomy.

But, only about 5% of breast cancers run in families. So, 95% of breast cancer victims have fully functional BRCA genes. So, if their DNA-repair mechanisms are intact, how did breast cancer form, grow, and spread? Well, tumors do it by suppressing the expression of the gene, through a process called methylation. The gene’s fine, but cancer found a way to turn it off, or at least turn it down—potentially facilitating the metastatic spread of the tumor.

And, that’s where soy may come in. Maybe the reason soy intake is associated with increased survival and decreased cancer recurrence is because the phytonutrients in soy turn back on your BRCA protection—removing the methyl straightjacket the tumor tried to place on it.

So, researchers put it to the test. These are three different types of human breast cancer, specially stained so that the expression of BRCA genes turns up brown. So, this is what full DNA repair would look like—hopefully, what normal breast cells would look like. Lots of brown, lots of BRCA expression. But, instead, we have column two, raging breast cancer.

Well, if you add soy phytonutrients back to the cancer, BRCA does indeed get turned back on. The DNA repair appears to start ramping back up—though this was at a pretty hefty dose, equivalent to about a cup of soybeans.

Their results suggest that treatment with soy phytonutrients “might reverse DNA hypermethylation, and restore the expression” of the tumor-suppressor genes BRCA1 and BRCA2. May help with other breast cancer genes, as well. “Women at increased [genetic] risk of breast cancer may especially benefit from high [soy] intake.”

Doctor’s Notes

Legumes leading to a longer life? See Increased Lifespan from Beans.

No matter what genes we inherit, changes in diet can affect DNA expression at a genetic level. For example, see:

I’ve previously covered the available science in Breast Cancer Survival & Soy. Other effects are detailed in:

It may be possible to overdo beans, though (see How Much Soy Is Too Much?).

For further context, check out my associated blog posts: Top 10 Most Popular Videos of 2013 and Can Eating Soy Prevent Breast Cancer?

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

Can Green Tea Help Prevent Cancer?

Tea consumption is associated with a reduced risk of [heart disease], stroke,” and premature death in general, with each additional cup of green tea a day associated with a 4% lower mortality risk. So, maybe, “drinking several cups of tea daily can keep the doctor away”—as well as the mortician. But, what about cancer?

“There is growing evidence from laboratory, [population], and human intervention[al] studies that tea can exert beneficial disease-preventive effects,” and further, may actually “slow cancer progression.” Let’s review some of that evidence.

Not only do those who drink a lot of tea appear to live years longer than those who drink less; drinking lots of tea may delay the onset of cancer. Now, these are in Japanese tea cups, which only contain half a cup; so, the highest category here is greater than or equal to five full cups of tea, not ten. The women that did get cancer appeared to get it seven years later if they had been drinking lots of tea compared to those who consumed less, whereas men had a three-year delay, the difference male versus female due, potentially, to their smoking habits.

Green tea may be able to interfere with each of the stages of cancer formation: the initiation of the first cancer cell, promotion into a tumor, and then, the subsequent progression and spread. Cancer is often initiated when a free radical oxidizes our DNA, causing a mutation. But within 40 minutes of drinking green tea, you can get a nice “spike” in the antioxidant power of your bloodstream. “This increase…, in turn, [may] lower oxidative damage to DNA and so decrease [the] risk of cancer.”

Furthermore, in terms of “genoprotective effects”—protecting our genes—”pre-existing oxidation-induced DNA damage was…lower” after drinking green tea, suggesting that it can boost DNA repair as well. But, we didn’t know for sure, until now.

There’s a DNA-repair enzyme in our body called OGG1, and within one hour of drinking a single cup of green tea, we can boost its activity—though after a week of tea drinking, we can boost it even higher. So, “regular intake of green tea [may have] additional benefits in the prevention and/or repair of DNA damage.” Tea is so DNA-protective, it can be used for sperm storage for fresh samples until they can be properly refrigerated.

And so anti-inflammatory, it can be used for pain control as a mouthwash after wisdom tooth surgery. And, in terms of controlling cancer growth, at a dose of green tea compounds that would make it into someone’s organs after drinking six cups of tea, it can cause cancer cells to commit suicide—apoptosis (programmed cell death)—while leaving normal cells alone.

There’s lots of chemo agents that can kill cancer through brute force. But, that can make normal cells vulnerable too. So, “green tea appears to be potentially an ideal agent” for cancer prevention: “little or no adverse side effects,” efficacious for multiple cancers “at achievable dose levels,” and can be taken orally.

We have a sense of how it works: by stopping cancer cells from growing and causing them to off themselves. It’s cheap and has a history of safe, acceptable use. But this was all based on in vitro studies in a test tube. It needs to be evaluated in human trials: give people with cancer green tea to see if it helps—which we’ll explore, next.

Doctor’s Note

Sorry about the cliffhanger! I just wanted to offer a good backgrounder on the antioxidant and anti-inflammatory activities. Stay tuned for Can Green Tea Help Treat Cancer?

You don’t have to wait for info on prostate cancer, though. See my recent videos: Preventing Prostate Cancer with Green Tea and Treating Prostate Cancer with Green Tea.

I also have a few older videos:

That wisdom tooth thing is so interesting. It can also just be used as an anticavity mouth rinse (see What’s the Best Mouthwash?).

Is Caffeinated Tea Dehydrating? Watch the video!

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

Should Women at High Risk for Breast Cancer Avoid Soy?

Five studies have been performed on breast cancer survival and soy foods, involving more than 10,000 breast cancer patients. And, those who eat more soy live longer, and have a lower risk of the cancer coming back. But, what about women who carry breast cancer genes? Fewer than 10% of breast cancer cases run in families. But, when they do, it’s most likely mutations to one of the tumor suppressor genes—BRCA1 or BRCA2—that defend the integrity of our genes. They are involved in DNA repair, and so, if either one of them is damaged, or has mutations, chromosomal abnormalities can result, which can set us up for cancer.

This idea that we have tumor suppressor genes goes back to famous research in the 60s that showed that if you fuse together a normal cell with a cancer cell, the cancer cell doesn’t turn the normal cell malignant. Rather, the normal cell suppresses the cancerous one. Tumor suppressor genes are typically split up into two types. There are gatekeeper genes that keep cancer cells in check, and caretaker genes that keep the cell from going cancerous in the first place. And, BRCA genes appear able to do both—that’s why their function is so important.

breast-cancer-and-soy-concernsUntil recently, dietary recommendations for those with mutations focused on reducing DNA damage caused by free radicals, by eating lots of antioxidant-packed fruits and vegetables. If your DNA-repair capacity is low, you want to be extra careful about damaging your DNA in the first place. But, what if we could also boost BRCA function?

In my last video on the topic, I showed how, in vitro, soy phytoestrogens could turn back on BRCA protection suppressed by breast cancer, upregulating BRCA expression as much as 1,000% within 48 hours. But, does that translate out of the petri dish and into the person? Apparently so.

Soy intake was only associated with 27% breast cancer risk reduction in people with normal BRCA genes, but a 73% risk reduction in carriers of BRCA gene mutations. So, a healthy diet may be particularly important in those at high genetic risk. Meat consumption, for example, was linked to twice as much risk in those with BRCA mutations—97% increased risk, instead of just 41% increased risk of breast cancer in those with normal BRCA genes.

Doctor’s Note

What about for women without breast cancer genes, or for women who have already been diagnosed? That was the subject of my last video, Is Soy Healthy for Breast Cancer Survivors?. The older video I referred to is BRCA Breast Cancer Genes & Soy.

What is in meat that may increase risk? See, for example:

Featured Image From Authority Nutrition and Livestrong.

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

Is Soy Healthy for Breast Cancer Survivors?

is-soy-healthy-for-breast-cancer-survivorsSoyfoods 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?

In health,

Michael Greger, M.D.

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

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