Why Did Doctors Keep Prescribing Cancer?

We’ve known about the role of estrogen in breast cancer going back to the 1800s, when surgical removal of the ovaries seemed to help in some cases. Ovaries were said to send out “mysterious” influences to the rest of the body, which were identified as estrogen in 1923. The medical profession jumped on this discovery and started injecting menopausal women by the thousands, and it was said that “[t]he ‘shot’ gives a ‘respectable’ hook on which to hang the visit to the doctor…” Soon, there were pills and patches, and medical journals like the Journal of the American Medical Association regaled doctors with ads I feature in my video How Did Doctors Not Know About the Risks of Hormone Therapy? on how they can “help the women to happiness by simply prescribing estrogen” and, “[w]hen women outlive their ovaries…,” there is Premarin.

As far back as the 1940s, concerns were raised that this practice might cause breast cancer, noting it would have been nice to figure this out before we started dosing women en masse. But breast cancer risk didn’t seem to matter as much, because heart disease was the number-one killer of women, reviews concluded, and because women taking hormones appeared to have lower heart attack rates, which would outweigh any additional breast cancer. However, women taking estrogen tended to be of a higher socioeconomic class, exercised more, and engaged in other healthy lifestyle changes like consuming more dietary fiber and getting their cholesterol checked. So, maybe that’s why women taking estrogen appeared to be protected from heart disease. Perhaps it had nothing to do with the drugs themselves. Despite the medical profession’s “enthusiasm for estrogen replacement therapy,” only a randomized clinical trial could really resolve this question. We would need to divide women into two groups, with half getting the hormones and half getting a placebo, and follow them out for a few years. There was no such study…until the 1990s, when the Women’s Health Initiative study was designed.

Wait a second. Why did it take the bulk of a century to decide to definitively study the safety of something prescribed to millions of women? Perhaps because there had never been a female director of the National Institutes of Health until then. “Just three weeks after being named NIH Director in 1991, [Bernadine Healy] went before Congress to announce, ‘We need a moon walk for women.’ That ‘moon walk’ took the form of the Women’s Health Initiative, the most definitive, far-reaching clinical trial of women’s health ever undertaken in the United States.”

The bombshell landed in summer 2002. There was so much more invasive breast cancer in the hormone users that they were forced to stop the study prematurely. What about heart disease? Wasn’t that supposed to balance things out? The women didn’t just have more breast cancer—they had more heart attacks, more strokes, and more blood clots to their lungs.

The news that women treated with hormone replacement therapy “experienced higher rates of breast cancer, cardiovascular disease, and overall harm has rocked women and physicians across the country.” Estrogen started out as the most prescribed drug in America before the study, but, after, the number of prescriptions dropped immediately and, within a year, so did the incidence of breast cancer in the United States.

The most important question about this story is why were we all so surprised? There had been “decades of repeated warnings” about the risks of cancer. In fact, the reason breast cancer patients had so much trouble suing the pharmaceutical company was that “the drugs have contained warning labels for decades.” And, with that disclosure, surely any reasonable physician would have included it in their risk and benefit discussions with their patients, right? It’s like the warning labels on packs of cigarettes. If you get lung cancer now, you should have known better. And, so, if you were on hormone replacement therapy and got breast cancer, don’t blame the drug company. They warned you about the risks, right there in the fine print.

Why didn’t more doctors warn their patients? Even after the study came out, millions of prescriptions continued to be dispensed. That’s a lot of cancer in our patients we caused, wrote one doctor. “How long will it take us to discard the financial gains, to admit that we are harming many of our patients, and to start changing our prescription habits?”

“Why did this practice continue in the face of mounting evidence of harm?” Well, it is a multibillion-dollar industry. “Despite an overwhelming amount of evidence to the contrary, many physicians still believe that estrogenic hormones have overall health benefits,” a “non-evidence-based perception [that] may be the result of decades of carefully orchestrated corporate influence on medical literature.” Indeed, “[d]ozens of ghostwritten reviews and commentaries published in medical journals and supplements were used to promote unproven benefits and downplay harms of menopausal hormone therapy…” PR companies were paid to write the articles that were then passed off as having been written by some expert.

What now? “Gynecologists must switch allegiance from eminence-based to evidence-based medicine.” In other words, they must consider what the science says and not just what some so-called expert says. It’s been said that the “current culture of gynecology encourages the dissemination of health advice based on advertising rather than science.”

“Women were placed in the way of harm by their physicians, who acted as unsuspecting patsies for the pharmaceutical companies.” If we really wanted to prevent heart attacks in women, simple lifestyle behaviors can eliminate more than 90 percent of heart attack risk. So, instead of being Big Pharma’s pawns, “recommending a healthful diet, increased exercise, and smoking cessation would truly benefit women’s health.”


The whole Premarin debacle speaks to the importance of putting purported therapies to the test (see, for example, Do Vitamin D Supplements Help with Diabetes, Weight Loss, and Blood Pressure?), as well as to the power of Big Pharma (Eliminating Conflicts of Interest in Medical Research), medical community collusion (American Medical Association Complicity with Big Tobacco), and my most series on mammograms.

What about Plant-Based Bioidentical Hormones and Soy Phytoestrogens for Menopause Hot Flashes? Check out the videos to find out.

In general, patients (and doctors) tend to wildly overestimate the efficacy of pills and procedures. See Why Prevention Is Worth a Ton of Cure and The Actual Benefit of Diet vs. Drugs.

Medical care, in general, may be the third leading cause of death in the United States. See How Doctors Responded to Being Named a Leading Killer.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Pomegranates Put to the Test for Prostate Cancer

The pomegranate “has been revered through the ages for its medicinal properties”––so much so that it’s been used as a symbol for some medical organizations. A fruit seems to me a better representation of health than the American Medical Association’s snake on a stick.

The pomegranate is thought to be beneficial for a wide range of diseases, including several types of cancer, cardiovascular disease, and rheumatoid arthritis. Evidently even the cannibals love it as it improves the color of “kid meat.” The researchers were talking about baby goats, but the title of their study did make me do a double-take!

Most of the attention over the last decade has focused on pomegranates and prostate cancer. In vitro studies have shown that pomegranate extract can suppress the growth of prostate cancer cells in a petri dish by up to 95 percent. As you can see in my video Pomegranate vs. Placebo for Prostate Cancer, there is no real difference between what normal prostate cells look like under a microscope with a little or a lot of pomegranate extract; it doesn’t seem to have much of an effect on healthy cells. However, prostate cancer cells are decimated by pomegranate extract—at least in a petri dish, but what about in a person? If these results translated to the clinic, it could be dramatic, but we first need to try it out in people.

“Primary management of prostate cancer…consists of either radical surgery or radiation therapy.” Despite this, “a significant number of patients relapse and ultimately develop metastatic disease.” Even after radical prostatectomy, the cancer comes back in about one-third of the patients, as evidenced by rising prostate-specific antigen (PSA) levels. At that point, the treatment options are limited as the prostate has already been removed. The next step is essentially chemical castration, or hormonal ablation. Just like breast cancer can thrive on estrogen, prostate cancer can thrive on testosterone. We can try to wipe out testosterone, but that can have such negative side effects that anything we can do to delay that would be good. 

So, what about plants? Men in Asia appear to have the lowest prostate cancer rates in the world, up to ten times lower than men in North America. Is this simply because of genetics? No. When Japanese individuals move to the United States and start living and eating like us, their breast and prostate cancer rates shoot right up toward ours. It could be because of what they start eating more of: animal products, which are the strongest risk factor for prostate cancer worldwide on a country-by-country basis. Or, it could be because of what they’re eating less of in the United States, namely their traditional low-fat, high-fiber, generally plant-rich diet with soy products and green tea. So, did the researchers put the cancer patients on a plant-based diet? No, they just had them drink a cup of pomegranate juice every day. Why? Because the study was funded by a pomegranate juice company.

In the three years leading up to the study, participants’ cancer was steadily growing, as measured by the increase in their average PSA levels. Once they started the juice, their tumors continued to grow, but it looked like they were growing slower. In contrast, Dean Ornish and his colleagues got an apparent reversal in early prostate cancer growth with a plant-based diet and other healthy lifestyle changes. Indeed, PSA didn’t just go up slower—it trended down. And, when dripping the blood of the men on prostate cancer cells growing in a lab, the blood serum of those eating healthfully suppressed cancer growth nearly eight times better, whereas the blood of the men on the pomegranate juice suppressed cancer growth by only about 12 percent. Still, to see any effect from drinking a cup of juice a day is pretty impressive.

The problem is that there was no control group in the pomegranate juice study. We could say the patients acted as their own controls, before and after. It’s probably not just a coincidence that their tumors started growing slower right when they started the juice. But, a drug trial tried to do the same thing—treat men with recurring prostate cancer after surgery or radiation. In the drug group, tumor growth slowed in 55 percent of the men. A pretty effective drug, right? Well, the sugar pill worked 73 percent of the time. The placebo effect can be so powerful that it may slow cancer growth. This is why we need placebo-controlled trials. Maybe tricking people into drinking pomegranate-flavored Kool-Aid would have had the same effect. We don’t know until we put it to the test.

Finally, researchers did a randomized, controlled trial of pomegranate juice for prostate cancer, and the daily pomegranate intake had no impact. What do they mean, no impact? Twenty-five percent of the cancer patients appeared to shrink their tumors as soon as they started drinking the pomegranate juice, but 35 percent shrunk their tumors not drinking pomegranate juice. So, any effect appears just to be a placebo. It’s the same story with pomegranate extract pills: They seemed to work until they went head to head with sugar pills and fell flat on their face.


I love pomegranates! Unfortunately, the juice and extracts look no more promising today than when I produced my video Is Pomegranate Juice That Wonderful?.

For some foods that may actually affect prostate cancer progression, see:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Meat Can Cause Stress Hormone Levels to Rise and Testosterone levels to Drop

A critique of the scientific validity of the dietary advice in Men’s Health magazine discovered nuggets claiming meat can give men “a testosterone boost,” but we’ve known for a quarter century that a meal with that much fat can drop testosterone levels by nearly one-third within hours. In fact, a significant drop of both free and bound testosterone in the bloodstream occurs within just one hour of it going in one’s mouth, whereas a low-fat meal of mostly carbs has no such effect. Based on in vitro studies on the effects of fat on testicle cells in a petri dish, researchers suspect fat in the blood may actually suppress testosterone production in real time. If you feed people lots of eggs and meat, including fish and poultry, and then switch them to a diet with bread, fruit, vegetables, and sugar—but about the same amount of fat—all their testosterone levels go up. Even more importantly, however, all their levels of cortisol, a stress hormone produced by our adrenal glands, go down.

Having low stress hormone levels is good, because high cortisol levels may “strongly predict cardiovascular death” in men and women both with and without pre-existing cardiovascular disease. In fact, this may help explain “death from a broken heart,” the heightened heart attack and stroke risk in the immediate weeks following the loss of a spouse. Higher cortisol levels days, months, or even years after losing someone you love may increase cardiac risk and reduce immune function. And, the rise in stress hormone levels from the loss of a spouse, a bump of about 50 points, is less than the bump you get by eating high-meat diet.

Cortisol may also help explain why those who are depressed tend to put on abdominal fat. The reason obesity around the middle is associated with elevated cortisol secretion may be that abdominal fat kind of sucks it up, so the accumulation of fat around our internal organs may be an adaptation by which our body deals with excess stress.

These spikes in stress hormone levels every time we eat a lot of meat may not just affect our health, but that of our children, which I discuss in my video Maternal Diet May Affect Stress Responses in Children. “Substantial evidence now suggests that maternal diets of high protein density have adverse effects on the fetus.” For example, back in the 1960s, an experiment was performed on pregnant women in Motherwell, Scotland, in which they were told to eat a high-meat diet in hopes of preventing preeclampsia, a disease of pregnancy. It didn’t work. In fact, the lowest preeclampsia rates I’ve ever seen were among women eating strictly plant-based diets—only 1 case out of 775 pregnancies. Preeclampsia normally strikes about 5 percent of pregnancies, so there should have been dozens of cases, suggesting a plant-based diet could alleviate most, if not all, of the signs and symptoms of this potentially serious condition. So what did happen when pregnant women went from eating about one daily portion of meat to about two portions a day? Mothers who ate more meat and fewer vegetables during pregnancy gave birth to children who grew up to have higher blood pressures.

“One explanation proposed for the adverse effects of high-meat/fish consumption is that this may increase maternal cortisol concentrations, which, in turn, affect the developing fetus,” resetting his or her stress hormone thermostat to a higher level. But, we don’t know until we put it to the test. And indeed, researchers found higher blood cortisol levels “in both the sons and daughters of women who had reported higher meat/fish” consumption, about a 5 percent increase for every meat serving per day. Such diets may present a metabolic stress to the mother and kind of reprogram the adrenal axis of their children, leading to lifelong hypercortisolemia, elevated levels of stress hormones in the blood. This may help explain why every daily portion of meat during late pregnancy may lead to a 1 percent greater fat mass in their children by the time they reach adolescence. So, this could increase the risk of their children becoming obese later in life and thus has “important implications for public health and in terms of prevention of obesity.”

What if they’re already born? We may be able to bring down children’s stress hormone levels with similar dietary changes, but this is just baseline stress hormone levels. Do children of mothers who eat more meat during pregnancy also have exaggerated responses to life stressors? Researchers put them through a stressful challenge—public speaking and mental arithmetic—and then measured their cortisol responses. If their mom ate less than two servings of meat/fish a day while she was carrying them, they got little shots of stress hormones from their adrenal glands. Those whose moms ate more really got stressed out, and those whose moms ate the most—17 or more servings a week, which is more than 2 servings each day—appeared to be really quaking in their boots. In a way, you are what your mother ate.


Want more craziness from Men’s Health magazine? Check out my video Changing a Man’s Diet After a Prostate Cancer Diagnosis.

Here are some other popular videos about eating healthfully during pregnancy:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations: