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, the European Union banned the application/use of anabolic growth promoters in agriculture,” as well as the importation of American meat from animals injected with drugs like Zeranol, sold as “Ralgro Magnum.”
Zeranol, one of the most potent known endocrine disrupters, is 100,000 times more estrogenic than the plastics chemical, BPA, for example, and is the subject of my video Zeranol Use in Meat and Breast Cancer. “Zeranol constitutes a special case among potential endocrine disrupters, because Zeranol, in contrast to all other oestrogenic ‘endocrine disrupting’ chemicals, is present in human food because it is deliberately used in the production of consumer products. Furthermore, Zeranol is designed to be a potent, fairly persistent, [estrogen] whereas the [estrogenic] properties of the chemicals that are considered potential endocrine disrupters is accidental.”
If you drip blood from a cow implanted with the drug onto human breast cancer cells in a petri dish, you can double the cancer growth rate. We don’t drink blood, though, but preliminary data showed that muscle extracts—that is, 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 the human normal breast epithelial cell line” into breast cancer cells within 21 days.
“[O]bese individuals may be at greater risk of developing zeranol-induced breast cancer,” since they already have high levels of leptin, which is 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 Z[eranol] 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 the synthetic and the natural hormones, used as 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 this 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 that was marketed to 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 diethylstilbestrol (DES) and its use as a growth-promoting animal-feed additive, the United States finally banned its use in 1979 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 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, “[v]irtually the entire U.S. population consumes, without any warning, labeling, or information, unknown and unpredictable amounts of hormonal residues in meat products over a lifetime.” If all hormonal and other carcinogenic feed additives aren’t banned immediately, the least we should have is “explicit labeling requirements of use and of [hormone] residue levels in all meat products, including milk and eggs.”
Isn’t the DES story amazing? I had no idea it was used in meat production. Check out Illegal Drugs in Chicken Feathers for more on Big Pharma on Big Farms.
The most dangerous additive used in the meat industry is antibiotics, though. See, for example:
- Antibiotics: Agribusinesses’ Pound of Flesh
- MRSA Superbugs in Meat
- Drug Residues in Meat
- How Many Cancers Have Been Caused by Arsenic-Laced Chicken?
For more on what may be bad for the breast, check out:
- Breast Cancer and Alcohol: How Much Is Safe?
- Breast Cancer Risk: Red Wine v. White Wine
- Statin Cholesterol Drugs and Invasive Breast Cancer
- Cholesterol Feeds Breast Cancer Cells
- Cancer Risk from French Fries
- Estrogenic Cooked Meat Carcinogens
- Antiperspirants and Breast Cancer
- The Role of Bovine Leukemia Virus in Breast Cancer
And, for what may be protective, see:
- Broccoli vs. Breast Cancer Stem Cells
- Why Do Asian Women Have Less Breast Cancer?
- Flaxseeds and Breast Cancer Prevention
- Breast Cancer vs. Mushrooms
- Preventing Breast Cancer by Any Greens Necessary
- Tree Nuts or Peanuts for Breast Cancer Prevention?
- Fiber vs. Breast Cancer
- Which Dietary Factors Affect Breast Cancer Most?
- Should Women at High Risk for Breast Cancer Avoid Soy?
- How Not to Die from Cancer
Michael Greger, M.D.
Most of the attention on phthalates, a group of hormone-disrupting chemicals found in PVC plastics, has been focused on fetal and child health, particularly regarding genital and behavioral development. Recent data have shown, for example, “incomplete virilization in infant boys” and reduced masculine play as they grow up, and for girls, an earlier onset of puberty. What about affecting hormonal function in adults? I explore this in my video Avoiding Adult Exposure to Phthalates.
Men exposed to high levels of phthalate had lower testosterone levels, but that was for workers in a plastics plant. In the general population, the evidence is mixed. A study in Sweden of men in their 20s found no effect on testosterone, whereas a U.S. study on men in their 30s did find an effect, even at levels of exposure much lower than those of factory workers. When there’s conflicting evidence like this, ideally we’d put it to the test, but you can’t ethically expose people to phthalates so scientists have come up with convoluted methods like implanting the testicles from human fetuses into mice to keep them growing. We want to know about the effects on adult, not fetal, testicles, which had been harder to procure… until recently. “[C]onsent was obtained from all donors.” Now, I’ve heard of blood donors, but this is a whole other level. Researchers obtained donated testicles from prostate cancer patients who underwent castration to control their disease and, indeed, were able to get direct evidence that phthalates can inhibit testosterone production at the kinds of levels one sees in general population studies.
What about breast cancer, the number-one cancer killer of young women? Women working in automotive plastics and food canning are at five times the odds of breast cancer, suggesting a link. In a petri dish, however, phthalates didn’t seem to accelerate breast cancer growth at the levels of exposure expected in the general population. More recently, though, phthalate exposure was found to boost breast cancer cell growth in vitro at the levels found circulating in the bodies of many women. Therefore, the maximum tolerable dose set by governments should be re-evaluated.
How do you avoid the stuff? Well, when you think of plastic chemicals, you may think of water bottles, but they appear to play only a minor role. Most phthalates come from food. How do we know this? If you take people and have them stop eating for a few days, you get a significant drop in the amount of phthalates spilling into their urine. Fasting isn’t exactly sustainable, though. Thankfully, we can see similar drops from simply eating a plant-based diet for a few days, which gives us a clue as to where most phthalates are found. There were a few cases of spikes within the fasting period after showers, however, suggesting contamination in personal care products.
We can counsel patients to reduce phthalate exposures by avoiding the use of scented personal care products, soaps, and cosmetics, since phthalates are used as a fragrance carrier. Phthalates can also be found in children’s toys, as well as adult toys. “On behalf of the Danish [Environmental Protection Agency] EPA, [the Danish Technological Institute] DTI has made inquiries about the consumption pattern in connection with the use of sex toys made of rubber or plastics” to see what kind of exposure one might get “based on worst case scenarios.” Those working behind the counters at sex shops “proved to possess very little knowledge of the materials,” so the researchers had to do their own testing. It turns out that “jelly” is plasticized PVC—up to two-thirds phthalates by weight. Though the use of water-based lubricants may reduce the health risks 100-fold, phthalate exposure through lubricants may still have the opposite of the intended effect. Women with the highest levels of phthalates flowing through their bodies “had over 2.5 times the odds of reporting a lack of interest in sexual activity,” and these weren’t women in a canning factory, rather they were at typical exposure levels in America.
To find out how to lower your exposure to phthalates, see What Diet Best Lowers Phthalate Exposure?
More on hormone-disrupting chemicals in our food supply in:
- Chicken Consumption and the Feminization of Male Genitalia
- Zeranol Use in Meat and Breast Cancer
- Obesity-Causing Pollutants in Food
- Alkylphenol Endocrine Disruptors and Allergies
- Dietary Sources of Alkylphenol Endocrine Disruptors
- Dietary Pollutants May Affect Testosterone Levels
- How to Avoid the Obesity-Related Plastic Chemical BPA
- Why BPA Hasn’t Been Banned
- Are the BPA-Free Alternatives Safe?
- BPA Plastic and Male Sexual Dysfunction
Interested in learning more about improving sexual health? See:
- Survival of the Firmest: Erectile Dysfunction and Death
- 50 Shades of Greens
- Saffron for Erectile Dysfunction
- Best Food for Antidepressant-Induced Sexual Dysfunction
- Cholesterol and Female Sexual Dysfunction
- Best Foods to Improve Sexual Function
Michael Greger, M.D.
Atherosclerotic plaques may be more aptly described as pimples. These inflamed pockets of pus building up in the lining of our arteries can rupture, cut off our hearts’ blood supply, and kill us. In my 2-min. video Arterial Acne, I profile a New England Journal of Medicine review that describes the process.
Death from heart disease starts with cholesterol infiltrating the lining of the coronary arteries crowning our heart. This triggers an inflammatory response. The inner lining of our artery produces adhesion molecules to snag white blood cells, called monocytes, that zoom past in the blood stream to try to repair some of the havoc cholesterol had wreaked inside the artery wall. Other inflammatory cells are called into action, more pus builds up, and it can end up like a big whitehead sticking out into the blood flow inside the artery. The blood pulsating past can rip off the cap and clot off the entire width of the artery, which can result in a fatal heart attack.
The best way to stop this life-threatening cascade is to prevent it in the first place. As I describe in my 2-min. video Blocking the First Step of Heart Disease, we can block the buildup of cholesterol by increasing our intake of fiber-containing plant foods and decreasing our intake of trans fat, saturated fat, and cholesterol found in junk food and animal products.
Cholesterol-induced zits in the lining of our coronary arteries can also occur in other blood vessels. In our head they can cause a stroke (which I cover in my Uprooting video), in our back they can cause degenerative disk disease (Cholesterol and Lower Back Pain), in our abdomen they can cause an aneurysm (Abdominal Aortic Aneurysms: Ticking Time Balloons), and in our pelvis they can cause sexual dysfunction in both men (Atkins Diet: Trouble Keeping It Up) and women (Cholesterol and Female Sexual Dysfunction). Thankfully, Avoiding Cholesterol Is A No Brainer. It’s Purely a Question Of Diet. Trans fat, saturated fat, and cholesterol should be kept to a minimum.
What about blocking the inflammation stage that follows the buildup of cholesterol? Researchers at Arizona State studied the ability of various mushrooms to do just that. They took the lining of a human artery, soaked it overnight with either nothing—the control group—or shitake mushrooms, crimini mushrooms, oyster mushrooms, maitake mushrooms, or plain white button mushrooms. Which mushroom worked best to decrease the expression of adhesion molecules? As I show in my 2-min. video Making Our Arteries Less Sticky the answer is that plain white mushrooms worked the best! The cheapest, most convenient to find mushroom appeared to suppress inflammation the best.
For more magic from mushrooms, see Vegetables Versus Breast Cancer and Breast Cancer Prevention: Which Mushroom is Best? Just make sure to cook them (Toxins in Raw Mushrooms?). In terms of anti-inflammatory foods in general, check out Anti-Inflammatory Antioxidants, Garden Variety Anti-Inflammation, Aspirin Levels in Plant Foods, and Dried Apples Versus Cholesterol. In terms of pro-inflammatory foods, see the 4-part series Improving Mood Through Diet, Inflammatory Remarks About Arachidonic Acid, Chicken, Eggs, and Inflammation, and Chicken’s Fate is Sealed.
Some plants may be too anti-inflammatory to be used during pregnancy though. For the same reason aspirin should be avoided by pregnant women, chamomile may have such powerful anti-inflammatory properties that regular consumption may result in a serious fetal heart problem, premature constriction of the fetal ductus arteriosus (which allows the fetus to “breathe” in the womb). More in my recent 2-min. video Chamomile Tea May Not Be Safe During Pregnancy.
–Michael Greger, M.D.
Yesterday’s NutritionFacts.org video-of-the-day, Atkins Diet: Trouble Keeping It Up, discusses a case report of a man who went on a low carb diet, lost his ability to have an erection, and nearly lost his life. That was just one person, though. Researchers at Harvard recently looked at one hundred thousand people and concluded that low carb diets were “associated with higher all-cause mortality, higher cardiovascular disease mortality, and higher cancer mortality.” But what about the so-called “Eco-Atkins” diet? Find out in today’s video, Plant-Based Atkins Diet. And for more on erectile dysfunction as an early warning sign for heart disease, check out my video Rosy Glow.
Cholesterol builds up not only inside the arteries that feed our heart muscle, but inside all of our blood vessels. In the heart, atherosclerosis can cause a heart attack. In the brain, it can cause a stroke. In our legs, it can cause peripheral vascular disease and result in debilitating cramping; in our vertebral arteries, it can cause disc degeneration and lower back pain. And clogs in our pelvic arteries can lead to sexual dysfunction—and not just in men.
A landmark study published in the Journal of Sexual Medicine entitled “Hyperlipidemia and sexual function in premenopausal women” found that “Atherosclerosis of the arterial bed supplying female pelvic anatomy can lead to decreased vaginal engorgement and clitoral erectile insufficiency syndrome, similar to erectile problems in men, resulting in vasculogenic female sexual dysfunction,” an important factor of which may be “failure to achieve clitoral tumescence, or engorgement.” They found that women with high cholesterol reported significantly lower arousal, orgasm, lubrication, and satisfaction.
So as you plan for Valentine’s Day dinner, remember that eating healthier can extend not just one’s life, but also one’s love life.
-Michael Greger, M.D.
Motivating patients to change poor lifestyle habits can be extremely difficult. Preventing cardiovascular events such as heart attacks or strokes is a relatively distant benefit, whereas barbecued ribs, cheesecake, or sitting on our butts promises almost instant gratification. Public health experts are now hoping that prevention or improvement of erectile dysfunction could be a more immediate motivator that physicians can use to improve their patients’ lifestyles and in turn their overall cardiovascular health. That’s how doctors can save a life during a clinic visit for erectile dysfunction. (See Survival of the Firmest: Erectile Dysfunction and Death).
We used to think of erectile dysfunction in young men in their 20s and 30s as psychogenic in origin, meaning it’s all in their heads. But now we’re realizing it’s more likely an early sign of vascular disease. But even when the penis heads in the wrong direction, the heart need not follow. Atherosclerosis in both organs can be reversed with lifestyle changes. We know that “a substantial body of knowledge demonstrates that the abundant consumption of vegetables, fruit, and whole grain, and the dietary patterns rich in these foods, convey a markedly lower risk of coronary disease.” In a study profiled in my video, 50 Shades of Green, a group of researchers tried putting impotent men on a Mediterranean diet, which includes an abundance of plant-based foods. After two years on the Mediterranean diet, 37% of the men regained normal sexual function. What is it about the diet that appeared to do it? Improvements in erectile function were tied to five things: increased intake of fruits, vegetables, nuts, beans and essentially the ratio of plant fats to animal fats.
Similar benefits were found for women. The same kind of diet significantly improved sexual function, together with a significant reduction of systemic inflammation. As a whole, these findings “suggest that a Mediterranean-style diet may be a safe strategy for amelioration of sexual function” in women with pre-diabetes or diabetes, who found significant improvement in sexual satisfaction on the healthier diet. For more on preventing sexual dysfunction in women in the first place, see Cholesterol and Female Sexual Dysfunction. The improvement in sexual functioning is thought to be because of the anti-inflammatory and antioxidant benefits of plant-based diet.
Check out my related video: Pistachio Nuts for Erectile Dysfunction.
Other benefits of increased fiber intake may include improved bowel function (Bristol Stool Scale) and frequency (Prunes vs. Metamucil vs. Vegan Diet), lower colorectal cancer risk (Stool Size Matters), lower breast cancer risk (Relieving Yourself of Excess Estrogen and Fiber vs. Breast Cancer), lower blood pressure (Whole Grains May Work as Well as Drugs), lower blood cholesterol (How Fiber Lowers Cholesterol), weight loss (Beans and the Second Meal Effect) and a longer lifespan (What Women Should Eat to Live Longer).
A similar Mediterranean diet failed to help fibromyalgia in the short term (see Fibromyalgia vs. Mostly Raw & Mostly Vegetarian Diets), but diets that were even more plant-based were found to be beneficial: Fibromyalgia vs. Vegetarian & Raw Vegan Diets.
-Michael Greger, M.D.
According to the Centers for Disease Control and Prevention, the rates of all of our top 10 killers have fallen or stabilized except for one, suicide. As shown in my video, Antioxidants & Depression, accumulating evidence indicates that free radicals may play important roles in the development of various neuropsychiatric disorders including major depression, a common cause of suicide.
In a study of nearly 300,000 Canadians, for example, greater fruit and vegetable consumption was associated with lower odds of depression, psychological distress, self-reported mood and anxiety disorders, and poor perceived mental health. They conclude that since a healthy diet comprised of a high intake of fruits and vegetables is rich in anti-oxidants, it may consequently dampen the detrimental effects of oxidative stress on mental health.
But, that study was based on asking how many fruits and veggies people ate. Maybe people were just telling the researchers what they thought they wanted to hear. What if you actually measure the levels of carotenoid phytonutrients in people’s bloodstreams? The same relationship is found. Testing nearly 2000 people across the United States, researchers found that a higher total blood carotenoid level was indeed associated with a lower likelihood of elevated depressive symptoms, and there appeared to be a dose-response relationship, meaning the higher the levels, the better people felt.
Lycopene, the red pigment predominantly found in tomatoes (but also present in watermelon, pink grapefruit, guava and papaya) is the most powerful carotenoid antioxidant. In a test tube, it’s about 100 times more effective at quenching free radicals than a more familiar antioxidant like vitamin E.
Do people who eat more tomatoes have less depression, then? Apparently so. A study of about a thousand older men and women found that those who ate the most tomato products had only about half the odds of depression. The researchers conclude that a tomato-rich diet may have a beneficial effect on the prevention of depressive symptoms.
Higher consumption of fruits and vegetables has been found to lead to a lower risk of developing depression, but if it’s the antioxidants, can’t we just take an antioxidant pill? No.
Only food sources of antioxidants were protectively associated with depression. Not antioxidants from dietary supplements. Although plant foods and food-derived phytochemicals have been associated with health benefits, antioxidants from dietary supplements appear to be less beneficial and may, in fact, be detrimental to health. This may indicate that the form and delivery of the antioxidants are important. Alternatively, the observed associations may be due not to antioxidants but rather to other dietary factors, such as folate, that also occur in plant-rich diets.
In a study of thousands of middle-aged office workers, eating lots of processed food was found to be a risk factor for at least mild to moderate depression five years later, whereas a whole food pattern was found to be protective. Yes, it could be because of the high content of antioxidants in fruits and vegetables but could also be the folate in greens and beans, as some studies have suggested an increased risk of depression in folks who may not have been eating enough.
Low folate levels in the blood are associated with depression, but since most of the early studies were cross-sectional, meaning a snapshot in time, we didn’t know if the low folate led to depression or the depression led to low folate. Maybe when you have the blues you don’t want to eat the greens.
But since then, a number of cohort studies were published, following people over time. They show that a low dietary intake of folate may indeed be a risk factor for severe depression, as much as a threefold higher risk. Note this is for dietary folate intake, not folic acid supplements; those with higher levels were actually eating healthy foods. If you give people folic acid pills they don’t seem to work. This may be because folate is found in dark green leafy vegetables like spinach, whereas folic acid is the oxidized synthetic compound used in food fortification and dietary supplements because it’s more shelf-stable. It may have different effects on the body as I previously explored in Can Folic Acid Be Harmful?
These kinds of findings point to the importance of antioxidant food sources rather than dietary supplements. But there was an interesting study giving people high dose vitamin C. In contrast to the placebo group, those given vitamin C experienced a decrease in depression scores and also greater FSI. What is FSI? Frequency of Sexual Intercourse.
Evidently, high dose vitamin C improves mood and intercourse frequency, but only in sexual partners that don’t live with one another. In the placebo group, those not living together had sex about once a week, and those living together a little higher, once every five days, with no big change on vitamin C. But for those not living together, on vitamin C? Every other day! The differential effect for non-cohabitants suggests that the mechanism is not a peripheral one, meaning outside the brain, but a central one—some psychological change which motivates the person to venture forth to have intercourse. The mild antidepressant effect they found was unrelated to cohabitation or frequency; so, it does not appear that the depression scores improved just because of the improved FSI.
For more mental health video, see:
- Aspartame and the Brain
- Exercise vs. Drugs for Depression
- Do Antidepressant Drugs Really Work?
- Fighting the Blues with Greens?
- Gut Feelings: Probiotics and Mental Health
- Saffron vs. Prozac
Anything else we can do to enhance our sexual health and attractiveness? See:
- Eating Better to Look Better
- Cholesterol and Female Sexual Dysfunction
- Survival of the Firmest: Erectile Dysfunction and Death
- 50 Shades of Greens
- Dietary Pollutants Affect Testosterone Levels
Michael Greger, M.D.