Naked Truth: Xenoestrogens

An interview with Dr. John K. Williams

The strength coaches, trainers, scientists, nutritionists, and editors at T-Nation have been debunking nutrition, supplementation, and fitness myths for years now with topics ranging from glutamine use to training frequency to tuna fish & mercury.

Recently, I was lucky enough to sit down and speak with Dr. John K. Williams about the controversial and myth-riddled topic of xenoestrogens (synthetic chemicals that act similar to estrogen).

For those of you who aren't familiar with Dr. Williams, let me briefly walk you through his circum vitae. Dr. John Williams initially received a B.S. in anthropology and psychology from Southwest Missouri State University. He then went on to earn his PhD in anthropology, specializing in old world archaeology from Southern Methodist University in Dallas Texas (where he then served on the faculty).

John has always had a strong interest in nutrition, specifically Paleolithic nutrition; a topic in which he has researched, written, and lectured on extensively. He co-authored Gourmet Nutritionwith Dr. John Berardi and can now be heard weekly as the co-host of the FitCast Podcast.

Testosterone: John, thanks for taking the time to sit down and talk with me today. Tell me, how did an archeologist get interested in xenoestrogens?

John Williams: Well, as you can tell from my background I have rather diverse interests. Archaeology is a subfield of anthropology, and back when I was a professor, I used to cover all the subfields in the general courses that I taught. One of the subfields that I covered was medical anthropology. Since I was already interested in nutrition, fitness, and lifting weights, my interest in xenoestrogens was a little self-serving. But basically I didn't want to screw up my hard earned gains in the gym with any sort of environmental estrogens.

I wanted to introduce the students to this as well. So to start the discussion of xenoestrogens in class I would show a documentary by the BBC called the Estrogen Effect. The video basically makes you say "Oh my god I'm swimming in a sea of estrogens and I'm doomed to live the life of a hermaphrodite."

It's a very reactionary film that probably goes overboard on several issues, but it puts the idea of what xenoestrogens are in your head and the potential dangers of them to you and the environment. A lot of time folks just don't know about these dangers.

T: Okay great. Let's step back a bit for the people who aren't familiar with the topic. What exactly are xenoestrogens?

JW: Xenoestrogens are man-made chemicals that can enter the body and mimic the effects of the female hormone estrogen.

Natural estrogens act with a larger molecule called a receptor, and once they do so, the biological activity associated with that hormone is turned on. You're basically flipping on a switch. Xenoestrogens fit in the same receptors that estrogen does and do the same thing that the natural hormone does. But in addition they can also turn-on more receptors – sometimes synergistically – making the effect of the estrogen or xenoestrogen more profound.

The readers of Testosterone Nation certainly know that large amounts of estrogen are not exactly desirable for people wanting to be lean and muscular.

T: Yeah that's not exactly what we're looking for. So are xenoestrogens related to phytoestrogens in any way?

JW: No, they can act the same, but phytoestrogens occur naturally in plant foods and xenoextrogens are these man made monstrosities. In my opinion, there's nothing to be worried about with phytoestrogens, unless you're consuming them in an extremely isolated form and in great abundance. I certainly don't agree with how the popular media has touted phytoestrogens, and soy in particular, as panaceas.

I'd rather not have a bunch of phytoestrogens floating around in my body, making me want to sit down for a viewing of "Must Love Dogs" with a tray of cupcakes. On the other hand, I don't think that they pose the same health risks as xenoestrogens do. To me the real threat are the xenoestrogens.

Probably the most important difference between the two is that xenoestrogens accumulate in the adipose tissue of humans and animals, while phytoestrogens are metabolized and spend relatively little time in the body.

T: What are the origins of xenoestrogens? How and when people were first introduced to them? Since they are chemicals I'm guessing that someone had to synthesize them at one point.

JW: Right, well it goes way back. British scientists synthesized the first xenoestrogen in 1938. It was known as diethylstilbestrol, or DES for short. I'll be throwing around a lot of acronyms today so I apologize if it confuses the readers. DES was considered a wonder drug and was immediately given to women experiencing problems during pregnancy in the belief that insufficient estrogen levels caused miscarriages and premature births.

It is true that insufficient estrogen levels can cause miscarriages during the first three months of pregnancy, but it was naïve to start pumping women full of synthetic hormones with little regard for side effects. So it was prescribed to all pregnancies as if it were a vitamin or miracle pill that could improve on nature. Over five million women in the United States, Europe, and Latin America received DES treatment.

Coincidentally, that same year (1938), in Switzerland, a researcher discovered dichlorodiphenyl trichloroethane (DDT) and found that it worked great as an insecticide. DDT is also a xenoestrogen, and was widely adopted in agriculture and public health programs. It wasn't evil by any means because it saved millions of people's lives when it proved to be the most effective agent known at wiping out diseases transmitted by insects, such as malaria.

T: John, since you mentioned DDT and malaria. I wanted to bring this up. Steven Milloy of Fox News and is adamantly against the ban on DDT because of these positive effects on malaria. What's you opinion on this? Do the benefits really out weigh the risks?

JW: Basically, Steve Milloy sees himself as a warrior fighting mistruths spread by evil scientists. But if you look at what he debunks, his real criteria for deciding what is "junk science" is not the quality of the work but the political agenda that it might support. has this death clock attributing almost 92 million deaths to the EPA's ban on DDT since 1972. If you look at this ban in closer detail, what he's trying to do is actually pretty misleading. The fact is that there is not a ban on using DDT to fight malaria. The EPA only banned DDT from agricultural use, but it can still be used for disease prevention.

He's fighting a strawman. For example following the tragic tsunami in 2003, Milloy and others of like mind were calling for the spraying of DDT, yet what he didn't say is that the mosquitoes in that area have evolved to have a resistance to DDT. It doesn't work in that area.

The debate goes on and on, with the Milloy camp claiming that, even if Sri Lankan mosquitoes have developed a resistance to DDT, it is still useful for keeping mosquitoes out of houses when the walls are coated with this insecticide. That reasoning doesn't work, however, because India has been using DDT continuously since the 1940's, yet rates of malaria continue to rise.

The death clock is completely bogus. Stephen Milloy may look like he is talking big, but in reality he's just spreading the same mistruths he claims to be debunking.

T: John that's great stuff. It looks like we've debunked a submyth here. Okay so let's get back on track. You were just talking about the inception of the xenoestrogen DDT and how it was used as an insecticide. What happened after that?

JW: Well, folks in the mid 20th century started noticing the bad effects of these xenoestrogens. For example, in 1947 an ornithologist on the gulf of Florida, Charles Broley, started witnessing strange things with the eagle population. He observed that the number of eaglets began dropping sharply, and adult eagles began acting peculiar. Specifically the males just didn't have any interest in sex.

He became convinced in later years that 80% of Florida's bald eagles were sterile. Researchers later traced the problem to DDE, an estrogenic by-product of DDT.

News about the estrogenic effects of these insecticides continued to pop up and in 1980 the Tower Chemical Company near Orlando, Florida had a particularly large accident causing DDE to overflow into a nearby creek. This creek then emptied into Lake Apopka. Soon after, a scientific team was called in to investigate the declining number of alligators. They found more than they bargained for. One researcher described that they were witnessing sex-reversal. At least 25% of all male alligators were found to have a deformed penis, mostly reduced in size.

Twenty-five years later, 75% of eggs in the lake are either dead or infertile. This is pretty compelling evidence that there is a strong estrogenic component to this insecticide. The males that did survive were demasculinized. Basically, their endocrine system began producing estrogen rather than Testosterone. To make it even worse, the alligators were not the only animals affected. Researchers found that 20% of all animals in Lake Apopka had some sort of inter-sex condition.

Lake Apopka: Don't Drink the Water

This is pretty scary because everything we see in wildlife has an implication for humans. These chemicals can remain in the environment for years and years, some having half-lives of 25-100 years. So even if we reduced our use of these insecticides over the years, their remains are still around.

In 1992, a team of reproductive specialists from the University of Copenhagen startled the world with the announcement in the British Medical Journal that sperm counts had dropped approximately 50% in the industrialized world since 1938. That was big news. So of course people started looking towards xenoestrogens as a potential cause.

An endangered species??

It is something to be worried about. Has it been concluded, without a doubt, that the cause of this is DDT or some sort of xenoestrogens? No, but it is something to be concerned with.

T: So the evidence is pointing in that direction, but it seems like it would be a hard definite conclusion to draw. Let's face it, what guy is going to volunteer to ingest large amounts of xenoestrogens for the sake of science?

JW: Exactly, these studies would work nicely with mice and rats, but you're not going to find willing human participants.

T: There seems to be a significant amount of environmental data regarding the effects of xenoestrogens and animals, but is there any laboratory data on the effects of xenoestrogens on animals or maybe even humans?

JW: Animal experiments are abundant, but for ethical reasons, scientists can't do experiments on humans like they can do on rats. There have, however, been several studies showing a correlation between xenoestrogens and various health problems.

There are tons of studies showing the bad effects of xenoestrogens on animals. For example with mice, there was a study in which DES was given to pregnant mice for just 2 days and several important changes in male offspring occurred. The newborn mice were hermaphrodites.

There was a feminization of males that occurred early in fetal life when we exhibit both male and female reproductive system. At the molecular level, the males were producing female proteins in their reproductive tract throughout their life. Also, the older mice went on to develop prostate disease. These were some of the first signs that turned people on to the fact that these are definite endocrine disrupters.

Now does that transfer to human? Again there are not any causal studies. People are not volunteering to get loaded up on estrogens and then give their body to science so someone can dissect their ovaries or testicles or something.

There have been plenty of studies showing a correlation between chemicals in the environment and the effects they have on the poor folks that are exposed to them. The earliest one I can think of is the one showing the women in Guatemala who were hitting puberty at 3-4 years old. They think this was caused by being exposed to tons of xenoestrogens.

One of the most recent articles, from just a couple years ago, showed that xenoestrogens can and do collect in our adipose tissue. Researchers took tissue samples from over 400 adults and 75% of the samples were found to have significant levels of xenoestrogens. DDT and its derivatives were present in 98.3% of the samples.

The scary thing is that, firstly, we're all carrying around xenoestrogens in our body fat, and second, it also showed us that different xenoestrogens act together synergistically to magnify their estrogenic properties. Basically the more you have, the more variety you'll have, and thus the more likely the xenoestrogens are going to pronounce themselves in different sorts of effects, from decreased sex drive to more awful things like cancer.

T: You mentioned reduced sperm count already. What are the major negative effects of xenoestrogens for men?

JW: Cancer would be the worst. Men are particularly susceptible to prostrate cancer with increased estrogen exposure; estrogens of any sort, including xenoestrogens. In the slightly less atrocious category, they could also have detrimental effects on your body composition.

A reduction of Testosterone and increase in estrogen can cause increased body fat, reduced muscle mass, and decreased strength. Also, xenoestrogens can cause a weakening of the immune system. Also, they have behavioral implications because of their ability to pass through the blood-brain barrier. People get very emotional when their estrogen levels are high. We're all very familiar with that and probably wouldn't want to inflict that on ourselves.

T: Definitely not. Speaking of high estrogen levels. Since women already have higher levels of estrogen to start out with do xenoestrogens have a negative impact on women?

JW: For sure. They have linked xenoestrogens to breast cancer. For the women, like men, cancer is the worst-case scenario. The evidence is pretty compelling, especially if you look at the increased rates of breast cancer over the past several decades. The possibility that a woman in North America will contract breast cancer has risen from one chance in twenty in 1950, to the current rate of one chance in eight. Every year 182,000 American women will be diagnosed with breast cancer and 46,000 women die of the disease annually.

Basically, exposure to estrogen is recognized by the American Cancer Society as a risk factor for breast cancer. There have been several studies, I'll name one. In 1990, a study at the Hebrew University's Hadassah School of Medicine showed that in the decade between 1976 and 1986, Israel was unique among 28 countries surveyed in that it actually registered a significant drop in breast cancer mortality. What they eventually connected this drop in breast cancer mortality to was a 1978 Israeli ban on the use of three xenoestrogenic pesticides, including DDT

T: Wow. That seems pretty compelling for the argument against xenoestrogens.

JW: Very compelling, but I want to make it clear that I'm not trying to be an alarmist. The studies are far from conclusive, and my stance is basically that there are practical ways to minimize your exposure to xenoestrogens, which I'm sure we'll touch on later.

T: You've mentioned xenoestrogens in pesticides a lot. But I know one of the popular topics is xenoestrogens and plastics. They always seem to be mentioned in the same sentence together. What's the connection there?

JW: Several studies have shown that xenoestrogens can leach from plastic polycarbonates. There is one particular study that I just looked at. The researchers were actually looking at culture medias with different chemicals to see which types of chemicals were estrogenic. They found one solution that was incredibly estrogenic, but it wasn't related to the chemicals that they added. Instead, it was the bottle that they heated the solution in. Basically, they were using Nalgene polycarbonate bottles. Most of us are familiar with Nalgene bottles. I use them too. They are very convenient for drinking water or what not. But when those bottles were heated, in this case 250-degrees Fahrenheit for 30 minutes (this is just beyond the point of boiling for a significant time period), they found rather potent levels of the xenoestrogen, BPA.

They then did a control for the study where they just used distilled water in the Nalgene bottles, heated them up and found the same effect. This is pretty scary news. There have been dozens of studies showing different levels of xenoestrogens coming from plastics, specifically soft plastics. You want to avoid heating up plastics containing food, water, or drinks.

T: That must not have made Nalgene happy.

JW: True, but we can't really pick on Nalgene. The researchers were using Nalgene bottles because they are one of the best brands for strength and reliability. Any plastic bottles would have produced the same results. And let's face it, not many of us are boiling liquid in our Nalgenes for 30 minutes.

T: Let's jump back for a second. You talked about alligators, bald eagles, and all these animals being affected by xenoestrogens. Can they get passed up the food chain? If a fish has been surrounded by these toxins and then I happen to eat the fish, am I at risk? Am I going to be getting a lot of these xenoestrogens?

JW: Absolutely. Xenoestrogens definitely get passed up the food chain. I just looked at a study that showed predatory fish have increased levels of xenoestrogens in their fat tissue, since they're eating other fish who were storing these chemicals in their fat tissue. The same goes for humans.

Xenoestrogens, since they have such a long half-life, remain in the environment and they are stored in your adipose tissue. This is very discouraging because this is how chemicals get passed through a food chain.

T: Okay so plastics are iffy, pesticides are bad, and now xenoestrogens are passed up the food chain. It seems that there is no way a person could avoid xenoestrogens completely. But what are some ways to minimize your exposure to them? You mentioned before you have some tips that you could share with us.

JW: Yeah definitely. Like we discussed earlier it isn't something that you should be so worried about that you can't live life. I still use my Nalgene bottle; I just don't boil water in it. But there are several tips that I have to help decrease your exposure to xenoestrogens in the environment.

As much as possible, try to keep soft plastics, especially polyvinyl chloride (PVC), out of your household, particularly people with kids. The one overriding theme for so many of these studies on the effects of xenoestrogens for humans is that infants, small children, and especially fetuses still in the womb are particularly susceptible to the effects of xenoestrogens. You can really screw up a child by exposing them to high levels of xenoestrogens. If you have kids, try to use glass bottles whenever possible.

T: Soft plastics, does that include Tupperware?

JW: Yeah. The softer the plastic, the worse it is going to be in regards to leaching these chemicals. Particularly with plastics there is a chemical known as phthalates. It is a compound added to plastic to increase its flexibility. There has been a huge stink raised over phthalates in the literature, some people link it to cancer via its estrogenic effects while others say there is no risk at all.

There was a study in 2000 that identified phthalates in high levels in young Puerto Rican girls. This kinda sounds like a funny study, but in fact Puerto Rican girls in general hit puberty at a much earlier age than the rest of the world. They looked at these girls that were hitting puberty at only a few years old and found that they had high levels of phthalates. Scientists are always very cautious not to come to causal conclusions but there is a very strong correlation here. As the age of puberty onset went down, the levels of phthalates were found to be higher. So it seems as if there is something going on there.

My next tip is to shop organic when you can. Admittedly, I don't always follow my own advice. I know eating organic foods is expensive and I know what it is like to be a starving college student. But by eating organic food you're going to decrease your chance of being exposed to pesticide contamination. If you do shop at a regular market, then be careful to thoroughly wash your fruits and vegetables. Buy a soft scrub brush to scrub your fruits and veggies before eating them.

I want to stress that even though there's a chance that you'll consume pesticides by eating fruits and vegetables, you should NOT decrease your consumption of fruits and vegetables. They are your front line of defense against being contaminated by xenoestrogens.

Several varieties of fruits and vegetables have Calcium D-glucarate. This is a botanical extract found in high levels in grapefruit, apples, oranges, broccoli, and brussels sprouts. This extract allows the body to excrete hormones such as estrogen before they can become reabsorbed.

While we're talking about fruits and vegetables, increase your intake of fruits and berries, particularly ones with high antioxidant levels. In particular, be sure to eat black grapes regularly.

Black grapes are nature's best source of resveratrol, a compound that has recently been the subject of numerous studies because of its antioxidant properties and its potential to ward off Alzheimer's disease. Red grapes are also a good source of resveratrol, and moderate red wine consumption could also help. Resveratrol also has antiestrogenic properties, which helps to block xenoestrogens when they try to attach to the receptors in our body. Resveratrol is also found in Biotest's anti-estrogen, testosterone support supplement, REZ-V.

But not all vegetables are good. Canned vegetables should be avoided. Studies have shown that significant quantities of BPA have been detected in canned vegetables and the liquid found in the cans. It is basically a contamination that leaches from the plastic coating of the can interior.

T: I guess that's bad news for Popeye, eating all those cans of spinach.

JW: Yeah definitely. He must have taken some aromatase inhibitors or something.

Another tip is to cut back or eliminate perfumes and air fresheners. Some of these products have compounds called parabens that are xenoestrogens. If you do love to use air fresheners or Hai Karate Cologne, just check on the bottle make sure that parabens aren't listed as one of the ingredients.

You want to avoid plastics for food storage. Buy the glass Pyrex containers for storage and heating of your foods. Like I mentioned before, I still use Nalgene bottles but I never fill them with hot liquids. Also, if you're a coffee drinker, use a stainless steel travel mug rather than one of the soft plastic ones.

Finally, get leaner. As I talked about earlier xenoestrogens accumulate in our bodyfat. As JB's recent article mentioned, some of the various toxins that have accumulated in our adipose have been shown to be released into the bloodstream when people go on a fat loss diet. When combined with a proper nutritional program, this could be your chance to detoxify yourself.

T: Good tips. Well John I think we'll wrap it up there. You've given us tons of great hints and tips to minimize all the extra estrogen in our lives. Let me give you a chance to tell us about what projects you have going on. I had mentioned your FitCasts podcast earlier.

JW: Thanks, Mike. The FitCast is a weekly podcast put together by Kevin Larrabee and myself. We discuss the current fitness and nutrition news along with having a special guest each week. We've had John Berardi, Cassandra Forsythe, Lou Schuler, Craig Ballantyne, Chad Waterbury, Eric Cressey, and Alwyn Cosgrove to name a few. The response has been great; I'm lovin' it. You can find us at or through iTunes.

Also John Berardi and I are working on a revised version of Gourmet Nutrition. We are putting what has already been released into paper format. We've hired a photographer to take pictures of every meal. We are also making it user friendly. Be on a look out for that at the end of the summer.

I sympathize with the folks out there who don't want to have an ebook cookbook. So we've decided to make this a hardcover version. The photos and layout that I've seen so far look incredible.

T: Thanks so much for taking the time to enlighten the T-World to this important topic.

Mike Roussell's academic background in nutrition science, coupled with his broad range of experience with clients, gives him the unique ability to translate scientific findings into relevant, understandable, and actionable strategies that get results. Follow Mike Roussell on Facebook