Dr. Shanna Swan: How to Safeguard Your Hormone Health & Fertility

Dr. Shanna Swan (0s)

• Dr. Shanna Swan is a professor of environmental medicine and public health at the Mount Sinai School of Medicine, and a world expert in how exposure to toxins and compounds in the environment impact reproductive health (17s).
• Her work focuses on how compounds in the air, food supply, water supply, cosmetics, and household items impact the developing fetus, children, and adults at the level of their reproductive biology, including testosterone and estrogen pathways (32s).
• Fertility rates are dramatically dropping from year to year, and testosterone levels and sperm counts are also decreasing, while conditions like polycystic ovarian syndrome are increasing in women (1m5s).
• Simple daily actions can be taken to limit exposure to environmental toxins and their impact on hormone health and fertility (1m28s).
• Dr. Swan emphasizes the importance of taking control of one's health in relation to environmental toxins and endocrine disruptors (1m51s).
• The discussion aims to inform listeners about the impact of environmental toxins on reproductive health and provide actionable steps to safeguard hormone health and fertility (1m40s).

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Environmental Chemicals, Fertility, Hormones, Phthalates (6m49s)

• There are forces, chemicals, and agents in the environment that can affect reproductive health, and the question is when, in whom, and at what dose these effects occur (8m32s).
• The category of focus is primarily man-made chemicals, although other factors such as sleep and exercise also play a role in reproductive health (8m53s).
• Chemicals in the environment can affect fertility, particularly those that are hormone disrupting or endocrine disrupting chemicals, which alter the body's hormones (9m31s).
• Hormone disrupting chemicals can have various effects, and focusing on these chemicals helps identify where to look for their effects, such as which hormone is affected, when, and how (10m13s).
• Much of the discussion centers on the estrogen and testosterone pathways as they relate to masculinization or feminization of the brain and body, as well as sperm and egg quality (10m36s).
• The work of a reproductive epidemiologist, such as the one being discussed, involves studying the effects of various factors, including endocrine disrupting chemicals like oral contraceptives, on reproductive health (10m47s).
• Oral contraceptives are designed to be endocrine disrupting chemicals, changing the body's reproductive hormones, and studying their effects led to a focus on reproductive health (11m3s).
• A large study on oral contraceptives, known as the Kaiser study, was conducted to determine if there were adverse effects of oral contraceptives, for whom, when, and how much, and it was considered a great study (11m21s).
• The study of environmental chemicals, rather than pharmaceuticals, was a focus area for a while, particularly during time spent at the California Department of Health Services (11m41s).
• An "aha moment" occurred while flying to Japan with John Brock, a chemist at the CDC, where he suggested looking into phthalates, which could be measured at the CDC and were found to be present in everybody, including women of reproductive age (12m12s).
• Colleagues at the National Toxicology Program (NTP) had identified something called the "phthalate syndrome," which was explained by John Brock (12m35s).
• The National Toxicology Program is a governmental research center that looks at the toxicity of chemicals, including reproductive, carcinogenic, and neurotoxic effects (12m40s).
• The NTP had signaled out phthalates as being reproductively toxic, specifically to males, and specifically when exposure occurs in utero, meaning when a pregnant mom is exposed to phthalates and the fetus is disrupted (13m4s).

Phthalate Syndrome, Animal Data, Male Offspring (13m30s)

• Phthalates can enter the body through various modes, including ingestion of contaminated food, inhalation, and skin contact, and can potentially pass through the placental barrier to impact fetal development (13m31s).
• In experiments conducted by the National Toxicology Program (NTP), mother rats were fed various doses of phthalates, resulting in changes to the genitals of their male offspring, but no changes were observed in female offspring (14m0s).
• The changes in male offspring included incompletely masculinized genitals, characterized by a smaller penis, less descent of the testes, and internal changes such as undescended testicles and alterations to the epididymis (14m22s).
• The genital tract initially develops as a single ridge in both males and females, and under the influence of testosterone during a specific window (days 9-12 of gestation in rats), it becomes sexually dimorphic (14m39s).
• The distance from the anus to the genitals is a crucial measure of the impact of phthalates on fetal development, and changes in this distance were observed in male offspring exposed to phthalates (16m9s).
• The collection of changes in the male genitals caused by phthalate exposure is referred to as "Phthalate Syndrome" (16m19s).
• Phthalate Syndrome is unique in that it is a syndrome attached to a chemical class, rather than a pharmaceutical or a specific disease (16m36s).
• The effects of phthalates on fetal development are comparable to those of alcohol in Fetal Alcohol Syndrome, and the term "Phthalate Syndrome" was coined to reflect the severity of these effects (19m4s).

Phthalate Syndrome in Humans, Pregnancy & Babies (19m11s)

• Research on the effects of phthalates on human health began with a study on rats, which led to the question of whether similar effects occur in humans (19m16s).
• To investigate this, a study was conducted using stored urine samples from pregnant women, which were analyzed for phthalate metabolites to determine the mother's exposure level (20m8s).
• The study also involved measuring the genitals of the babies, who were on average around 12 months old, to look for any changes that may be linked to phthalate exposure in the womb (21m41s).
• The critical window for phthalate exposure to have an effect on the genitals is very short and delicate, and research on rats has shown that exposure before or after this window has no effect (22m25s).
• The study aimed to draw a potential link between phthalate exposure in utero and external biomarkers, despite the challenges of identifying the critical window for exposure (22m8s).
• The researcher was not concerned about phthalate exposure in the delivery room or early life, as it was unlikely to affect the measures being studied (22m50s).
• Measuring the effects of phthalate exposure on human genitals is challenging due to the small size of newborn genitals and the difficulty of correlating them to the human genital system (23m13s).
• A pediatrician was consulted to help with the study and provide expertise on measuring the genitals of the babies (23m33s).
• A study was conducted to create a method for measuring the anogenital distance (AGD) in humans, which is a common measurement used in animal studies to assess the effects of toxins on reproductive development, particularly in males (23m37s).
• The study found that the best place to measure the AGD in males is where the tissue changes from rugate to smooth tissue, specifically where the scrotum inserts, as this point is clear and easy to measure (24m10s).
• Two other measurements were taken: the anos-scrotal distance and the anop-penile distance, which is the distance from the anus to the anterior insertion of the penis (24m27s).
• The study found that the anos-scrotal distance had the least variance and was the most precise measurement, while the anop-penile distance was less obvious and required more discussion on how to make the measurement (25m6s).
• The study was designed to be repeatable across examiners, and the results showed that the AGD was significantly shorter in mothers who had higher levels of certain phthalate metabolites, specifically the most anti-androgenic phthalates (26m45s).
• The AGD is a dimorphic measurement, meaning it tends to be 50-100% longer in males than females, which makes sense given the anatomical differences between the sexes (27m4s).
• The study related the AGD measurements to the levels of phthalate metabolites in the urine of pregnant women, as measured by the CDC, and found a significant correlation between the two (26m17s).

Hyenas; Phthalate Syndrome in Males (27m30s)

• In all mammalian species, except for two, the male anogenital distance is longer than the female's; the exceptions are hyenas and elephants (27m35s).
• Female hyenas have clitorises larger than some male hyena penises, and they give birth through those clitorises; this is due to the females being heavily androgenized (29m4s).
• In hyena societies, the females are physically and hierarchically dominant, eating first and holding alpha status (29m42s).
• The female hyena's anogenital distance is longer than the male's, which is unusual compared to other species where the male anogenital distance is typically 50-100% longer (29m14s).
• Phthalates such as 3-thades DL hexal Thal, DP dbal Thal, DBP, and butal benzil phthalate (BBzP) are anti-androgenic and testosterone-lowering, and have been associated with a shorter anogenital distance in males (30m22s).
• A study on human males replicated the findings of an animal study, showing that exposure to certain phthalates is associated with a shorter anogenital distance (30m40s).
• A study on human anogenital distance, which began in 2012, is still ongoing and tracking the reproductive function of the children, who are now 12 years old (31m9s).
• The Tides study, also known as the Infant Development Environment Study, collected urine samples from pregnant women in four US cities to examine the effects of phthalate exposure on fetal development (32m4s).
• The Tides study found that exposure to certain phthalates during pregnancy is associated with changes in anogenital distance in newborn males (32m41s).

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Polycystic Ovary Syndrome (PCOS), Mothers & Female Offspring (34m22s)

• Research has shown that anogenital distance in males is approaching the distribution in females, indicating that the male distribution has become more feminized, with characteristics such as smaller penises, less descent of the testes, and smaller scrotums (34m25s).
• Secondary sex characteristics of puberty in males, including Adam's Apple, facial growth, and thickening of the vocal cords, are later-activating effects of hormones, but there may be precursors present in males (35m5s).
• In mice, sexing the animals when they are young requires careful examination, but as they get older, it becomes easier to determine their sex, with males developing visible testicles (35m37s).
• Female offspring of mothers exposed to more testosterone than expected may have a more male-like anogenital distance, indicating a bidirectional effect (36m20s).
• A study found that girls born to women with Polycystic Ovary Syndrome (PCOS), who have excess testosterone, had a longer, more masculine anogenital distance (36m51s).
• Women with PCOS often have elevated levels of androgens, facial hair, and other characteristics, and their daughters may also have a more masculine anogenital distance (37m12s).
• The study population consisted of women with a diagnosis of PCOS, who were taken as a marker of higher testosterone exposure, and their daughters, who were found to have a longer anogenital distance (37m31s).
• The anogenital distance measure is a look inside the womb at the androgen level that the fetus is exposed to, providing a readout of what was present in the fluid at the time, which is typically during the first trimester (38m21s).
• The anogenital distance measure can provide insight into the androgen level that the fetus is exposed to, which can have implications for later fertility (38m55s).

Anogenital Distance & Sperm Count (39m3s)

• The impact of early androgen exposure on fetal development is significant, with masculinizing effects on both male and female offspring, although some of these effects are a result of testosterone being converted into estrogen (39m4s).
• The association between testosterone and masculinity, as well as estrogen and femininity, is often misunderstood, as both hormones play roles in both male and female development (39m51s).
• An external biomarker of fetal androgen exposure, also known as masculinization, can be identified through the mother (40m5s).
• Research on the effects of androgen exposure on fetal development led to a study on a population of college students in Rochester, New York, where anogenital distance (AGD) was measured and correlated with sperm count (40m56s).
• The study assumed that AGD is forever, meaning that if an individual is born with a short AGD for their size, they will still have a short AGD for their size as an adult, adjusted for body size (41m24s).
• The study found that men with longer anogenital distances had higher sperm counts, suggesting a correlation between the two measures (43m7s).
• The study's findings were based on a population of volunteers who were paid $75 to participate and provided semen samples and completed a questionnaire (42m12s).
• The study controlled for body size and weight, among other factors, to normalize the data and account for individual variations (42m47s).
• Earl Gray, a colleague, conducted studies on animals that supported the assumption that AGD is forever (41m15s).
• A study was conducted to examine the relationship between anogenital distance (AGD) and sperm count, with the assumption that AGD measured in adulthood reflects early AGD at birth (43m23s).
• The study found a correlation between AGD and sperm count, but it's a leap of faith to conclude that early AGD at birth is related to sperm count later in life, as early AGD was not directly measured (43m40s).
• Participants in the study were college students who were asked to refrain from alcohol and cannabis for 90 days prior to the study, which is the duration of spermatogenesis (43m57s).
• Despite potential limitations, the study found a robust link between AGD and sperm count (44m11s).
• A colleague, Dr. Mike Eisenberg from Stanford, conducted a separate study on men in an infertility clinic and found that men who had fathered children had a longer anogenital distance than those who had not (44m27s).
• The study by Dr. Eisenberg compared men who were having challenges with fertility to those who were successful in having children, and not those who had opted out of having children (44m41s).
• Measuring AGD in adult men is a different process than measuring it in newborns, and research has been conducted to develop a method for accurately measuring AGD in adult men (44m52s).

Sperm Count & Fertility (45m3s)

• A study among pregnancy planners in Denmark found a correlation between sperm count and time to pregnancy, showing a steep increase in conception probability with sperm counts between 40-45 million per milliliter, and then leveling off after 50 million per milliliter (45m49s).
• The study's findings indicate that sperm count matters significantly for fertility if it's low, but not at all if it's high, with 100 million sperm per milliliter being a point of diminishing returns (48m0s).
• Below 45 million sperm per milliliter, the sperm count really matters, and the probability of conception drops off precipitously, while above 75-100 million per milliliter, sperm count no longer affects fertility (48m42s).
• Sperm counts can range from very low (8-10 million per milliliter) to zero, or as high as 400 million per milliliter, with this range being influenced by factors such as age, genetics, and environmental exposure (49m3s).
• The relationship between sperm count and fertility is not always linear, with quality also playing a role, as nature "runs a probability game" by overproducing sperm in the hopes that the best quality sperm will fertilize the egg (48m15s).
• Discussions about sperm count and fertility have been had with experts such as Robert Spolski and Mike Eisenberg, highlighting the complexity and nuances of the topic (45m21s).

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Sperm Count Decline (51m11s)

• Research has shown that sperm counts are dropping, and there is a relationship between anogenital distance and Thal exposure, which may be functionally relevant to the decline in fertility (51m11s).
• The decline in fertility is also related to women with elevated androgens, which will be discussed later (51m29s).
• Sociobiology and economics also play a role in the decline in fertility, as people are opting out of having kids (51m41s).
• The introduction to phthalates was not initially through sperm count, but rather through a colleague's question that led to a journey of research (51m57s).
• In the late 1990s, a committee of the National Academy of Sciences was assembled to look at whether hormonally active chemicals, or endocrine disrupting chemicals, in the environment posed a threat to human health (52m15s).
• A study from Denmark claimed that sperm count had dropped 50% in 50 years, which was a huge drop, and this claim was examined by the committee (52m55s).
• The initial reaction to the study was skepticism, but after examining the data and considering possible confounders, the decline in sperm count was found to be real (53m22s).
• Possible confounders that were considered included changes in the method of counting sperm, differences in the men being studied, and lifestyle factors such as obesity and smoking (54m10s).
• A multivariable model was created to extract information on all the factors that could explain the decline, and the results showed that the slope of the decline was exactly the same (55m13s).
• Dr. Shanna Swan conducted a study on sperm counts and found that the numbers were going down over time, which led to further investigation into the factors that could impact the result. (55m56s)
• To ensure the accuracy of the study, Dr. Swan considered various factors that could affect sperm count, such as smoking, cannabis use, alcohol consumption, frequency of ejaculation, and the requirement to abstain from ejaculation for a certain period before the test. (56m12s)
• The study's methodology was meticulous, taking into account the potential for participants to not faithfully report their behaviors and assuming an equal distribution of truthful and untruthful responses. (56m46s)
• Dr. Swan's research involved multiple studies, including a follow-up on sperm count studies across multiple years, starting from 1992, then 2017, and subsequent updates, demonstrating her thoroughness and attention to detail. (57m20s)
• Dr. Swan's background in math, statistics, and probability theory contributed to her rigorous approach to the study, ensuring that the results were reliable and not based on simplistic correlations. (57m35s)
• The discussion emphasized the importance of good scientific method, particularly in human epidemiological work, where there are many potential confounding variables that need to be considered. (58m10s)

Sperm Quality & Pesticides (58m19s)

• A study was conducted to investigate the decline in sperm count, which was found to be declining over the past 50 years, spanning two generations, indicating that the cause is likely environmental rather than genetic (58m44s).
• The study involved selecting men from four cities in the United States with different environments and analyzing their urine, blood, and semen quality to identify potential environmental factors contributing to the decline in sperm count (59m32s).
• The study found that men living in Central Missouri, an area with high pesticide use, had half as many moving sperm as men in Minneapolis, suggesting a link between pesticide exposure and sperm quality (1h1m49s).
• Within Missouri, a sample of men with high and low sperm parameters was analyzed, and it was found that five pesticides were significantly higher in the men with low sperm parameters, including motility and morphology (1h2m18s).
• The study's sample consisted of partners of pregnant women, who were considered a representative sample of the larger population, as they all receive medical care and their partners are likely to provide a semen sample (1h0m44s).
• The study's findings suggest that exposure to certain pesticides may be a contributing factor to the decline in sperm count and quality (1h2m21s).
• A study was conducted in Columbia, Missouri, where researchers measured the urine of men for pesticide metabolites, specifically looking at exposure to pesticides used in the area, not from eating corn and soybeans, but from living in an area where pesticides are used (1h2m41s).
• The study found metabolized pesticides in the men's urine, indicating exposure through the air or possibly from eating contaminated corn and soybeans, but the exact route of exposure is unknown (1h3m2s).
• The men in the study were not specifically farmers, but rather husbands of pregnant women receiving prenatal care at the University of Missouri, who agreed to participate in the study (1h3m25s).
• The study measured the presence of five pesticides, including atrazine, which is one of the most widely used pesticides globally, and is commonly used in the commercial pesticide field (1h3m54s).
• Atrazine is a significant player in the pesticide industry, with high usage around the world, making it a relevant theme in the study of pesticide exposure (1h4m1s).

Atrazine, Amphibians, Sexual Dimorphism, Behavior (1h4m12s)

• Research by Tyrone Hayes has established a link between atrazine exposure and male sexual behavior in amphibians, showing that a significant number of frogs exposed to atrazine chose to mate with other male frogs, indicating a neural change (1h4m40s).
• This change is likely due to a neuroendocrine alteration, as mounting behavior is controlled by the hypothalamic nuclei, and studies have shown that the organization of neural circuits and neuroendocrine pathways controlling sexual preference can be impacted by atrazine (1h5m43s).
• The brain, like the genitals, is sexually dimorphic, meaning it has different structures and functions in males and females, which does not imply better or worse, just different (1h6m56s).
• Studies have shown that sexual dimorphism in the brain is present in various species, including beagles, and is dependent on testosterone and estrogen levels during development (1h7m49s).
• The link between sexual dimorphism in the brain and behavior can be explained by ethologically relevant and evolutionarily logical arguments, but caution is needed when applying these findings to humans and specific abilities or traits (1h8m1s).
• Research has also shown that prenatal exposure to certain environmental chemicals, such as phthalates, can impact neurodevelopmental outcomes, highlighting the importance of considering the effects of environmental chemicals on brain development and function (1h6m49s).
• The discussion around sexual dimorphism in the brain and its implications for behavior and abilities can be complex and sensitive, and it is essential to approach the topic with nuance and avoid oversimplification or misinterpretation (1h8m51s).

Preschoolers, Phthalate Exposure, Sexually Dimorphic Behaviors (1h9m0s)

• A study used a simple, outdated questionnaire called the PSAI (Pre-School Activities Inventory) to assess play behavior in preschoolers, which included 24 questions about sexually dimorphic behaviors such as playing with dolls, dressing up, and rough-and-tumble play (1h9m0s).
• The study found that higher levels of phthalate exposure, which are anti-androgenic, were associated with less masculine male-typical play in boys, specifically less rough-and-tumble play, at the age of four (1h10m5s).
• The study's findings suggest that exposure to phthalates during a critical period of development may affect the development of sexually dimorphic behaviors in children (1h10m24s).
• The concept of dimorphism refers to the differences between male and female brains, which are typically defined by the presence of a Y chromosome, but it's essential to acknowledge that these differences are not absolute and exist on a spectrum (1h10m41s).
• The study's results showed that boys exposed to phthalates were more likely to engage in traditionally feminine behaviors, such as playing dress-up and having tea parties, but this does not mean that all exposed boys will exhibit these behaviors (1h11m57s).
• Sociobiological variables, such as having a sibling of the opposite sex, can also influence play behavior, and the study controlled for these factors (1h12m14s).
• The study also controlled for parents' attitudes towards same-sex play and found that these attitudes can impact a child's behavior (1h12m52s).
• The researcher notes that none of these factors are deterministic, and individual differences play a significant role in shaping behavior (1h12m47s).
• The researcher shares a personal anecdote about growing up in a household with strong messages about gender-appropriate play and how this influenced their behavior (1h13m17s).
• The researcher mentions that cultural context, such as the time period and societal norms, can also impact the development of sexually dimorphic behaviors (1h13m51s).

Tools: Lowering Exposure to Endocrine Disruptors, Fertility (1h14m8s)

• Phthalates are not just found in pesticides, but also in other products, and pesticides are not the worst source of hormonally active exposures. There are different classes of exposures, including phthalates, bisphenols like BPA, and certain metals, which can be found in various products and activities in daily life (1h14m8s).
• The top sources of endocrine disruptors that people have agency over include food, food packaging, food storage, and cooking utensils, as these are used frequently and can be controlled (1h16m6s).
• Food and beverages are also major sources of exposure to endocrine disruptors, and making changes to these can have a significant impact (1h16m42s).
• A movie featuring six infertile couples found that by identifying and changing the products they used, such as facial care, shampoo, cleaning products, laundry detergent, and food storage, they could reduce their exposure to endocrine disruptors (1h17m4s).
• Fragrance products, including perfumes, lotions, soaps, and essential oils, are a major source of exposure to endocrine disruptors, and avoiding these products can help reduce exposure (1h18m23s).
• To safeguard hormone health and fertility, it's essential to avoid products with fragrances, such as spray deodorants, roll-on deodorants, laundry detergent, and soaps, as they can affect hormones if their scent is noticeable (1h18m52s).
• Another crucial step is to get rid of plastics used for food storage containers, as well as non-stick pans containing posos chemicals, to reduce exposure to harmful substances (1h19m35s).
• A study was conducted where six couples received a box of alternative products, including straws, bamboo spoons, and other items, worth approximately $500, to reduce their personal exposure to chemicals (1h21m1s).
• The couples made changes to their daily lives by using these alternative products, and although the data is not yet conclusive, they reported feeling happier, sleeping better, and having more energy (1h21m55s).
• The study focused solely on the impact of product-related changes, without addressing other factors such as obesity, which may be explored in a separate study (1h20m13s).
• The chemicals reduced in the study are also known as obesogens, which can increase obesity, and reducing exposure to these chemicals may have a positive impact on weight management (1h20m36s).
• The couples were happy to continue making these changes after the study, and a follow-up will be conducted to see if they maintained these changes and if it had a positive impact on their fertility (1h22m16s).
• Data was collected on whether the couples were able to conceive after making these changes, but the results cannot be disclosed until the study is complete (1h22m27s).
• For individuals having trouble conceiving for 12 months or more, replacement intervention products can be a good place to start or explore, as they are not harmful and may be cost-saving (1h22m55s).
• Drinking out of plastic bottles can be harmful due to endocrine disruptors, and alternatives such as mason jars or ceramic mugs can be used instead (1h23m30s).
• Some ceramic mugs may have linings with endocrine disruptors, so it's essential to be mindful of the materials used (1h23m43s).
• Buying in bulk and using glass jars instead of plastic containers can improve endocrine status and fertility while also being cost-effective (1h24m0s).
• Shopping for produce without plastic wrapping can be cheaper, as seen in the example of freestanding lettuce being less expensive than wrapped lettuce (1h24m37s).
• Making conscious choices about consumables and avoiding products with endocrine disruptors can have a positive impact on hormone health and fertility (1h23m54s).

Tools: BPA, BPS, BPF & Can Linings; Drinkware; Plastics & Microwave (1h24m52s)

• Reducing fluid intake from plastic vessels is a primary step in minimizing exposure to PA and forever chemicals, with the primary source of BPA being the lining of cans, including those containing drinks, soups, and other food items (1h24m53s).
• BPA has relatives such as BPS and BPF, which are also estrogenic and used as alternatives in BPA-free products, making them just as harmful (1h25m29s).
• Phthalates, on the other hand, are anti-androgenic and used to make plastic soft, while BPA makes plastic hard, and both are undesirable (1h25m48s).
• Manufacturers have started selling BPA-free products, but these often contain BPS or BPF instead, which are equally harmful (1h26m6s).
• To minimize exposure, it is recommended to drink from glass, ceramic, or metal vessels, but not metal cans or aluminum cans (1h27m43s).
• Microwave-safe plastics do not necessarily mean they are safe for use in the microwave, as the plasticizers in the plastic can leach into food when heated (1h28m1s).
• It is advised to never put plastic in the microwave, as the heat can cause the chemical additives to leach into food (1h28m8s).
• Even if plastic containers are not heated, the chemical additives can still leach into food, especially when exposed to sunlight or warm temperatures (1h28m41s).
• Eliminating exposure to these chemicals can be straightforward once understood, but it can be challenging when it comes to nuanced situations, such as buying meat or produce wrapped in plastic (1h29m12s).
• In some cases, it may be possible to minimize exposure by rinsing food items that have come into contact with plastic, but the effectiveness of this method is unknown (1h29m41s).
• Overall, the best approach is to avoid drinking from cans and plastic bottles, not microwave plastic, and avoid plastic intake in general, with the option to buy organic produce when possible (1h30m1s).

Tools: Buying Organic; Skin Products, Fragrance; Sunscreens, Consumer Guides (1h30m7s)

• To safeguard hormone health and fertility, it is essential to avoid pesticides and phthalates, which are added to pesticides to increase absorption and are also found in personal care products like hand cream, lipstick, and fragrances that hold scent and color (1h30m10s).
• Phthalates are absorbed by the body and can have negative effects, so it is crucial to choose products that do not contain them (1h30m17s).
• When it comes to sunscreens, mineral-based options like zinc oxide and titanium dioxide are safer than chemical sunscreens, which can be absorbed by the body and cause harm (1h31m24s).
• While UV damage to the skin can cause certain cancers, there are ways to protect oneself from the sun, including physical barriers like clothing and hats (1h31m43s).
• To find a safe sunscreen, it is recommended to hunt carefully for products that do not contain harmful chemicals and to use resources like the Environmental Working Group's Consumer Guides, which provide ratings and information on various products (1h32m18s).
• The Environmental Working Group's Consumer Guides allow users to search for products, including sunscreens, and receive a rating and information on the product's safety and potential hazards (1h32m31s).
• When searching for a sunscreen on the Environmental Working Group's website, a rating of less than 10 indicates that the product is safer, and the website provides information on why the product received its rating, independent of any funding influences (1h32m50s).

Funding (1h32m58s)

• Funding for research comes from various sources, and people often question the origin of funding due to potential biases (1h32m58s).
• The researcher is a part-time, tenure professor at Mount Sinai and receives some salary, but also has a funder who supported the sperm decline analysis and book publicity (1h33m8s).
• The funder is a philanthropic foundation, and the amount of money provided is not substantial, which reduces the likelihood of biased results (1h33m30s).
• The researcher is careful not to endorse any products to avoid complications and maintain the integrity of the research (1h33m43s).
• The importance of transparency in funding sources is highlighted, as people have become more aware of potential biases in studies, such as those that led to the creation of the food pyramid (1h33m56s).
• The researcher acknowledges that funding sources can be a sensitive topic, especially when it comes to personal choices like diet and body care products, which are often tied to psychological and emotional issues (1h34m15s).

Tools: Distilling Water, Shoes, Clothing, Food Sourcing; Building Materials (1h34m31s)

• To safeguard hormone health and fertility, it is recommended to distill water instead of using reverse osmosis, as distillation can remove more endocrine disruptors, and use the distilled water for drinking, coffee, tea, and cooking (1h35m26s).
• Leaving shoes at the door can help reduce exposure to endocrine disruptors, as dust can contain chemicals like PFOS, which can be tracked into homes on shoes (1h36m30s).
• Being mindful of the products used on the skin is important, and checking their ingredients through resources like the Environmental Working Group can help minimize exposure to endocrine disruptors (1h36m50s).
• Buying organic produce, when possible, can also help reduce exposure to endocrine disruptors, as organic farming tends to use fewer chemicals (1h37m1s).
• Clothing can also be a source of endocrine disruptors, particularly workout wear, as the body can absorb chemicals from synthetic materials and dyes when sweating (1h37m24s).
• Opting for cotton or natural fibers and plant-based dyes can help minimize exposure to endocrine disruptors from clothing (1h37m52s).
• Building materials and furniture can also contain endocrine disruptors like PFOS and PFAS, making it essential to be aware of the materials used in homes and workplaces (1h38m14s).
• Building a town that is toxic-free is a challenging task, requiring careful consideration of the materials used in furniture and building materials, as well as the overall design of the town (1h38m24s).
• To achieve this goal, one approach is to do the opposite of what is depicted in the opening scene of The Simpsons, which features a three-eyed fish and a chemical plant, and instead aim to create a safe and healthy environment (1h38m52s).
• When it comes to food sourcing, it can be difficult for people to access non-fruit and non-vegetable products from safe sources, such as eggs from farms, especially for those who do not live in areas with easy access to farmers' markets (1h39m14s).
• One potential solution is for people to demand safer and healthier options, which could lead to greater availability and affordability of these products (1h39m42s).
• Being aware of the importance of safe and healthy living is a crucial step towards making positive changes, and individuals who are aware of these issues will be more likely to find ways to make a difference (1h40m3s).

Europe vs. US Chemical Safety, REACH Program (1h40m12s)

• Years ago, there was a lot of discussion about dyes in children's toys, especially those from overseas, and the potential harm they could cause to kids who often gnaw on them. (1h40m13s)
• As a result of research and work done in this area, BPAs were banned from sippy cups, and there are laws and restrictions in place to minimize exposure to certain chemicals in young kids. (1h40m32s)
• However, after age 12, there is less regulation, and it's largely up to individuals to make informed choices about the products they use. (1h41m8s)
• Europe has a policy called REACH, which requires companies to show that a chemical is safe before it's put into the marketplace, unlike in the US where chemicals are often put into the market first and then studied for potential harm. (1h41m51s)
• This difference in approach has led to many chemicals being banned in Europe that are still widely used in the US, including in food and personal care products. (1h41m34s)
• One example of a chemical that is prevalent in the US but has been restricted in some contexts is DEHP (di(2-ethylhexyl) phthalate), a type of phthalate that is used in IV bags and other medical equipment. (1h43m15s)
• A bill was recently passed in California banning the use of DEHP in IV bags, which is seen as a positive step, but it highlights the challenges of making changes to the use of chemicals in products. (1h43m31s)
• Companies like B. Braun, which makes hospital products, are working to develop alternative products that are safer for human health, such as IV bags made from alternative materials. (1h44m4s)
• The safety of chemicals like polyphant is uncertain, making it difficult for scientists to determine what it means for a chemical to be safe (1h44m25s).
• Despite the uncertainty, it is known that some chemicals are safer than others, and there are certain "bad actors" that people should avoid exposure to (1h44m48s).
• Don Kennedy, a former president of Stanford, later directed the FDA, indicating that there may be interest in health at high levels, but there is still a problem that needs to be addressed (1h45m11s).
• One potential solution is to focus on what individuals can control in their own homes, as it can be challenging to know what restaurants are doing in their kitchens (1h45m51s).
• Some people are avoiding seed oils, which has become a significant issue for some, but it is unclear whether this is a more significant problem than other health concerns (1h46m5s).
• Olive oil is a preferred alternative to seed oils for some individuals (1h46m15s).

Tool: Pregnancy & Fetal Health (1h46m20s)

• Exposure to endocrine disruptors during pregnancy can have lasting effects on the fetus, and individuals may have limited ability to reverse these effects later in life (1h46m22s).
• Research has shown that if a male's mother smokes during pregnancy, he may experience a 50% reduction in sperm count, which cannot be reversed by changes in his adult life (1h47m11s).
• However, if a male smokes as an adult, he can experience a similar reduction in sperm count, but stopping smoking can restore his sperm health (1h47m32s).
• The effects of exposure to endocrine disruptors during pregnancy can be long-lasting and may affect not only the individual but also their children and grandchildren (1h48m9s).
• Germ cells, which produce eggs and sperm, are formed during fetal development and can be affected by exposure to endocrine disruptors, potentially impacting the health of subsequent generations (1h48m15s).
• Some research suggests that the effects of exposure to endocrine disruptors can last for up to seven generations, although the exact number is not certain (1h48m44s).
• Individuals who are planning to conceive or are pregnant have a responsibility to reduce their exposure to endocrine disruptors to minimize the risks to their child's health (1h48m3s).
• There are practical steps that individuals can take to reduce their exposure to endocrine disruptors, and resources such as the book "Count Down" can provide guidance on how to do so (1h49m6s).

Plastics & Environmental Concern; Fertility (1h49m23s)

• There is a large, international community of scientists, concerned citizens, and activists working to address the issue of endocrine disruptors, including those found in plastics and pesticides, with funding from organizations such as the NIH and the EU (1h49m56s).
• A global Plastics treaty is currently under negotiation, involving hundreds of scientists and concerned individuals working to control exposure to plastics and other chemicals (1h50m4s).
• While plastic is a significant concern, it is not the only issue, and other classes of chemicals, such as pesticides, also pose a threat to human health and fertility (1h50m50s).
• The use of plastics has increased significantly over the past 75 years, and this has been linked to a decline in fertility and reproductive competence (1h51m35s).
• Despite an increase in lifespan, largely due to reductions in smoking and infectious diseases, the use of plastics has not contributed to this increase, and instead, may be driving a decrease in fertility (1h52m9s).
• The shift in population demographics, with fewer young people and more older individuals, poses a significant problem for societies, as the smaller support group at the bottom of the population pyramid cannot support the larger group at the top (1h53m21s).
• This issue is not unique to one country, but is a global problem, with birth rates declining significantly in many societies (1h53m37s).
• The decline in fertility is a significant challenge worldwide, with limited options to counter it (1h53m38s).
• The World Bank has a website called "Fertility Data" that provides information on fertility rates for each country and year (1h54m1s).
• Fertility rates have declined by about 50% in 50 years, similar to the decline in sperm count (1h54m26s).
• A total fertility rate of 2.1 is considered replacement level, meaning two people replace themselves, and a rate below this indicates a shrinking society (1h54m45s).
• Many countries, including the United States, have fertility rates below the replacement level, with South Korea having the lowest rate at 0.78 and Japan at 1 (1h55m4s).
• Large parts of the world are not replacing themselves, and the reasons behind this decline are complex and open to discussion (1h55m13s).
• The decline in fertility is not solely due to sperm count, but rather a broader issue (1h55m24s).

Sperm Quality, Fertility, Cell Phone, Temperature (1h55m26s)

• A study was conducted to assess the impact of electric blankets on fertility in women, but the actual focus was on the outcome of their pregnancy and fertility if they got pregnant (1h55m49s).
• There is currently no convincing evidence that the use of cell phones or exposure to electromagnetic radiation affects pregnancies and fertility, although it is acknowledged that this does not necessarily mean it is not happening (1h56m19s).
• Cell phone use, specifically keeping the phone in the pocket, may have heat effects that could potentially impact sperm count and motility, but there is no evidence of direct effects of electromagnetic fields (EMFs) on sperm (1h56m45s).
• Heat is known to be related to fertility and sperm count, as seen in lower birth rates during warmer months in warmer climates (1h57m17s).
• Research is ongoing to investigate the potential link between cell phone use and fertility, particularly in relation to heat effects (1h57m32s).
• Sitting for extended periods, obesity, or having large legs can cause heating of the scrotum, which has been shown to reduce sperm count, as heat is not beneficial for sperm (1h57m48s).
• The scrotum has features that help regulate temperature, moving the testicles closer to or further from the body to maintain optimal conditions for sperm (1h57m58s).

Other Animals & Fertility Decline, Ecosystems (1h58m4s)

• There is evidence that girls are entering puberty earlier, while women are undergoing perimenopause and menopause earlier, with potential consequences including premature ovarian failure and reduced egg production (1h58m4s).
• Research has linked the earlier onset of menopause to exposure to certain chemicals, although the specific class of chemicals is not specified (1h58m19s).
• Fertility decline is not unique to humans, as many animal species are also experiencing declining fertility rates, which cannot be attributed to delayed childbearing or contraception use (1h59m48s).
• The decline in fertility in non-human species has been linked to the use of pesticides, which have been affecting animals for at least 40 years (2h0m3s).
• The decline of certain species, such as the Florida panther and the black-footed ferret, has significant downstream consequences for ecosystems, highlighting the interconnectedness of species and the potential for a domino effect (2h0m31s).
• The loss of one species can have far-reaching consequences for entire ecosystems, and it is conceivable that humans could eventually be added to the endangered species list due to the impact of environmental factors on fertility and ecosystems (2h1m42s).

Advancing Technologies, Fertility, Offspring & Adverse Effects (2h1m58s)

• Medically assisted conception methods have been developed to help with fertility issues, including techniques such as ICSI (Intracytoplasmic Sperm Injection), where a single sperm is injected into an egg to fertilize it (2h2m0s).
• There are concerns about whether the offspring of these medically assisted conceptions are the same as those conceived naturally, in terms of genetic probability and robustness (2h2m25s).
• New technologies are being developed to assist with fertility, such as Gam Genesis, which allows for the creation of an embryo from a skin cell, using transcription factors to produce a sperm cell and an egg cell (2h2m52s).
• Three-party IVF is a technique used to prevent mitochondrial disease, where the nucleus of one egg is transferred into another egg with healthy mitochondria, resulting in a child with three genetic parents (2h3m32s).
• This technique is currently only allowed in the UK and is illegal in the United States, but it has the potential to allow women of any age to have their DNA propagated forward, provided they still have eggs (2h4m2s).
• The development of these technologies raises questions about the potential adverse effects on the offspring, which can be challenging to determine due to the complexity of the factors involved (2h5m5s).
• It is difficult to know whether any adverse effects seen in offspring are due to the assisted reproduction method or pre-existing fertility issues in the parents (2h5m42s).
• The problem of determining the effects of assisted reproduction on offspring is complex and challenging, but also fascinating, and will likely be solved through continued advancements in medical technology (2h6m0s).

Tool: Consumer Guides, Personal & Household Products (2h6m2s)

• A question was put out on X (formerly Twitter) about hosting an expert in endocrine disruptors, phthalates, and pesticides, and their reproductive implications, which led to many excellent questions from the audience (2h6m3s).
• Some of the questions asked included whether tap water is safe and what can be done to make it safer, with options including distillation and reverse osmosis with remineralization (2h6m31s).
• Questions were also asked about cosmetics and laundry detergents, with a suggestion to use hydrogen peroxide instead of bleach (2h6m50s).
• A company called Million Marker was mentioned, which provides a service where customers can send in their urine for testing to see what endocrine disruptors are present in their body (2h7m52s).
• The person running Million Marker, Genoa, is a Chinese-American and a friend of the speaker, and she is knowledgeable about products that are safe to use (2h7m39s).
• A study was mentioned that showed the dangers of food dyes, specifically yellow number five, which is used in foods like Cheetos and can have severe health effects (2h8m37s).
• Many household items, such as soaps, body wash, cleaning sprays, floor cleaners, and laundry cleaners, can contain endocrine disruptors unless careful attention is paid to finding safe alternatives (2h9m20s).

Tool: Receipts; Thyroid System; Non-Stick Pans (2h9m39s)

• Receipts can be a source of endocrine disruptors, specifically BPA and other chemicals, which can be absorbed into the body, and it is suggested to opt for electronic receipts instead (2h9m39s).
• Endocrine disruptors can have an adverse effect on the thyroid system, and there is a whole field of study on this topic, with evidence showing negative impacts (2h10m2s).
• The impact of endocrine disruptors on the thyroid system may also affect the immune response, particularly in relation to vaccination, although more research is needed to confirm this (2h10m39s).
• The detoxification of endocrine disruptors from the body depends on the class of chemicals, with water-soluble chemicals like phthalates and bisphenols leaving the body within hours, while fat-soluble chemicals like PFOS and pesticides persist for longer periods (2h11m18s).
• Non-stick pans are a source of endocrine disruptors, and it is recommended to use seasoned iron pans instead, as they pose no risk (2h11m59s).
• Europe has more stringent laws regarding endocrine disruptors, and there are many questions about the effects of specific chemicals like atrazine and the impact of ointments and fragrances on hormone health (2h12m12s).
• The work of researchers in the field of endocrine disruptors is crucial in raising awareness about the potential harm caused by these chemicals and the importance of taking action to minimize exposure (2h13m18s).
• The possibility of human extinction due to the destruction of biological ability to reproduce is a real concern, and it is essential to acknowledge and address this issue (2h13m51s).
• Educating the public about the risks associated with endocrine disruptors and promoting awareness about the importance of minimizing exposure is crucial in creating a sense of agency and possibility for change (2h14m51s).

Zero-Cost Support, YouTube, Spotify & Apple Follow & Reviews, Sponsors, YouTube Feedback, Protocols Book, Social Media, Neural Network Newsletter (2h15m18s)

• To access additional resources related to Dr. Shanna Swan's work, including her books, please see the links in the show notes and captions (2h15m18s).
• For more information on microplastics and endocrine disruptors, a solo episode of The Huberman Lab podcast is available and linked in the show note captions (2h15m32s).
• To support the podcast at no cost, please subscribe to the YouTube channel, follow the podcast on Spotify and Apple, and leave a review on both platforms (2h15m42s).
• The podcast's sponsors are mentioned at the beginning and throughout the episode, and supporting them is the best way to support the podcast (2h15m56s).
• Questions, comments, or topic suggestions for The Huberman Lab podcast can be left in the YouTube comment section (2h16m8s).
• A new book titled "Protocols: An Operating Manual for the Human Body" is available for pre-sale at protocolsbook.com, covering protocols for sleep, exercise, stress control, focus, and motivation (2h16m14s).
• The book is based on over 30 years of research and experience and provides scientific substantiation for the included protocols (2h16m23s).
• To stay updated on science and science-related tools, follow Huberman Lab on social media platforms, including Instagram, X (formerly Twitter), Threads, Facebook, and LinkedIn (2h16m54s).
• The Neural Network Newsletter is a free monthly newsletter that includes podcast summaries and protocols in the form of brief PDFs, available at hubermanlab.com (2h17m18s).
• The newsletter covers topics such as deliberate cold exposure, heat exposure, optimizing dopamine, and improving sleep, all available at zero cost (2h17m25s).
• To access the newsletter, go to hubermanlab.com, scroll down to the newsletter section, and enter your email address (2h17m40s).