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Yes, this finding is important , but what should be also noted is this sentence in the article: "He also noted that it may not be a disease itself, but the treatment for the disease, that's actually responsible for reproductive malfunction." It has been known for decades that men's sperm is affected by environmental chemicals (such as pesticides), alcohol, smoking, and medications. So it's important to figure out if it's the medicine or the health condition that's causing the problem - or perhaps it's both. From Science Daily:

Infertility is a warning: Poor semen quality linked to hypertension, other health problems

A study of men who were evaluated for the cause of their infertility finds previously unknown relationships between deficiencies in their semen and other, seemingly unrelated health problems. A study of more than 9,000 men with fertility problems has revealed a correlation between the number of different defects in a man's semen and the likelihood that the man has other health problems.

The study, conducted by investigators at the Stanford University School of Medicine, also links poor semen quality to a higher chance of having various specific health conditions, such as hypertension, and more generally to skin and endocrine disorders....A study Eisenberg co-authored a few years ago showed that infertile men had higher rates of overall mortality, as well as mortality linked to heart problems, in the years following an infertility evaluation. 

In the new study, Eisenberg and his colleagues analyzed the medical records of 9,387 men, mostly between 30 and 50 years old, who had been evaluated at Stanford Hospital & Clinics (now Stanford Health Care) between 1994 and 2011 to determine the cause of their infertility. ...So, using the database, the investigators were able to compare the overall health status of men who had semen defects to that of the men who didn't.

With a median age of 38, this was a fairly young group of men. However, 44 percent of all the men had some additional health problem besides the fertility problem that brought them to the clinic. In particular, the investigators found a substantial link between poor semen quality and specific diseases of the circulatory system, notably hypertension, vascular disease and heart disease. 

In addition, as the number of different kinds of defects in a man's semen rose, so did his likelihood of having a skin disease or endocrine disorder. When looking at the severity of all health problems, the scientists observed a statistically significant connection between the number of different ways in which a man's semen was deficient and the likelihood of his having a substantial health problem.... He also noted that it may not be a disease itself, but the treatment for the disease, that's actually responsible for reproductive malfunction. He said he is exploring this possibility now.

This article mentions a few of the other issues that are linked with male infertility.While incomplete, at least it mentions smoking, BPA exposure, binge drinking, obesity, and lack of sleep.From Medical Daily:

Your Sperm And Your Health: What Your Semen Can Tell You About Your Health

The following article focused on other links to male infertility. It also discussed an interesting 2012 study that looked at the effects of wearing tight briefs (which heats the genitals) versus boxers on sperm production (hint: briefs had very negative effect). From Five Thirty Eight Science:

Men, Those Tightie Whities Really Are Killing Your Sperm Count

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Much has been written about boxing, concussions, and brain damage, but this is the first time I've read about mixed martial art fighters also having such problems. But it makes sense. From Medscape:

Fight Exposure Linked to Reduced Brain Volume

The more boxers and martial arts practitioners experience head trauma, the more likely they are to have lower brain volume, particularly caudate and thalamus volume, according to a new study. Lower brain volume in these fighters correlated with reduced processing speed, the study also found.

These results "suggest that greater exposure to head trauma is related to detectable brain structural and performance deficits in active fighters," the authors, led by Charles Bernick, MD, Lou Ruvo Center for Brain Health, Cleveland Clinic, Las Vegas, Nevada, conclude.

The analysis included 224 adults, aged 18 to 44 years, who were participants in the Professional Fighters Brain Health Study, a longitudinal cohort study of boxers and mixed martial arts (MMA) fighters. The participants included 93 boxers and 131 MMA fighters.The length of professional fighting in this group ranged from 0 to 24 years, with a mean of 4 years. The number of professional fights ranged from 0 to 101, with a mean of 10 fights.

The study also included a control group of 22 age- and education-matched participants with no history of head trauma who did not play a sport associated with head injuries from high school onward.Participants were assessed at baseline and then annually for 4 years. Researchers measured cognitive function with a computer-based battery consisting of tests of  verbal memory, processing speed, and other functions. They used MRI to assess brain volumes.

The study found that increasing exposure to head trauma, as measured by the number of professional fights or years of professional fighting, was generally associated with lower brain structural volumes, particularly subcortical structures. The most consistent relationship between exposure variables and brain volume was seen in the thalamus and caudate. 

The thalamus acts as a "gateway" to the cortex and when affected can influence many neurologic functions, said the authors. It and the caudate are vulnerable to volumetric loss through several mechanisms. Rotational movement of the head brought on by punches in boxing or MMA can result in diffuse axonal injury in white matter tracts, they note.

For the most part, brain structure volumes were lower for boxers than MMA fighters or controls. This could be due to several factors, the authors write. "Perhaps the most obvious explanation is that boxers get hit in the head more. In addition to trying to concuss (ie, knock out) their opponent, MMA fighters can utilise other combat skills such as wrestling and jiu jitsu to win their match by submission without causing a concussion."

The study also found that processing speed was correlated with reduced volume in several cortical and subcortical structures. Reduction in processing speed, said the authors, is consistent with repeated concussions and is considered a clinical component of chronic traumatic encephalopathy.

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Bottom line: try not to eat processed sweetened foods or drink sodas because high intake is linked to type 2 diabetes. Several studies point the finger in particular to high fructose corn syrup, which is the most frequently used sweetener in processed foods, particularly fruit-flavored drinks and soda. An earlier 2013 study from Europe found that drinking one 12-ounce sugar-sweetened soft drink a day can increase the risk of type 2 diabetes by 22%. Instead eat real whole foods like fruits and vegetables. From Medscape:

Added Sweeteners in Processed Foods Tied to Diabetes

A large body of evidence from animal studies and observational and clinical trials in humans suggests that eating processed foods with added sweeteners is contributing to the growing incidence of type 2 diabetes, a new review, published online January 29 in the Mayo Clinic Proceedings, concludes. Thus, "by limiting sugar to 5% to 10% of total caloric intake, the harmful effects of sugar, particularly fructose, on insulin resistance could be minimized," he and his colleagues conclude. This in turn "may protect against diabetes and its complications, including early mortality from cardiovascular causes."

About three-quarters of all packaged foods and beverages in the US contain added sugar, and it is estimated that Americans eat up to 22 to 47 teaspoons of sugar a day, including hidden sugar in processed foods, Dr DiNicolantonio said.

"High intakes of added sugars, especially in the form of sugar-sweetened beverages, are associated with an increased risk of type 2 diabetes." However, at the same time, "people should not be concerned about limiting fructose found in whole foods such as fruits and vegetables," she noted.

The AHA recommends limiting added sugars to no more than 6 tsp (24 g), or 100 calories, per day for women, and 9 tsp (36 g), or 150 calories, per day, for men and cutting sugar-sweetened beverage consumption to no more than 36 ounces, or 450 calories, per week.

From Science Daily:

Added fructose is a principal driver of type 2 diabetes, experts argue

Recent studies have shown that added sugars, particularly those containing fructose, are a principal driver of diabetes and pre-diabetes, even more so than other carbohydrates. Clinical experts challenge current dietary guidelines that allow up to 25 percent of total daily calories as added sugars, and propose drastic reductions in the amount of added sugar, and especially added fructose, people consume.

The totality of the evidence is compelling to suggest that added sugar, and especially added fructose (usually in the form of high-fructose corn syrup and table sugar), are a serious and growing public health problem, according to the authors.

While fructose is found naturally in some whole foods like fruits and vegetables, consuming these foods poses no problem for human health. Indeed, consuming fruits and vegetables is likely protective against diabetes and broader cardiometabolic dysfunction, explained DiNicolantonio and colleagues. The authors propose that dietary guidelines should be modified to encourage individuals to replace processed foods, laden with added sugars and fructose, with whole foods like fruits and vegetables. 

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Very important research looking at some professional football players who started playing tackle football before the age of 12, and comparing them to those who started later. It discusses the issue of whether children should be playing tackle football before the age of 12 - these and other results suggest NOT. Wait till older (or don't play tackle at all).This article came from Boston University through Futurity:

Is This Kid Too Young For Football?

Researchers from Boston University School of Medicine found that former National Football League (NFL) players who participated in tackle football before the age of 12 are more likely to have memory and thinking problems as adults.

The study contradicts conventional wisdom that children’s more plastic brains might recover from injury better than those of adults, and suggests that they may actually be more vulnerable to repeated head impacts, especially if injuries occur during a critical period of growth and development. "

“This is one study, with limitations,” adds study senior author Robert Stern, a professor of neurology, neurosurgery, and anatomy and neurobiology and director of the Alzheimer’s Disease Center’s Clinical Core. “But the findings support the idea that it may not make sense to allow children—at a time when their brain is rapidly developing—to be exposed to repetitive hits to the head.”

In the study, researchers reexamined data from Boston University’s ongoing DETECT(Diagnosing and Evaluating Traumatic Encephalopathy Using Clinical Tests) study, which aims to develop methods of diagnosing chronic traumatic encephalopathy (CTE) during life. CTE is a neurodegenerative disease often found in professional football players, boxers, and other athletes who have a history of repetitive brain trauma. It can currently be diagnosed only by autopsy.

For this latest study, published in the journal Neurology, scientists examined test scores of 42 former NFL players, with an average age of 52, all of whom had experienced memory and thinking problems for at least six months. Half the players had played tackle football before age 12, and half had not. Significantly, the total number of concussions was similar between the two groups.

Researchers found that the players exposed to tackle football before age 12 had greater impairment in mental flexibility, memory, and intelligence—a 20 percent difference in some cases. These findings held up even after statistically removing the effects of the total number of years the participants played football. Both groups scored below average on many of the tests.

Stamm says the researchers were especially surprised by the scores on a reading test called the WRAT-4, which has participants read words of increasing difficulty....The low scores may be significant, she says, because they suggest that repeated head trauma at a young age might limit peak intelligence. She emphasizes, however, that there may be other reasons for a low score, and that more research is needed.

The authors chose age 12 as the cutoff because significant peaks in brain development occur in boys around that age. (This happens for girls a bit earlier, on average.) Around age 12, says Stern, blood flow to the brain increases, and brain structures such as the hippocampus, which is critical for memory, reach their highest volume.

Boys’ brains also reach a peak in their rate of myelination—the process in which the long tendrils of brain cells are coated with a fatty sheath, allowing neurons to communicate quickly and efficiently. Because of these developmental changes, Stern says, this age may possibly represent a “window of vulnerability,” when the brain may be especially sensitive to repeated trauma.

Stern adds that a study by another group of researchers of the number and severity of hits in football players aged 9 to 12, using accelerometers in helmets, found that players received an average of 240 high-magnitude hits per season, sometimes with a force similar to that experienced by high school and college players.

With approximately 4.8 million athletes playing youth football in the United States, the long-term consequences of brain injury represent a growing public health concern. This study comes at a time of increasing awareness of the dangers of concussions—and subconcussive hits—in youth sports like football, hockey, and soccer. In 2012, Pop Warner football, the oldest and largest youth football organization in the country, changed its rules to limit contact during practices and banned intentional head-to-head contact. 

“Football has the highest injury rate among team sports,” writes Christopher M. Filley, a fellow with the American Academy of Neurology, in an editorial accompanying the Neurology article. “Given that 70 percent of all football players in the United States are under the age of 14, and every child aged 9 to 12 can be exposed to 240 head impacts during a single football season, a better understanding of how these impacts may affect children’s brains is urgently needed.”

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This study is important because it shows (once again) that spatial skills may be developed by what a child does in childhood. The trend for girls to only be given dolls or stereotypically "girl" toys is not that good for mental development (but good for nurturing). All children need to play with blocks, puzzles, and to create and build. They all need to go out and actively explore their environment, which also is good for developing spatial reasoning skills (as shown by earlier research). Think about it: when you actively explore the streets and land around you, you develop "mental maps" of how to get around, and this is good for spatial skills. Bottom line: encourage both boys and girls to build, create, do puzzles, play board games, and explore their outside environment. From Science Daily:

Playing with puzzles, blocks may build children's spatial skills

Play may seem like fun and games, but new research shows that specific kinds of play are actually associated with development of particular cognitive skills. Data from an American nationally representative study show that children who play frequently with puzzles, blocks, and board games tend to have better spatial reasoning ability.

"Our findings show that spatial play specifically is related to children's spatial reasoning skills," says psychological scientist and lead researcher Jamie Jirout of Rhodes College. "This is important because providing children with access to spatial play experiences could be a very easy way to boost spatial development, especially for children who typically have lower performance, such as girls and children from lower-income households."

Being able to reason about space, and how to manipulate objects in space, is a critical part of everyday life, helping us to navigate a busy street, put together a piece of "some assembly required" furniture, even load the dishwasher. And these skills are especially important for success in particular academic and professional domains, including science, technology, engineering, and math (STEM).

Jirout and Newcombe analyzed data from 847 children, ages 4 to 7, who had taken the revised WPPSI [Wechsler Preschool and Primary Scale of Intelligence], which included measures of cognitive skills that contribute to general intelligence. The children's spatial ability was specifically measured via the commonly-used Block Design subtest of the WPPSI, in which children are asked to reproduce specific 2D designs using cubes that have red, white, and half-red/half-white faces. The researchers also examined survey data from parents about the children's play behavior and joint parent-child activities.

The data revealed that family socioeconomic status, gender, and general intelligence scores were all associated with children's performance on the block design task. Children from the low-socioeconomic status group tended to have lower block design scores compared to children from either the middle- or high-socioeconomic status groups. And boys tended to have higher block design scores than did girls, though only after several other cognitive abilities, such as vocabulary, working memory, and processing speed, were taken into account.

Importantly, how often children played with certain toys was also tied to their spatial reasoning skills. Children who played with puzzles, blocks, and board games often (more than six times per week) had higher block design scores than did children who played with them sometimes (three to five times per week), or rarely/never.

None of the other types of play (e.g., drawing, playing with noise-making toys, and riding a bicycle, skateboard, or scooter) or the parent-child activities (e.g., teaching number skills, teaching shapes, playing math games, telling stories) included in the survey data were associated with children's spatial ability.

In line with previous findings, parents reported that boys engaged in spatial play -- playing with puzzles, blocks, and board games -- more often than girls, even after spatial ability was taken into account.

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It's interesting how drinking alcohol seems to have a J-curve for health effects. Light drinkers seem to do the best, but heavy drinkers do the worst of all groups (also see earlier posts). This research (published this week in the journal Stroke) shows that drinking more than 2 drinks a day in middle age is a bigger risk factor (double the risk) for a stroke between the ages of 60 to 75 years than high blood pressure, diabetes, or genetics. And once again, looking at the study one can see that nondrinkers had a small increased risk for stroke vs very light drinkers. From Science Daily:

Heavy drinking in middle-age may increase stroke risk more than traditional factors

Drinking more than two alcoholic beverages a day in middle-age raised stroke risks more than traditional factors such as high blood pressure and diabetes. Heavy drinking in mid-life was linked to having a stroke about five years earlier in life irrespective of genetic and early-life factors.

In a study of 11,644 middle-aged Swedish twins who were followed for 43 years, researchers compared the effects of an average of more than two drinks daily ("heavy drinking") to less than half a drink daily ("light drinking").

The study showed that: - Heavy drinkers had about a 34 percent higher risk of stroke compared to light drinkers. - Mid-life heavy drinkers (in their 50s and 60s) were likely to have a stroke five years earlier in life irrespective of genetic and early-life factors. - Heavy drinkers had increased stroke risk in their mid-life compared to well-known risk factors like high blood pressure and diabetes. - At around age 75, blood pressure and diabetes appeared to take over as one of the main influences on having a stroke.

Researchers analyzed results from the Swedish Twin Registry of same-sex twins who answered questionnaires in 1967-70. All twins were under age 60 at the start. By 2010, the registry yielded 43 years of follow-up, including hospital discharge and cause of death data. ... Almost 30 percent of participants had a stroke. They were categorized as light, moderate, heavy or non-drinkers based on the questionnaires. 

Among identical twin pairs, siblings who had a stroke drank more than their siblings who hadn't had a stroke, suggesting that mid-life drinking raises stroke risks regardless of genetics and early lifestyle.

The study is consistent with the American Heart Association's recommended limit of two drinks a day for men and one for women. That's about 8 ounces of wine (two drinks) for a man and 4 ounces (one drink) for a woman. Regular heavy drinking of any kind of alcohol can raise blood pressure and cause heart failure or irregular heartbeats over time with repeated drinking, in addition to stroke and other risks.

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This is great to hear for those younger and wondering about life for those in their 70s and 80s. A total of 6,201 people between 50 and 90 years old were surveyed in this study.From Science Daily:

Love and intimacy in later life: Active sex lives common in the over 70s

Older people are continuing to enjoy active sex lives well into their seventies and eighties, according to new research. More than half (54%) of men and almost a third (31%) of women over the age of 70 reported they were still sexually active, with a third of these men and women having frequent sex -- meaning at least twice a month -- according to data from the latest wave of the English Longitudinal Study of Ageing (ELSA).

It is the first study on sexual health of its kind to include people over the age of 80 and uncovers a detailed picture of the sex lives of older men and women in England, finding that a sizeable minority remain sexually active in their old age. Contrary to popular misconceptions, it finds that overall health and conflicting partnership factors were more closely linked to decreasing sexual activity and functioning, rather than simply increasing age.

Problems most frequently reported by sexually active women related to becoming sexually aroused (32%) and achieving orgasm (27%), while for men it was erectile difficulties (39%).

Chronic health conditions and poor self-rated health seemed to have more obvious negative impacts on the sexual health of men compared to women.Men were more concerned about their sexual activities and function than women and, with increasing age, these concerns tended to become more common. Sexually active women were less dissatisfied with their overall sex lives than men, and also reported decreasing levels of dissatisfaction with increasing age.

The study also found that many septuagenarians and octogenarians were still affectionate towards their partners, with 31% of men and 20% of women reporting frequent kissing or petting. Among those who reported any sexual activity in the past three months, 1% of men and 10% of women reported they felt obligated to have sex.

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Think about all the plastics we use, and all the chemicals we are exposed to. Read labels on personal care products and try to avoid: phthalates, parabens, BPA, triclosan, fragrances. If possible, use glass containers to store and microwave food. Avoid unnecessary pesticides, for example on lawns, and consider organic lawn care and gardening.  From Science Daily:

Earlier menopause linked to everyday chemical exposures

Women whose bodies have high levels of chemicals found in plastics, personal-care products, common household items and the environment experience menopause two to four years earlier than women with lower levels of these chemicals, according to a new study at Washington University School of Medicine in St. Louis.

The researchers looked at levels in blood and urine of 111 chemicals that are suspected of interfering with the natural production and distribution of hormones in the body. While several smaller studies have examined the link between so-called endocrine-disrupting chemicals and menopause, the new research is the first to broadly explore the association between menopause and individual chemicals on a large scale, using a nationally representative sample of patients across the United States.

“Chemicals linked to earlier menopause may lead to an early decline in ovarian function, and our results suggest we as a society should be concerned,” said senior author Amber Cooper, MD, an assistant professor of obstetrics and gynecology. A decline in ovarian function not only can adversely affect fertility but also can lead to earlier development of heart disease, osteoporosis and other health problems. Other problems already linked to the chemicals include certain cancers, metabolic syndrome and, in younger females, early puberty.

“Many of these chemical exposures are beyond our control because they are in the soil, water and air,” Cooper said. “But we can educate ourselves about our day-to-day chemical exposures and become more aware of the plastics and other household products we use.”...Although many of the chemicals included in the study have been banned from U.S. production because of their negative health effects, they still are produced globally and are pervasive in the environment.

In the study, Cooper and researchers at the University of Missouri-Kansas City School of Medicine and the Wadsworth Center at the State University of New York at Albany analyzed data collected from 1999-2008 as part of the National Health and Nutrition Examination Survey, conducted by the U.S. Centers for Disease Control and Prevention.The survey included data from 31,575 people, including 1,442 menopausal women who had been tested for levels of endocrine-disrupting chemicals. The average age of these women was 61, and none was using estrogen-replacement therapies or had had surgery to remove ovaries.

The women’s blood and urine samples were analyzed for exposures to 111 mostly man-made chemicals, which included known reproductive toxins and/or those that take more than a year to break down. Chemicals from the following categories were analyzed in the survey: dioxins/furans (industrial combustion byproducts); phthalates (found in plastics, common household items, pharmaceuticals and personal-care products including lotions, perfumes, makeup, nail polish, liquid soap and hair spray); phytoestrogens (plant-derived estrogens); polychlorinated biphenyls (PCBs, coolants); phenolic derivatives (phenols, industrial pollutants); organophosphate pesticides; surfactants; and polycyclic aromatic hydrocarbons (combustion products).

The researchers identified 15 chemicals — nine PCBs, three pesticides, two phthalates and a furan (a toxic chemical) — that warrant closer evaluation because they were significantly associated with earlier ages of menopause and potentially have detrimental effects on ovarian functionagefurans

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An amazing breakthrough for those suffering from peanut allergies. The bacteria Lactobacillus rhamnosus is added to some yogurts and kefir, but in smaller amounts.From The Telegraph:

Fatal peanut allergies could be cured by probiotic bacteria, say Australian doctors

A strain of probiotic bacteria could offer a cure for potentially fatal peanut allergies, according to scientists in Australia. The breakthrough followed a trial in which a group of children were given increasing amounts of peanut flour, along with a probiotic called Lactobacillus rhamnosus, over an 18-month period. About 80 per cent of the children who had peanut allergies were subsequently able to tolerate peanuts.

Mimi Tang, the lead researcher, said the families involved believed the treatment had "changed their lives". "These findings provide the vital first step towards developing a cure for peanut allergy and possibly for all food allergies," she told Melbourne's Herald Sun.

The randomised trial, involving a group of about 30 children, was conducted by Murdoch Childrens Research Institute in Melbourne. The children, aged one to ten, were given small amounts of peanut flour, gradually building up to two grams, or the equivalent of six or seven nuts.They were also given daily doses of Lactobacillus rhamnosus, which is found in yoghurt but was given in quantities equivalent to the amount found in 44 pounds of yoghurt.

Following the treatment, about 80 per cent of the children were able to tolerate four grams of peanut protein, equivalent to about 14 peanuts. Typically, about four per cent of children would have overcome their peanut allergy during this time.

Rates of peanut allergies have dramatically increased in the past two decades, particularly in developed countries. For most sufferers, the condition is lifelong.

A link to the press release from the Murdoch Childrens Research Institute (their researchers are doing the research), has more:

Oral Therapy Could Provide Treatment For Peanut Allergies

Over 60 peanut allergic children in the study were either given a dose of a probiotic, Lactobacillus rhamnosus, together with peanut protein in increasing amounts, or a placebo over 18 months to assess whether children would become tolerant to peanut.

The probiotic was a fixed daily dose, while the peanut oral immunotherapy was a daily dose of peanut protein starting at very low doses followed by a dose increase every two weeks until the maintenance dose (2 grams peanut protein) was reached. At the end of the treatment, the child's ability to tolerate peanut was assessed by a peanut challenge performed two to five weeks after stopping treatment.

23 of 28 (82.1%) probiotic treated children and one of 28 (3.6%) placebo-treated children were able to include peanut in their diet at the end of the trial. The likelihood of success was high - if nine children were given probiotic and peanut therapy, seven would benefit.

The need for a curative treatment is greatest for peanut allergy since this is usually lifelong, and is the most common cause of fatality due to food induced anaphylaxis. Further research is now required to confirm whether patients can still tolerate peanut years after the study has finished.

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This is so sad, but it's the new reality in the USA. Less discussed, but also problematic is the increase in early puberty in boys.The research as to causes is ongoing, but increasingly our exposure to chemicals, especially endocrine disruptors is suspected to be a cause. What to do? Once again: try to reduce exposure to plastics (ha!) by buying and storing food in glass containers, and do not microwave food in plastic containers. Avoid fragrances or perfumed products. From Newsweek:

Puberty Comes Earlier and Earlier for Girls

At age 6, Rebecca’s body began to develop in ways that seemed unusual. Her mother, Ellen, had noticed a change in Rebecca’s breast area...But there was also the hair that had begun to appear under her daughter’s arms. When a test showed Rebecca’s bone age to be 10½, a pediatric endocrinologist diagnosed “precocious puberty.” While the exact cause is unknown, this endocrine disorder is triggered by the early release of hormones in the brain, a circumstance that hurls a child into sexual maturation years before the usual age.

This sudden sexual development in a child so young can be unnerving to parents. “My daughter is 7 years and 10 months old. She started having body odor at 5 and breast buds at 6,” one mother wrote recently in a group chat about the condition. She wrote, too, of her daughter’s “roller-coaster emotions,” a common complaint from parents observing massive mood swings, PMS-like symptoms and other “teen emotions” in daughters just beginning the first grade—and in some cases even younger. The condition affects individuals in different ways. ”...Unlike Rebecca, many precocious kids lose their interest in Disney and little-girl things and begin to act, well, the age of their bodies.

In girls, puberty is commonly defined as breast development, growth of pubic hair and menarche, the beginning of the menstrual cycle. At the turn of the 20th century, the average age for an American girl to get her period was 16 to 17. Today, that number has plummeted to less than 13, according to data from the National Health and Nutrition Examination Survey. The trend has been attributed to the epidemic of overweight children and a greater exposure to pollution, which does bad things to developing bodies and accelerates the timing of a girl’s first menstruation.

Environmental toxins also cause many girls to develop breasts at an earlier age than in the past. Compared with 20 years ago, American girls today begin developing breasts anywhere from one month to four months earlier, a significant difference. At the same time, the number of girls who begin to develop early is increasing. “Just a generation ago, less than five percent of girls started puberty before the age of 8; today that percentage has more than doubled,” note Dr. Louise Greenspan and Dr. Julianna Deardorff in The New Puberty: How to Navigate Early Development in Today’s Girls.

Among the toxins causing this trend, the biggest offenders are plastic compounds, in particular phthalates, man-made chemicals found all over the place: in plastic food and beverage containers, carpeting, shampoos, insect repellents, vinyl flooring, shower curtains, plastic toys and in the steering wheels and dashboards of most cars. Our bodies cannot metabolize phthalates, which interfere with the endocrine system—the body’s system of glands and hormones—and harm fat cells. Indirectly, phthalates may cause weight gain and so influence the timing of puberty. 

Our children are living in a “sea of chemicals,” says Dr. Marcia E. Herman-Giddens, a professor of public health at the University of North Carolina. She argues that children are speeding into puberty before they’re ready, and that this early maturation is both the symptom of bodily damage that has already occurred and the probable cause of health consequences they may expect in the future.

Along with higher rates of depression, younger girls who enter puberty earlier than their peers are more prone to obesity and drug abuse...Meanwhile, no matter how physically developed a girl is, her psychosocial maturation remains anchored to her chronological age. 

“Puberty is considered one of those windows of susceptibility,” says Biro, when the body is especially sensitive to the negative health impact of social and environmental stressors. In particular, the actively maturing breast tissue of a girl, unlike the breast tissue of a full-grown woman, is more vulnerable to damaging environmental pollutants.

Today’s girl is both starting puberty earlier and going through it more slowly, according to Biro, which means a girl remains in this high-risk state for a longer amount of time. In an article he co-authored with Deardorff and others, Biro found up to a 30 percent increased risk for breast cancer when a woman experiences her first period at a younger age. And “for each year that age of menarche was delayed, the risk of premenopausal breast cancer was reduced by 9 percent, and risk of postmenopausal breast cancer was reduced by 4 percent.”

Early breast development also opens the door to reproductive tract cancers, says Herman-Giddens, since “if you’re starting to develop breasts, your body is making estrogen.” Estrogen, especially when combined with stress hormones, is a known cancer-causing agent. Having had an earlier start to puberty, an early-maturing girl produces more estrogen over the years and so elevates her lifetime risk of reproductive cancers.

There is a medical solution for patients who, like 6-year-old Rebecca, are diagnosed with precocious puberty. Hormone treatments can essentially halt the process of sexual maturation. Then, at an appropriate age, the drugs are withdrawn and puberty plays out.Some girls diagnosed with precocious puberty have no choice but to medicate in order to prevent serious bone and growth problems.