![\"\"](\"https:\/\/healthrights.mk\/wp-content\/uploads\/2024\/08\/Puberty-May-Start-Earlier.jpg\")
<\/p>\nSome girls are starting to develop breasts as early as age 6 or 7. Researchers are studying the role of obesity, chemicals and stress.<\/p>\n
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Credit…Eleni Kalorkoti<\/em><\/p>\n https:\/\/www.nytimes.com\/2022\/05\/19\/science\/early-puberty-medical-reason.html#:~:text=Girls%20who%20go%20through%20puberty,or%20uterine%20cancer%20in%20adulthood.<\/a><\/p>\n By\u00a0<\/strong>Azeen Ghorayshi<\/strong><\/a><\/p>\n June 22, 2024 – Marcia Herman-Giddens first realized something was changing in young girls in the late 1980s, while she was serving as the director for the child abuse team at Duke University Medical Center in Durham, N.C. During evaluations of girls who had been abused, Dr. Herman-Giddens noticed that many of them had started developing breasts at ages as young as 6 or 7 years.<\/p>\n \u201cThat did not seem right,\u201d said Dr. Herman-Giddens, who is now an adjunct professor at the University of North Carolina Gillings School of Global Public Health. She wondered whether girls with early breast development were more likely to be sexually abused, but she could not find any data keeping track of puberty onset in girls in the United States. So she decided to collect it herself.<\/p>\n A decade later, she published a study of more than\u00a017,000 girls<\/a>\u00a0who underwent physical examinations at pediatricians\u2019 offices across the country. The numbers revealed that, on average, girls in the mid-1990s had started to develop breasts \u2014 typically the first sign of puberty \u2014 around age 10, more than a year earlier than previously recorded. The decline was even more striking in Black girls, who had begun developing breasts, on average, at age 9.<\/p>\n The medical community was shocked by the findings, and many were doubtful about a dramatic new trend spotted by an unknown physician assistant, Dr. Herman-Giddens recalled. \u201cThey were blindsided,\u201d she said.<\/p>\n But the study turned out to be a watershed in the medical understanding of puberty. Studies in the\u00a0decades since<\/a>\u00a0have confirmed, in dozens of countries, that the age of puberty in girls has dropped by about three months per decade since the 1970s. A\u00a0similar pattern<\/a>, though less extreme, has been observed in boys.<\/p>\n Although it is difficult to tease apart cause and effect, earlier puberty may have harmful impacts, especially for girls. Girls who go through puberty early are at a\u00a0higher risk<\/a>\u00a0of depression, anxiety, substance abuse and other psychological problems, compared with peers who hit puberty later. Girls who get their periods earlier may also be at a higher risk of\u00a0developing breast<\/a>\u00a0or\u00a0uterine cancer<\/a>\u00a0in adulthood.<\/p>\n No one knows what risk factor \u2014 or more likely, what combination of factors \u2014 is driving the age decline or why there are stark race- and sex-based differences. Obesity seems to be playing a role, but it cannot fully explain the change. Researchers are also investigating other potential influences, including chemicals found in certain plastics and stress. And for unclear reasons, doctors across the world have reported a rise in early puberty cases during the pandemic.<\/p>\n \u201cWe are seeing these marked changes in all our children, and we don\u2019t know how to prevent it if we wanted to,\u201d said Dr. Anders Juul, a pediatric endocrinologist at the University of Copenhagen who has published two recent studies on the phenomenon. \u201cWe don\u2019t know what is the cause.\u201d<\/em><\/p>\n Obesity<\/strong><\/p>\n Around the time that Dr. Herman-Giddens published her landmark study, Dr. Juul\u2019s research group examined breast development in a cohort of 1,100 girls in Copenhagen. Unlike the American children, the Danish group matched the pattern long described in medical textbooks: Girls began developing breasts at an average age of 11 years old.<\/p>\n \u201cI was interviewed quite a lot about the U.S. puberty boom, as we called it,\u201d said Dr. Juul. \u201cAnd I said, \u2018it\u2019s not happening in Denmark.\u2019\u201d<\/p>\n At the time, Dr. Juul suggested that the earlier onset of puberty in the United States was probably tied to a rise in childhood obesity, which had not occurred in Denmark.<\/p>\n Obesity has been linked to earlier periods in girls\u00a0since the 1970s<\/a>. Numerous\u00a0studies since<\/a>\u00a0have established<\/a>\u00a0that girls who are overweight or\u00a0<\/a>obese\u00a0tend to start<\/a>\u00a0their periods earlier than girls of average weights do.<\/p>\n In one\u00a0decades-long study<\/a>\u00a0of nearly 1,200 girls in Louisiana published in 2003, childhood obesity was linked to earlier periods: Each standard deviation above the average childhood weight was associated with a doubled chance of having a period before age 12.<\/p>\n And in 2021,\u00a0researchers from Britain<\/a>\u00a0found that leptin, a hormone released by fat cells that limits hunger, acted on a part of the brain that also regulated sexual development. Mice and people with certain genetic mutations in this region experienced later sexual development.<\/p>\n \u201cI don\u2019t think there\u2019s much controversy that obesity is a major contributor to early puberty these days,\u201d said Dr. Natalie Shaw, a pediatric endocrinologist at the National Institute of Environmental Health Sciences who\u00a0has studied<\/a>\u00a0the effects of obesity on puberty.<\/p>\n Still, she added, many girls who develop early are not overweight.<\/p>\n \u201cObesity can\u2019t explain all of this,\u201d Dr. Shaw said. \u201cIt\u2019s just happened too quickly.\u201d<\/p>\n Chemicals<\/strong><\/p>\n In the decade after the Herman-Giddens study, Dr. Juul began noticing an increase in the number of referrals for early puberty in Copenhagen, mostly of girls who were developing breasts at 7 or 8 years old.<\/p>\n \u201cAnd then we thought, \u2018Is this a real phenomenon?\u2019\u201d Dr. Juul said. Or, he wondered, had parents and doctors become \u201chysterical\u201d because of the news coverage of Dr. Herman-Giddens\u2019s study?<\/p>\n In a\u00a02009 study<\/a>\u00a0of nearly 1,000 school-aged girls in Copenhagen, his team found that the average age of breast development had dropped by a year since his earlier study, to a little under 10, with most girls ranging from 7 to 12 years old. Girls were also getting their periods earlier, around age 13, about four months earlier than what he had reported before.<\/p>\n \u201cThat\u2019s a very marked change in a very short period of time,\u201d Dr. Juul said.<\/p>\n But, unlike doctors in the United States, he did not think obesity was to blame: The body mass index of the Danish children in the 2009 cohort was no different than it had been in the 1990s.<\/p>\n Dr. Juul has become one of the most vocal proponents of an alternate theory: that chemical exposures are to blame. The girls with the earliest breast development in his 2009 study, he said, had the highest urine levels of phthalates, substances used to make plastics more durable that are found in everything from vinyl flooring to food packaging.<\/p>\n Phthalates belong to a broader class of chemicals called \u201cendocrine disrupters,\u201d which can affect the behavior of hormones and have become ubiquitous in the environment over the past\u00a0several decades<\/a>. But the evidence that they are driving earlier puberty is murky.<\/p>\n In a\u00a0review article<\/a>\u00a0published last month, Dr. Juul and a team of researchers analyzed hundreds of studies looking at endocrine disrupters and their effects on puberty. The methods of the studies varied widely; some were done in boys, others in girls, and they tested for many different chemicals at different ages of exposure. In the end, the analysis included 23 studies that were similar enough to compare, but it was unable to show a clear association between any individual chemical and the age of puberty.<\/p>\n \u201c<\/strong>The big takeaway is that there\u2019s few publications and a paucity of data to explore this question,\u201d said Dr. Russ Hauser, an environmental epidemiologist at the Harvard T.H. Chan School of Public Health and a co-author of the analysis.<\/p>\n That lack of data has led many scientists to be skeptical of the theory, said Dr. Hauser, who recently reported on how\u00a0endocrine disrupters affect puberty in boys<\/a>. \u201cWe don\u2019t have enough data to build a strong case for a specific class of chemicals.\u201d<\/p>\n Credit…Eleni Kalorkoti<\/em><\/p>\n Stress and lifestyle<\/strong><\/p>\n Other factors may also be involved in earlier puberty, at least in girls.\u00a0Sexual abuse<\/a>\u00a0in early childhood has been linked to\u00a0earlier puberty onset<\/a>. Causal arrows are difficult to draw, however. Stress and trauma could prompt earlier development, or, as Dr. Herman-Giddens hypothesized decades ago, girls who physically develop earlier could be more vulnerable to abuse.<\/p>\n Girls whose mothers have a\u00a0history of mood disorders<\/a>\u00a0also seem more likely to reach puberty early, as are girls who do not live with their\u00a0biological fathers<\/a>. Lifestyle factors like a lack of physical activity have also\u00a0been linked to<\/a>\u00a0changes in pubertal timing.<\/p>\n And during the pandemic, pediatric endocrinologists from across the world noticed that referrals were increasing for earlier puberty in girls. A\u00a0study published<\/a>\u00a0in Italy in February showed that 328 girls were referred to five clinics across the country during a seven month period in 2020, compared with 140 during the same period in 2019. (No difference was found in boys.) Anecdotally, the same thing might be happening in\u00a0India, Turkey<\/a>\u00a0and the United States.<\/p>\n \u201cI\u2019ve asked my colleagues around the country and a number of them are saying, yes, we\u2019re seeing a similar trend,\u201d\u00a0<\/em>said Dr. Paul Kaplowitz, a professor emeritus of pediatrics at Children\u2019s National Hospital in Washington. It\u2019s unclear whether the trend was caused by increased stress, a more sedentary lifestyle or parents being in close enough quarters with their children to notice early changes.<\/p>\n Several factors are most likely contributing at once. And many of these issues disproportionately impact lower-income families, which may partly explain the racial differences in puberty onset in the United States, the researchers said.<\/p>\n \u0418\u0437\u0432\u043e\u0440: WUNRN \u2013 02.07.2024<\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" Some girls are starting to develop breasts as early as age 6 or 7. Researchers are studying the role of obesity, chemicals and stress. Credit…Eleni Kalorkoti https:\/\/www.nytimes.com\/2022\/05\/19\/science\/early-puberty-medical-reason.html#:~:text=Girls%20who%20go%20through%20puberty,or%20uterine%20cancer%20in%20adulthood. By\u00a0Azeen Ghorayshi June 22, 2024 – Marcia Herman-Giddens first realized something was changing…<\/p>\n","protected":false},"author":2,"featured_media":2846,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"post_series":[],"class_list":["post-2845","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-vesti","entry","has-media"],"_links":{"self":[{"href":"https:\/\/healthrights.mk\/index.php?rest_route=\/wp\/v2\/posts\/2845","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/healthrights.mk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/healthrights.mk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/healthrights.mk\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/healthrights.mk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2845"}],"version-history":[{"count":2,"href":"https:\/\/healthrights.mk\/index.php?rest_route=\/wp\/v2\/posts\/2845\/revisions"}],"predecessor-version":[{"id":2850,"href":"https:\/\/healthrights.mk\/index.php?rest_route=\/wp\/v2\/posts\/2845\/revisions\/2850"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/healthrights.mk\/index.php?rest_route=\/wp\/v2\/media\/2846"}],"wp:attachment":[{"href":"https:\/\/healthrights.mk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2845"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/healthrights.mk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2845"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/healthrights.mk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2845"},{"taxonomy":"post_series","embeddable":true,"href":"https:\/\/healthrights.mk\/index.php?rest_route=%2Fwp%2Fv2%2Fpost_series&post=2845"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"https:\/\/healthrights.mk\/wp-content\/uploads\/2024\/08\/Puberty-May-Start-1.jpg\")
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