Science! (4 Viewers)

 
The age when girls hit puberty has been falling at an alarming rate for decades, and scientists have struggled to explain why. New research suggests a compound found in a wide variety of products — from cosmetics to air fresheners to detergents and soaps — may send a signal to an area of the brain that triggers the start of puberty.

It’s the first time researchers have looked at the possible impact of environmental chemicals on the brain to explain the rise in early puberty, said Dr. Natalie Shaw, a pediatric endocrinologist at the National Institute of Environmental Health Sciences in Durham, North Carolina.

Starting puberty significantly early — younger than age 8 in girls, 9 in boys — may have health effects lasting into adulthood, including higher risks of breast cancer, diabetes and heart disease. It can also lead to shortened stature in both girls and boys. In May, a study from the Harvard T.H. Chan School of Public Health found that 15.5% of girls experienced early periods — younger than age 11 — and that 1.4% started menstruating younger than age 9.

Previously, scientists have suggested possible causes including obesity, diet, socioeconomic status and potential exposure to substances such as phthalates that can disrupt sex hormones.

Shaw, a co-senior author of the new study, acknowledged a link between early puberty and excess weight in young girls. “I do think it plays a role, but in my practice, it’s not just those who are overweight or obese who are having early puberty,” she said.

While the timing of puberty may depend at least partly on genetics, a rapid change points “100% to environmental factors,” Shaw said. That’s what led the researchers to search for a compound that children might commonly be exposed to.

If Shaw and her team have found a compound that might affect when the brain sends the signal to begin puberty, they will also have discovered the mechanism at the root of the change in timing, which population studies haven’t been able to do.

Combing through 10,000 compounds in a library of licensed pharmaceuticals, environmental chemicals and dietary supplements, the researchers found several that might influence the timing of puberty. But children were most likely to be exposed to only one of them: musk ambrette, according to the report, published in Endocrinology.

Musk ambrette, a synthetic form of the fragrance, could latch onto a puberty-related receptor in the hypothalamus, which would lead to the release of GnRH, a hormone involved in the maturation of sexual organs and the production of estrogen, testosterone and progesterone.

Musk ambrette is widely used in inexpensive or counterfeit fragrances and other scented personal care products, Shaw said. But it has also turned up in surveys of wastewater and in the bodies of freshwater fish, the researchers noted.……

 
Pigeon-guided missiles, rats and pigs breathing through their anuses, dead trouts that can swim, and drunk worms are among the unusual scientific breakthroughs that make up the winners of this years Ig Nobels.

Ten prizes were awarded on Thursday in a range of scientific categories to individuals and teams from around the world for research that spanned the decades…….



 
Pigeon-guided missiles, rats and pigs breathing through their anuses, dead trouts that can swim, and drunk worms are among the unusual scientific breakthroughs that make up the winners of this years Ig Nobels.

Ten prizes were awarded on Thursday in a range of scientific categories to individuals and teams from around the world for research that spanned the decades…….



There was a pigeon bomb developed in WW2 that would have worked but it was decided not to use it.

 
Profound changes that sweep across the human brain during pregnancy have been captured for the first time, after researchers performed precision scans on a woman carrying her child.

MRI scans taken every few weeks from before conception until two years after childbirth revealed widespread reorganisation in the mother’s brain, with some changes short-lived and others lasting years.

The work, described as “truly heroic” by one independent expert, paves the way for a far deeper understanding of the mother’s brain in pregnancy. Further scans are now being gathered from other pregnant women to learn about the risks of postnatal depression, the link between pre-eclampsia and dementia, and why pregnancy can reduce migraines and symptoms of multiple sclerosis.


Scientists took 26 brain scans of a healthy 38-year-old woman who conceived via IVF, and concurrent blood samples to monitor the dramatic surges in hormones during pregnancy. The data revealed how the brain changed, week by week.

Most apparent was a steady decrease in grey matter, the wrinkly outer surface of the brain, throughout pregnancy and a temporary peak in neural connectivity at the end of the second trimester.

“The maternal brain undergoes this choreographed change across gestation and we’re finally able to observe the process in real time,” said Prof Emily Jacobs, a researcher on the study at the University of California, Santa Barbara.

Scientists have previously taken snapshots of women’s brains at various points in pregnancy, but the latest work shows how these can miss temporary changes that revert to normal by the time the woman gives birth.

Writing in Nature Neuroscience, the lead author, Laura Pritschet, and her colleagues describe how soaring hormones, such as oestrogen and progesterone, drive significant physiological changes in pregnancy, affecting blood plasma, metabolism, oxygen consumption and immunity. The same hormones resculpt the brain.…….

 
Superbugs will kill more than 39 million people before 2050 with older people particularly at risk, according to a new global analysis.

While deaths linked to drug resistance are declining among very young children, driven by improvements in vaccination and hygiene, the study found the opposite trend for their grandparents.

By the middle of the century, 1.91 million people a year are forecast to die worldwide directly because of antimicrobial resistance (AMR) – in which bacteria evolve so that the drugs usually used to fight them no longer work – up from 1.14 million in 2021. AMR will play some role in 8.2 million deaths annually, up from 4.71 million.

The study, published in the Lancet was conducted by the Global Research on Antimicrobial Resistance (Gram) Project and is the first global analysis of AMR trends over time……..

 
Shrink-wrap sealed around a piece of raw meat. Takeout containers filled with restaurant leftovers. Plastic bottles filled with soft drinks.


These are just a few types of food packaging that surround humans every day. And a new study released Monday shows the chemical toll of all that wrapping — and how it might affect the human body.


Researchers from Switzerland and other countries discovered that of the roughly 14,000 known chemicals in food packaging, 3,601 — or about 25 percent — have been found in the human body, whether in samples of blood, hair or breast milk.


Those chemicals include metals, volatile organic compounds, per- and polyfluoroalkyl substances or PFAS, phthalates and many others known to disrupt the endocrine system and cause cancer or other diseases.

The study, published in the Journal of Exposure Science and Environmental Epidemiology, didn’t directly examine the link to these illnesses. But the researchers say their inventory of chemicals can help future research into health risks.

“There are known hazardous chemicals that are known to be linked with adverse human health outcomes,” said Jane Muncke, the chief scientific officer of the Food Packaging Forum and one of the paper’s authors.

“And these chemicals leach out of packaging.”

Scientists have known for many years that chemicals can spill out of food packaging into the food itself. How many chemicals — and in what quantities — depends on the type of packaging and the type of food.


High temperatures can cause chemicals to leach more quickly into food, which is why scientists recommend avoiding microwaving food in takeout containers.

Foods that are high in fat or high in acidity also tend to absorb more chemicals from their packaging, as do foods that are tucked into smaller containers — the more cramped the container, the more contact it has with the food inside……..



 

Create an account or login to comment

You must be a member in order to leave a comment

Create account

Create an account on our community. It's easy!

Log in

Already have an account? Log in here.

Users who are viewing this thread

Back
Top Bottom