Latest news with #UniversityofWashington
Yahoo
20 hours ago
- Health
- Yahoo
Humans used to have straighter teeth—what changed?
Braces, rubber bands, even jaw surgery—millions endure them in pursuit of a straighter smile. But were misaligned smiles always this common? Research suggests that might not be the case. While malocclusions—crowded or misaligned teeth—have been found among our hunter-gatherer ancestors, they appear to be more prevalent in modern populations. So what changed? Experts say the answer isn't simple but point to one possible culprit: our diets. As we traded raw, tough foods for softer, more processed ones, the burden of chewing decreased, allowing our jaws to shrink over time. Now, researchers are exploring how evolutionary biology, diet, and modern lifestyles may have reshaped our faces—and our smiles. Ancient human skulls were strikingly different from our own. Early hunter-gatherers had large, powerful jaws built for the demanding work of chewing tough meats, fibrous vegetables, seeds, and nuts. But around 12,000 years ago, things began to change. As humans around the world traded hunting for farming, their diets changed too, incorporating more grains and cultivated produce into their diet. These foods were softer, more processed, and required far less chewing.' We did not have ice cream or white bread back in the day,' says Sue Herring, professor emeritus in orthodontics at the University of Washington. 'When you get your food straight from the environment, it's probably a little [grittier] than stuff which has been cooked and processed.' (Neanderthal teeth reveal intimate details of daily life.) With softer diets came less mechanical strain on the jaw. Over generations, our mandibles began to shrink— a trend visible in the fossil record. That shrinkage is, at least in part, adaptive and the result of millennia of evolution, says Myra Laird, assistant professor of basic and translational sciences at the University of Pennsylvania School of Dental Medicine. 'If you don't need a huge mandible, it's energetically costly to build that extra bone.' But not all changes in jaw size and shape are evolutionary. Bone is highly responsive to physical stress—even within a single lifetime—and builds up around muscle attachment sites. In other words, less muscle usage results in less robust bones, Laird says, citing studies of craniofacial growth in non-human animals like hyraxes. 'If you switch to a liquid diet, you will not use your muscles as much and see some shape changes in your face.' (Here's how ultra-processed food harms the body and brain.) That's exactly what researchers believe happened to humans as they adopted agriculture. 'Post-agricultural populations had a marked reduction in the size of the chewing muscles,' Laird says. 'What this suggests is that the origins of agriculture brought about less work for the feeding system'—and, ultimately, much less roomy mouths. So, what happens when you try to fit the same number of teeth into a smaller jaw space? Over-crowding and crookedness. 'The way your teeth come through is almost like a zipper,' says Julie Lawrence, assistant professor of biological anthropology at the University of Nevada, Las Vegas. 'Your jaw moves forward and then it makes space for them to come through.' If there isn't enough room for the teeth to erupt, they might become impacted or crowded together. The third molars, or wisdom teeth, are particularly at risk for noneruption in undersized jaws. Research suggests that the mismatch between the size of the mandible and dentition may be to blame for increasingly crooked teeth among post-industrial humans. 'That loss of space is really what precipitates the malocclusions, dental crowding,' says Laird. 'The rate of malocclusion goes way, way up [in modern humans], and that is ubiquitous across all populations.' (Why we add fluoride to water—and how it became so controversial.) But experts caution that the story isn't so simple. Although the frequency of malocclusions seems to have increased among modern humans, dental impaction and crowding have been observed in early hominid skulls. The fossil record is limited and likely not fully representative, Lawrence says. 'Better teeth tend to be better preserved,' she says, adding that anthropological data doesn't take into account confounding factors like missing teeth. While 'there does seem to be a pattern' of increased malocclusions among post-industrialization humans, Lawrence adds, not all changes in teeth alignment can be attributed to diet. Extreme under- or overbite, for example, is the result of population genetics and 'doesn't have to do with industrialization.' Many other factors can cause crooked teeth, including environmental conditions or developmental anomalies. And some populations are more genetically predisposed to malocclusions. Ultimately, the prevalence of crooked teeth may also be due in small part to aesthetic bias. 'Our modern society is a lot more sensitive to cosmetic problems,' Herring says. 'I think we're a lot more aware of malocclusions now than anybody was in the past.'
Medscape
2 days ago
- Health
- Medscape
Tocilizumab Delays: A Barrier in Giant Cell Arteritis Care?
TOPLINE: Patients with giant cell arteritis started tocilizumab therapy an average of 43 days after diagnosis, partly because of delays in insurance approval. METHODOLOGY: Overall, 82 patients (average age, 73 years; 60% women; 87% White individuals) newly diagnosed with giant cell arteritis at the University of Washington, Seattle, Washington, between November 2017 and August 2024 were prescribed 162 mg of subcutaneous tocilizumab. Data on demographics, insurance type, and detailed timelines for medication request, approval, and initiation were collected. When available, cost data for tocilizumab were obtained from insurance quotes, along with information on prior authorization requirements, copay assistance, and medication coverage. The time from the initial tocilizumab request to insurance approval and medication start was analyzed, and costs by insurance payer were compared. TAKEAWAY: Delays in approval for and administration of tocilizumab therapy for newly diagnosed giant cell arteritis increase the risk for vision loss, glucocorticoid exposure, and side effects. The average time from tocilizumab request to the start of treatment was 43 days; from request to insurance approval, 17 days; and from approval to medication start, 30 days. Out-of-pocket costs for tocilizumab averaged $1399 for Medicare patients, $823 for those with Medicare Advantage, $211 for those with commercial insurance, and $0 for Medicaid (P < .01). Commercially insured patients used copay cards more often than other payers (P < .01); Medicare or Medicare Advantage patients had a higher utilization of medication coverage from drug manufacturers (P = .04). IN PRACTICE: 'During the study period, there was only one FDA-approved medication for GCA [giant cell arteritis], yet the high cost and delays to medication start remained high. Understanding the delays, costs, and factors that prevent timely therapy is critical to rheumatologic and geriatric care,' the authors of the study wrote. '[T]he results offer important insights into the administrative and financial frustrations related to securing biologic approval and coverage, which has been documented in other conditions,' experts wrote in an editorial. SOURCE: This study was led by Dominique Feterman Jimenez, MD, University of Washington, Seattle. It was published online on March 15, 2025, in The Journal of Rheumatology. LIMITATIONS: The single-center design may limit the generalizability of the findings beyond Washington State because insurance plans vary by state. The predominance of patients with Medicare may also limit applicability of the findings. The small sample size restricted the ability to analyze differences among various Medicare supplemental plans. DISCLOSURES: One author disclosed receiving support from a Rheumatology Research Foundation Investigator Award. The authors declared having no conflicts of interest. This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.
Business Insider
3 days ago
- Business
- Business Insider
Former Amazon principal engineer says he spent '1-4 hours' reading daily — and it's part of the company's 'secret sauce'
When Steve Huynh was a principal engineer at Amazon, meetings began with a "study hall." Amazon had a "reading culture" even among engineers, Huynh recently told the Pragmatic Engineer podcast, speaking of his time at the tech giant. Employees frequently drafted six-page memos, he said, which they shared with the company to update progress and demonstrate new projects. "I spent on the order of like 1-4 hours every day reading while I was a principal engineer," Huynh said. "What an amazing culture that I think that almost every other company should replicate if they could." Huynh, who said the company's embrace of writing and reading the 6-page memos was part of its "secret sauce," said Amazon employees' writing was often constrained to the format during his tenure at the company, whether it was a business strategy, system design, or press release. Huynh started at Amazon in 2006, only a few years after the company turned its first profit and while Jeff Bezos was at the helm. Bezos famously instilled this culture of memo-writing from the top down. Bezos insisted on dense, direct memos in 10-point font. In his 2017 letter to shareholders, Bezos wrote that "we don't do PowerPoint," instead opting for these six-pagers. "Not surprisingly, the quality of these memos varies widely," he wrote. Before meetings, Amazon employees read these memos together. On the Lex Fridman Podcast in 2023, Bezos explained why he didn't ask employees to read the memos in advance. "The problem is people don't have time to do that, and they end up coming to the meeting having only skimmed the memo, or maybe not read it at all," Bezos said. "They're also bluffing like they're in college, having pretended to do the reading." Andy Jassy, Bezos' successor and Amazon's current CEO, has worked at the company since 1997. When first pitching what would become Amazon Web Services, Jassy described writing his own memo. "I remember this six-page narrative, we called it a vision doc. We asked for 57 people, which felt so ballsy at the time. I was so nervous, I wrote 30 drafts of this paper, and Jeff didn't blink," Jassy said in a 2017 talk to the University of Washington. Jassy has continued the culture of memo-writing under his own leadership. In his 2024 letter to shareholders, Jassy wrote that a mere six-page allotment made the memos "much easier for the audience to engage with and ask the right 'why' questions." "I got really really good at just reading these documents to get up to speed," Huynh said on the podcast, explaining that reading enough six-page memos taught him to express himself in the same format. Huynh no longer works at Amazon. He left to pursue YouTube content creation full-time, as he told BI in 2024. But Huynh still reveres the company's reading culture — even if he acknowledges it may not be easily reproducible. "The difficulty would be, you actually have to be disciplined and principled," Huynh said. His interviewer, Gergely Orosz, argued it could only be done from the top down. Huynh agreed.
Irish Daily Mirror
5 days ago
- Health
- Irish Daily Mirror
Warning issued to anyone who eats hot dogs or burgers as barbecue season arrives
The hot weather returned to Ireland this week and, as such, many will be planning a barbecue this weekend because so far this summer, the rain has never been too far away. With people stocking up on burgers and hot dogs, a warning has been issued by scientists on the dangers of processed meats. The Express reports that US researchers have released the findings of a new project which saw them review over 70 previous studies, comprising millions of participants. The research examined the link between processed meat and a wide range of illnesses including Type 2 diabetes, cancer and ischemic heart disease. The study found that even the smallest portion of processed meats was the worst addition to a person's diet, even compared to trans fats and sugary drinks. The University of Washington team wrote in their paper: "The monotonic increases in health risk with increased consumption of processed meat suggest that there is not a 'safe' amount of processed meat consumption with respect to diabetes or colorectal cancer risk. "Habitual consumption of even small amounts of processed meat, sugary drinks, and trans fatty acids is linked to increased risk of developing type 2 diabetes, ischemic heart disease and colorectal cancer." The equivalent of one hot dog a day was associated with at least an 11 per cent higher risk of Type 2 diabetes, and a 7 per cent higher risk of colorectal cancer compared to eating no meat at all. Ireland's Health Service Executive (HSE) has advised to "Avoid processed meat and limit red meat to no more than 3 portions a week to lower your risk of bowel cancer." The research found that even one hot dog a day may be too high, with the authors explaining in Nature that more examination is required but that there is a "merit" to limiting consumption. They wrote: "These associations each received two-star ratings reflecting weak relationships or inconsistent input evidence, highlighting both the need for further research and—given the high burden of these chronic diseases—the merit of continuing to recommend limiting consumption of these foods."
Yahoo
5 days ago
- Science
- Yahoo
Expired Cans of Salmon From Decades Ago Contained a Huge Surprise
Canned salmon are the unlikely heroes of an accidental back-of-the-pantry natural history museum – preserving decades of Alaskan marine ecology in brine and tin. Parasites can reveal a lot about an ecosystem, since they tend to get up in the business of multiple species. But unless they cause a major issue for humans, historically we've mostly ignored them. That's a problem for parasite ecologists, like Natalie Mastick and Chelsea Wood from the University of Washington, who had been searching for a way to retroactively track the effects of parasites on Pacific Northwestern marine mammals. So when Wood got a call from Seattle's Seafood Products Association, asking if she'd take boxes of dusty old expired cans of salmon – some dating back to the 1970s – off their hands, her answer was, unequivocally, yes. Related: The cans had been set aside for decades as part of the association's quality control process, but in the hands of the ecologists, they became an archive of excellently preserved specimens; not of salmon, but of worms. While the idea of worms in your canned fish is a bit stomach-turning, these roughly 0.4-inch (1-centimeter) long marine parasites, anisakids, are harmless to humans when killed during the canning process. "Everyone assumes that worms in your salmon is a sign that things have gone awry," said Wood when the research was published last year. "But the anisakid life cycle integrates many components of the food web. I see their presence as a signal that the fish on your plate came from a healthy ecosystem." Anisakids enter the food web when they are eaten by krill, which in turn are eaten by larger species. This is how anisakids end up in the salmon, and eventually, the intestines of marine mammals, where the worms complete their life cycle by reproducing. Their eggs are excreted into the ocean by the mammal, and the cycle begins again. "If a host is not present – marine mammals, for example – anisakids can't complete their life cycle and their numbers will drop," said Wood, the paper's senior author. The 178 tin cans in the 'archive' contained four different salmon species caught in the Gulf of Alaska and Bristol Bay across a 42-year period (1979–2021), including 42 cans of chum (Oncorhynchus keta), 22 coho (Oncorhynchus kisutch), 62 pink (Oncorhynchus gorbuscha), and 52 sockeye (Oncorhynchus nerka). Although the techniques used to preserve the salmon do not, thankfully, keep the worms in pristine condition, the researchers were able to dissect the filets and calculate the number of worms per gram of salmon. They found worms had increased over time in chum and pink salmon, but not in sockeye or coho. "Seeing their numbers rise over time, as we did with pink and chum salmon, indicates that these parasites were able to find all the right hosts and reproduce," said Mastick, the paper's lead author. "That could indicate a stable or recovering ecosystem, with enough of the right hosts for anisakids." But it's harder to explain the stable levels of worms in coho and sockeye, especially since the canning process made it difficult to identify the specific species of anisakid. "Though we are confident in our identification to the family level, we could not identify the [anisakids] we detected at the species level," the authors write. "So it is possible that parasites of an increasing species tend to infect pink and chum salmon, while parasites of a stable species tend to infect coho and sockeye." Mastick and colleagues think this novel approach – dusty old cans turned ecological archive – could fuel many more scientific discoveries. It seems they've opened quite a can of worms. This research was published in Ecology and Evolution. An earlier version of this article was published in April 2024. Melting Glaciers Could Reawaken Hundreds of Earth's Volcanoes Blue Sharks May Be Secret Chameleons, Scientists Discover Scientists Just Debunked 'Earth's Oldest Impact Crater'
