Hundreds of thousands of people worldwide are taking drugs like Ozempic to lose weight. But what do we actually know about them?
Drugs like Ozempic are very effective at helping most people who take them lose weight. Semaglutide (sold as Wegovy and Ozempic) and tirzepatide (sold as Zepbound and Mounjaro) are the most well known in the class of drugs that mimic hormones to reduce feelings of hunger.But does weight come back when you stop using it? The short answer is yes. Stopping tirzepatide and semaglutide will result in weight regain in most people.
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- Scris de: Natasha Yates
Diabetes, weight loss and now heart health: A new family of drugs is changing the way scientists are thinking about obesity — and more uses are on the horizon
Few drugs have achieved the stardom that semaglutide, marketed in the United States as Ozempic or Wegovy, has today. A synthetic, injectable version of an intestinal hormone, it is the flagship of a new category of drugs initially developed for diabetes that rose to fame in the medical and public arena as an effective weapon against obesity. Semaglutide has proved so successful that its manufacturer, the Danish company Novo Nordisk, is unable to keep up with demand.
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- Scris de: Matías A. Loewy
Certain groups of people are at greater risk of not getting enough vitamin D. Here are some of them.
Nutritional science is supposed to chart a course to our healthier selves. But contradictory scientific results and interpretations can muddy the waters — and few nutrients have recently demonstrated that more clearly than vitamin D.
At one point, it seemed that everyone should be taking vitamin D supplements, and that doing so would protect against a whole host of maladies, from bone problems to heart disease and cancer. More recently, new studies appear to have debunked many of those claims.
But a closer look at the research reveals a more nuanced message around vitamin D supplements: They can be key to correcting deficiencies, though people who already have enough — which is most of the American public — are generally unlikely to see benefits from taking large doses. Experts have come to worry about supplement enthusiasts overdosing in the belief that more is better or, at the other extreme, some nutrient-deprived people shunning them altogether.
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- Scris de: Katarina Zimmer
Contrary to the commonly-held view, the brain does not have the ability to rewire itself to compensate for the loss of sight, an amputation or stroke, for example, say scientists from the University of Cambridge and Johns Hopkins University.
So many times, the brain’s ability to rewire has been described as ‘miraculous’ – but we’re scientists, we don’t believe in magic. Tamar Makin
Writing in eLife, Professors Tamar Makin (Cambridge) and John Krakauer (Johns Hopkins) argue that the notion that the brain, in response to injury or deficit, can reorganise itself and repurpose particular regions for new functions, is fundamentally flawed – despite being commonly cited in scientific textbooks. Instead, they argue that what is occurring is merely the brain being trained to utilise already existing, but latent, abilities.
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- Scris de: Craig Brierley
Hedgerows in mid-February might have traditionally appeared white with snow; this year the white was the work of blackthorn blossoms – a harbinger of spring. Although a welcome sign after a wet and gloomy winter, the early flowering brings unease for experienced season watchers. Has this plant always flowered in mid-February, I wondered, or is something changing?
Fortunately, the science of recording and understanding seasonal events, phenology, has a long history in Britain. Robert Marsham, an 18th-century naturalist, kept records of the appearance of the flowers, birds and insects in his Norfolk village as far back as 1736. Marsham’s descendants continued the recording until 1958. The Woodland Trust maintains the tradition with Nature’s Calendar, a scheme in which members of the public are invited to record various seasonal events.
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- Scris de: Paul Ashton
Bifidobacterium breve, or B breve for short, is a bacterial species that’s found in the human intestine. It’s especially relevant in early life, being one of the most abundant bacteria in the newborn gut.
B breve is a species of the genus Bifidobacterium and is considered key in the development of a healthy gut. It has been studied extensively over the years to uncover how it benefits us from our first days of life.
Some of the benefits associated with this species include protection against pathogens, modulation of the immune system, and provision of nutrients through the breakdown of non-digestible carbohydrates from the diet.
We’re still learning about the origin of B breve. But vertical transmission, where the origin is the mother and the transfer to the baby occurs either during or after birth, is understood to be the main source of microbes at an early age.
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- Scris de: Rocío Sánchez Gallardo
Some researchers are targeting artificial foods as a leading public health problem. As with so many dietary issues, though, the evidence tells a more nuanced tale.
After decades of searching, many scientists believe they have finally pinned down the main problem with our modern diets—the factor driving ever-escalating rates of obesity, diabetes, heart disease and any number of other serious chronic conditions. The culprit isn’t saturated fats, trans fats or some new killer fat you haven’t of. It’s not cholesterol, carbs or sugars; dairy, gluten or meat. It isn’t a specific thing at all.
The problem, according to this increasingly popular argument, is that we’re eating lots of ultra-processed food or UPF. Traditionally, people used limited processing techniques such as cooking and pickling to preserve food or to make it more pleasant to eat. Modern food companies transform food much more extensively through techniques such as extrusion and molding, adding lab-derived components including flavorings, emulsifiers and preservatives. They use this additional processing to make foods that are cheaper, longer-lasting and more convenient.
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- Scris de: Amos Zeeberg
In a now-classic series of experiments, researchers teased out the deep-rooted nature of human bias simply by distributing red shirts and blue shirts to groups of 3- to 5-year-olds at a day care center. In one classroom, teachers were asked to divide children into groups based on the color of their shirts. In another, teachers were instructed to overlook the shirt colors. After three weeks, children in both classrooms tended to prefer being with classmates who wore the same color as themselves—no matter what the teachers did.
This preference for people who seem to belong to our own tribe forms early and drives our choices throughout life. There appears to be no avoiding it: We are all biased. Even as we learn to sort shapes and colors and distinguish puppies from kittens, we also learn to categorize people on the basis of traits they seem to share. We might associate women who resemble our nannies, mothers, or grandmothers with nurturing or doing domestic labor. Or following centuries of racism, segregation, and entrenched cultural stereotypes, we might perceive dark-skinned men as more dangerous than others.
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- Scris de: Jyoti Madhusoodanan
“Cast a vote for a greener planet, lower food bills, better health and kindness to animals. And you don’t even have to wait for a general election,” states the global Veganuary campaign that encourages people to eat plant-based throughout January.
Transforming the world’s food system through large-scale reduction in meat production is essential if we are to preserve the planet’s natural ecosystems. But I don’t believe Veganuary’s solution is the way to do that.
While the switch to eating vegan food may seem empowering, it places an unrealistic pressure upon consumers to drive the shift to plant-based foods. By failing to highlight the state-backed corporate power at the heart of the food system, Veganuary arguably disempowers its followers.
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- Scris de: Benjamin Selwyn
According to Greek mythology, Zeus punished Prometheus for giving fire to humans. He chained Prometheus up and set an eagle to feast on his liver. Each night, the liver grew back and each day, the eagle returned for his feast. In reality, can a liver really grow back?
The liver is the largest internal organ in the human body. It is needed for hundreds of bodily processes, including breaking down toxins such as alcohol. As it is the first organ to “see” alcohol that has been drunk, it is not surprising that it is the most susceptible to alcohol’s effects. However, other organs, including the brain and heart, can also be damaged by long-term heavy alcohol use.
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- Scris de: Ashwin Dhanda
Wegovy, Ozempic and Mounjaro are weight loss and diabetes drugs that have made quite a splash in health news. They target regulatory pathways involved in both obesity and diabetes and are widely considered breakthroughs for weight loss and blood sugar control.
But do these drugs point toward a root cause of metabolic disease? What inspired their development in the first place?
It turns out your body produces natural versions of these drugs – also known as incretin hormones – in your gut. It may not be surprising that nutrients in food help regulate these hormones. But it may intrigue you to know that the trillions of microbes in your gut are key for orchestrating this process.
I am a gastroenterologist at the University of Washington who studies how food and your gut microbiome affect health and disease. Here’s an inside-out perspective on the role natural gut hormones and healthy food play in metabolism and weight loss.
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- Scris de: Christopher Damman
Researchers have identified an entirely new class of antibiotic that can kill bacteria that are resistant to most current drugs.
Zosurabalpin is highly effective against the bacterium carbapenem-resistant Acinetobacter baumannii (Crab), which is classified as a “priority 1” pathogen by the World Health Organization due to its growing presence in hospitals.
Crab can kill up to 60% of people infected with it. It commonly causes infections of the urinary tract, respiratory tract and blood stream, potentially leading to sepsis. It is responsible for around 20% of infections in places like hospitals, care homes or other similar healthcare settings.
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- Scris de: Jonathan Cox
It’s official: 2023 was Earth’s hottest year ever recorded, beating the previous record set in 2016 by a huge margin. Last year was also the first in which the world was close to 1.5°C (1.48°C) hotter than the pre-industrial average (1850-1900). We are brushing against the threshold scientists urged us to limit long-term warming to.
Some scientists, including former Nasa climatologist James Hansen, predict 2024 will be humanity’s first year beyond 1.5°C. As what were once dire warnings from climate experts become our shared reality, what can you expect?
The 1.5°C temperature target, enshrined in the 2015 Paris agreement, is not shattered on first contact. Most of the climate tipping points scientists fear could send warming hurtling out of control are not expected until Earth is consistently warmer than 1.5°C. The global average temperature is likely to dip down again once the present El Niño (a warm phase in a natural cycle focused on the equatorial Pacific Ocean) dissipates.
Instead, 2024 could be our first glimpse of Earth at 1.5°C. Here’s what research suggests it will look like for people and nature.
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- Scris de: Jack Marley
Brad E Tucker, Australian National University
What is the universe made of? This question has driven astronomers for hundreds of years.
For the past quarter of a century, scientists have believed “normal” stuff like atoms and molecules that make up you, me, Earth, and nearly everything we can see only accounts for 5% of the universe. Another 25% is “dark matter”, an unknown substance we can’t see but which we can detect through how it affects normal matter via gravity.
The remaining 70% of the cosmos is made of “dark energy”. Discovered in 1998, this is an unknown form of energy believed to be making the universe expand at an ever-increasing rate.
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- Scris de: Brad E Tucker
As 2023 rolls to a close, Knowable Magazine has looked back over its articles and canvassed editorial committee members from the 51 academic journals — covering analytical chemistry to vision science — published by Knowable’s parent company, Annual Reviews. From good news to bad, from novel vaccines to insect invaders, this year left us with much to ponder. Here we present 12 newsworthy developments from 2023.
Jabs for hope
Hot on the heels of the Covid-19 vaccine success story (including updated jabs that target Omicron subvariants of the rapidly shifting virus), 2023 saw the greenlighting of several new vital vaccines. Abrysvo and Arexvy, the first vaccines against respiratory syncytial virus (RSV), a cold-like virus that can be dangerous for the old or the young, are now available in the United States and elsewhere. And the World Health Organization has recommended a second malaria vaccine, R21, following RTS,S in 2021. RTS,S has already been given to nearly 2 million children in Africa; the new vaccine is about half the price.
This double hit against malaria is a “huge win” for kids, says Matthew Laurens, a pediatric infectious disease specialist at the University of Maryland School of Medicine in Baltimore, who wrote about malaria vaccines in a 2022 opinion article for Knowable. “Like Covid-19, we need multiple malaria vaccines if we’re to succeed in combating this deadly disease.”
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- Scris de: Nicola Jones