High blood pressure develops when the force of blood pushing through the arteries stays consistently elevated. Over time, this can damage blood vessels and significantly raise the risk of heart attacks, strokes, and other serious conditions.

Between 2017 and 2020, about 122.4 million (46.7%) adults in the United States were living with high blood pressure, contributing to more than 130,000 deaths. Diet plays a major role. Consuming too much sodium and not enough potassium are key contributors to elevated blood pressure.

Salt Substitutes: A Low-Cost but Underused Option

“Overall, less than 6% of all U.S. adults use salt substitutes, even though they are inexpensive and can be an effective strategy to help people control blood pressure, especially people with difficult-to-treat high blood pressure,” said lead study author Yinying Wei, M.C.N., R.D.N., L.D., and Ph.D. candidate in the departments of applied clinical research and hypertension section, cardiology division, at UT Southwestern Medical Center in Dallas.

“Health care professionals can raise awareness about the safe use of salt substitutes by having conversations with their patients who have persistent or hard-to-manage high blood pressure.”

Salt substitutes work by replacing some or all of the sodium in regular salt with potassium. While potassium salt has a similar flavor, it can develop a slightly bitter taste when heated.

Although many foods naturally contain sodium, most people consume the majority of it through processed foods, packaged items, and restaurant meals. The American Heart Association recommends limiting sodium intake to no more than 2,300 mg per day, with an ideal target of less than 1,500 mg for most adults, especially those with high blood pressure. Even reducing intake by 1,000 mg per day can lead to meaningful improvements in blood pressure and overall heart health.

Two Decades of Data Reveal a Persistent Gap

This study is the first to track long-term trends in salt substitute use across a nationally representative group of U.S. adults. Researchers analyzed data from the National Health and Nutrition Examination Survey (NHANES) collected between 2003 and 2020, focusing on products that replace traditional salt with potassium-enriched or alternative salts.

Who Can Safely Use Salt Substitutes?

The research paid special attention to people with high blood pressure and also examined a subgroup of adults considered safe candidates for salt substitutes. This included individuals with normal kidney function and those not taking medications or supplements that influence potassium levels.

Some salt substitutes contain potassium, which can build up to dangerous levels in people with kidney disease or those taking certain medications or supplements. High potassium levels can lead to abnormal heart rhythms. Because of this, people with high blood pressure should consult a health care professional before making the switch.

Key Findings: Usage Remains Surprisingly Low

The analysis showed that salt substitute use has remained consistently low across the U.S. population:

• Use peaked at 5.4% in 2013-2014 but dropped to 2.5% by 2017-March 2020. Data collection for 2020 ended early due to the pandemic.
• Among people eligible to safely use salt substitutes, only 2.3% to 5.1% reported using them.
• Usage was highest among individuals with high blood pressure controlled by medication (3.6%-10.5%), followed by those whose blood pressure remained uncontrolled despite treatment (3.7%-7.4%).
• Fewer than 5.6% of people with untreated high blood pressure or normal blood pressure used salt substitutes.
• People who ate at restaurants three or more times per week appeared less likely to use salt substitutes, although this difference was not statistically significant after adjusting for demographic factors.

“Salt substitute use remained uncommon over the last two decades including among people with high blood pressure,” Wei said. “Even among individuals with treated and poorly managed or untreated high blood pressure, most continued to use regular salt.”

Experts Call It a Missed Opportunity

“This study highlights an important and easy missed opportunity to improve blood pressure in the U.S. — the use of salt substitutes,” said Amit Khera, M.D., M.Sc., FAHA, an American Heart Association volunteer expert.

“The fact that use of salt substitutes remains so low and has not improved in two decades is eye-opening and reminds patients and health care professionals to discuss the use of these substitutes, particularly in visits focused on high blood pressure.”

Khera, who was not involved in the research, is a professor of medicine, clinical chief of cardiology, and director of preventive cardiology at UT Southwestern Medical Center in Dallas.

Study Limitations and Future Questions

The researchers note several limitations. Salt substitute use was self-reported, which may have led to underreporting or misclassification. The study also grouped all types of salt substitutes together, so it could not distinguish potassium-based products from other alternatives. In addition, the data did not track how much salt substitute participants used.

“Future research should explore why salt substitute-use remains low by investigating potential barriers, such as taste acceptance, cost and limited awareness among both patients and clinicians,” said Wei. “These insights may help guide more targeted interventions.”

Study Design and Participant Details

The analysis included 37,080 adults ages 18 and older (37.9% were aged 18-39, 36.9% were aged 40-59 years, and 25.2% were aged 60 and older). 50.6% of participants were women, 10.7% self-identified as non-Hispanic Black, and 89.3% reported other racial and ethnic backgrounds.

Participants were grouped based on whether they had high blood pressure (≥130/80 mm Hg) and whether they were using medication: controlled hypertension, uncontrolled hypertension, untreated hypertension, or normal blood pressure.

Salt use was categorized as ordinary salt (iodized salt, sea salt, kosher salt), salt substitute (potassium-enriched or other salt substitute), or no salt use.

A subgroup analysis focused on people eligible for salt substitutes, defined as those with healthy kidney function (estimated glomerular filtration rate ≥ 60) and no use of medications or supplements that affect potassium levels. Researchers also examined how often participants ate at restaurants. All results accounted for NHANES sampling methods and survey design.

Research Highlights

• Salt substitutes remain rarely used despite their ability to lower sodium intake and help manage blood pressure.
• Increasing awareness could help improve outcomes, especially for people with difficult-to-treat hypertension.
• The study was funded by the National Institutes of Health.

Note: The study featured in this article is a research abstract. Abstracts presented at American Heart Association’s scientific meetings are not peer-reviewed, and the findings are considered preliminary until published as a full manuscript in a peer-reviewed scientific journal.

At the center of all this is growth hormone, which surges during sleep. But scientists have long puzzled over why poor sleep, especially the early deep stage known as non-REM sleep, leads to lower levels of this critical hormone.

Scientists Discover the Brain Circuit Behind It

Researchers at the University of California, Berkeley, have now uncovered the answer. In a study published in Cell, they mapped the brain circuits that control growth hormone release during sleep and identified a new feedback system that keeps those levels in balance.

This discovery offers a clearer understanding of how sleep and hormones work together. It may also open the door to new treatments for sleep disorders linked to metabolic diseases like diabetes, as well as neurological conditions such as Parkinson’s and Alzheimer’s.

“People know that growth hormone release is tightly related to sleep, but only through drawing blood and checking growth hormone levels during sleep,” said study first author Xinlu Ding, a postdoctoral fellow in UC Berkeley’s Department of Neuroscience and the Helen Wills Neuroscience Institute. “We’re actually directly recording neural activity in mice to see what’s going on. We are providing a basic circuit to work on in the future to develop different treatments.”

Lack of sleep does more than leave you tired. Because growth hormone helps control how the body processes sugar and fat, poor sleep can increase the risk of obesity, diabetes, and heart disease.

The Brain Regions Driving Growth Hormone

The system behind this process is buried deep in the hypothalamus, an ancient part of the brain shared by all mammals. Here, specialized neurons release signals that either trigger or suppress growth hormone.

Two key players are growth hormone releasing hormone (GHRH), which stimulates release, and somatostatin, which inhibits it. Together, they coordinate hormone activity across the sleep-wake cycle.

Once growth hormone enters the system, it activates the locus coeruleus, a brainstem region that controls alertness, attention, and cognitive function. Disruptions in this area are linked to a wide range of neurological and psychiatric disorders.

“Understanding the neural circuit for growth hormone release could eventually point toward new hormonal therapies to improve sleep quality or restore normal growth hormone balance,” said Daniel Silverman, a UC Berkeley postdoctoral fellow and study co-author. “There are some experimental gene therapies where you target a specific cell type. This circuit could be a novel handle to try to dial back the excitability of the locus coeruleus, which hasn’t been talked about before.”

How Sleep Stages Control Hormone Release

To study this system, researchers recorded brain activity in mice by inserting electrodes and stimulating neurons with light. Because mice sleep in short bursts throughout the day and night, they provided a detailed view of how growth hormone changes across sleep stages.

The team found that GHRH and somatostatin behave differently depending on whether the brain is in REM or non-REM sleep.

During REM sleep, both hormones increase, leading to a surge in growth hormone. During non-REM sleep, somatostatin drops while GHRH rises more modestly, still boosting hormone levels but in a different pattern.

A Surprising Feedback Loop in the Brain

The researchers also uncovered a feedback loop that links growth hormone to wakefulness. As sleep continues, growth hormone gradually builds up and stimulates the locus coeruleus, nudging the brain toward waking.

But there is a twist. When this brain region becomes too active, it can actually trigger sleepiness instead, creating a delicate balance between sleep and alertness.

“This suggests that sleep and growth hormone form a tightly balanced system: Too little sleep reduces growth hormone release, and too much growth hormone can in turn push the brain toward wakefulness,” Silverman said. “Sleep drives growth hormone release, and growth hormone feeds back to regulate wakefulness, and this balance is essential for growth, repair and metabolic health.”

Why It Matters for Brain and Body

This balance does more than affect physical growth. Because growth hormone works through brain systems that control alertness, it may also influence how clearly you think and how focused you feel.

“Growth hormone not only helps you build your muscle and bones and reduce your fat tissue, but may also have cognitive benefits, promoting your overall arousal level when you wake up,” Ding said.

Funding and Research Team

The research was supported by the Howard Hughes Medical Institute (HHMI) and the Pivotal Life Sciences Chancellor’s Chair fund. Yang Dan holds the Pivotal Life Sciences Chancellor’s Chair in Neuroscience. The study also included collaborators from UC Berkeley and Stanford University.

Knee osteoarthritis (KOA) is a widespread and often disabling condition that affects millions of older adults. It leads to ongoing pain and stiffness in the knee joint, making everyday movement more difficult. Many patients rely on anti-inflammatory medications, but these drugs can carry risks, including gastrointestinal and cardiovascular side effects.

Large Study Compares 12 Non-Drug Therapies

To better understand which non-drug treatments work best, researchers analyzed data from 139 clinical trials involving nearly 10,000 participants. The study compared 12 different therapies, including laser therapy, electrical stimulation, knee braces, insoles, kinesiology tape, water-based therapy, exercise, and ultrasound.

By combining results across all of these studies using a network meta-analysis, the researchers were able to rank each treatment based on its effectiveness.

Knee Braces, Hydrotherapy, and Exercise Lead

Knee braces ranked highest overall, showing strong results in reducing pain, improving joint function, and easing stiffness. Hydrotherapy — exercises or treatments performed in warm water — was especially helpful for pain relief. Regular exercise also delivered consistent benefits, improving both pain levels and physical function.

Some advanced treatments, such as high-intensity laser therapy and shock wave therapy, provided moderate improvements. In contrast, ultrasound consistently ranked as the least effective option.

Study Limitations and Future Research

The researchers note that variations in study design, smaller sample sizes in some trials, and differences in how long treatments were used could affect how precise the rankings are. Even so, the overall findings suggest that physical therapy approaches offer meaningful benefits without the risks linked to anti-inflammatory medications.

Future research should explore how combining different therapies might improve outcomes further and whether these approaches are cost-effective in real-world care.

Safer Alternatives to Pain Medications

The authors add: “Knee braces, hydrotherapy, and exercise are the most effective non-drug therapies for knee osteoarthritis. They reduce pain and improve mobility without the gastrointestinal or cardiovascular risks linked to common pain medications. Patients and clinicians should prioritize these evidence-based options.”

“Our analysis of nearly 10,000 patients reveals that simple, accessible therapies like knee bracing and water-based exercise outperform high-tech options like ultrasound. This could reshape clinical guidelines to focus on safer, lower-cost interventions.”

NASA announced that researchers using the James Webb Space Telescope examined GRB 250702B, a long gamma-ray burst and one of the most energetic types of events in the universe. These bursts typically occur when a massive star collapses into a black hole, producing a brief and intense flash of high-energy gamma rays. This event behaved very differently.

“This object shows extreme properties that are difficult to explain,” said Huei Sears, a postdoctoral researcher in the Department of Physics and Astronomy at the Rutgers School of Arts and Sciences who is studying the explosion. “Usually, these bursts are over in less than a minute, but GRB 250702B lasted for hours and even showed signs of X-ray activity a day prior.”

Global Observations Reveal Unusual Behavior

Sears explained that observatories around the world are analyzing data from the event. This includes teams working with China’s Einstein Probe and the National Science Foundation’s Very Large Array, which is widely recognized from its appearance in the science fiction film Contact.

The gamma-ray emission continued for at least seven hours, nearly doubling the duration of the previous record holder. NASA also released an animation showing one possible scenario for the event. In this model, a black hole about three times the mass of the Sun, with an event horizon just 11 miles (18 kilometers) wide, orbits and merges with a companion star.

“This is certainly an outburst unlike any other we have seen in the past 50 years,” said Eliza Neights, an astronomer at NASA’s Goddard Space Flight Center in Maryland.

Possible Explanations Involving Black Holes

Scientists are considering several explanations. One possibility is that this was an unusually extreme gamma-ray burst. Another is that it was a tidal disruption event, in which a black hole thousands of times more massive than the Sun tears apart a star that ventured too close. A more unusual idea suggests a smaller black hole merged with a stripped helium star and consumed it from within.

Regardless of the exact cause, the black hole did far more than take a small bite. It unleashed powerful jets of energy that shot across space.

Multi-Telescope Effort Captures the Event

NASA’s Fermi Gamma-ray Space Telescope first detected the burst on July 2, prompting rapid follow-up observations from other instruments. The event was so intense that no single telescope could capture the full picture. Scientists combined data from space-based and ground-based observatories, collecting gamma rays, X-rays, infrared light, and radio signals. The explosion was not visible in ordinary light.

“Only through the combined power of instruments on multiple spacecraft could we understand this event,” said Eric Burns, an astrophysicist at Louisiana State University.

Distant Galaxy Adds to the Mystery

Images from the Hubble Space Telescope revealed an unusual galaxy at the location of the burst. Initially, it appeared as though two galaxies might be merging, or that a single galaxy was split by a dark band of dust. Later, Webb observations showed the galaxy lies about 8 billion light-years away, meaning the explosion occurred long before Earth formed.

To better understand the host galaxy, Sears led follow-up observations using Webb’s NIRCam, its main near-infrared imaging instrument, several months after the event.

“In such vibrant and unprecedented detail, we see just one very large galaxy with a dust lane,” Sears said. “The galaxy has such complex structure that it’s not 100% clear if there’s anything left to see of the explosion, but if there is, it’s really faint.”

Mystery Remains Unsolved

This finding supports the idea that GRB 250702B was a gamma-ray burst rather than a tidal disruption event. Even so, researchers have not reached a definitive conclusion.

“We have only seen a few tidal disruption events of this type, so we don’t know for sure how they’re supposed to evolve,” Sears said. “A lot of the studies on this explosion provide different, and sometimes contradictory, explanations. It’s still early in our understanding of what really happened.”

Whatever the final explanation, scientists agree the event is both rare and significant.

“This gives us a unique chance to study the extremes of how stars and black holes evolve,” Sears said. “GRB 250702B could even be the discovery of something unexpected and new.”

The Webb telescope also is supported by the European Space Agency (ESA), and the Canadian Space Agency (CSA).