Study finds key to why obese people lose pleasure in eating rich foods
ST. PAUL, Minn., March 26 (UPI) -- While it seems like a contradiction, many obese people do not enjoy eating rich, calorie-laden foods.
A study published Wednesday indicates that low levels of a key brain chemical among overweight patients with high-fat diets is responsible for a loss of pleasure from food.
Researchers from the University of California-Berkeley say they may have found why people with obesity have been shown to take less pleasure in eating fatty foods than those of normal weight. The culprit, they say, is a deficit of the neuropeptide neurotensin which is linked to the pleasure activator dopamine.
Neuropeptides act as a signaling molecule in the nervous system, and can affect appetite. These molecules are made up of short chains of amino acids, like other peptides, and they play a crucial role in communication between neurons and other cells.
The findings are significant because diminishing pleasure response from eating high-fat foods can lead obese patients to continue or even increase their unhealthy eating patterns "out of habit or boredom, rather than genuine enjoyment," according to the study, which was published in the journal Nature.
As counterintuitive as it may initially sound, the authors say that restoring the pleasure in eating high-fat foods via the replenishment of neurotensin actually could help reduce the progression of obesity and provide a valuable new tool in fight against the global obesity epidemic.
The need for new strategies is a stark one. More than half of adults and one-third of children and teens worldwide will be overweight or obese by 2050, according to a comprehensive study released earlier this year.
Overweight and obesity rates in adults, children and teens more than doubled over the past three decades, afflicting 2.1 billion adults and 493 million young people with excess weight.
A link between neurotensin, or NT, and eating disorders has been established in previous studies, which found that changes in NT levels are associated with obesity or eating disorders, leading doctors to believe that disrupted NT signaling may contribute to body weight disturbance.
Specifically, research has centered around the NT receptors located in a specific brain region that connect to the dopamine "reward" and "pleasure" network.
However, a key question remained: Does a high-fat diet somehow influence the release of NT in the brain? The new study, led by Stephan Lammel, an associate professor of neurobiology at UC Berkeley's Department of Neuroscience, presents evidence that the answer to this question is yes, leading to hopes that by "upregulating" NT -- perhaps through dietary changes or genetic manipulation -- the pleasure of eating can be restored.
Lammel said the study, which was supported the National Institutes of Health, the McKnight Foundation, the One Mind Foundation and others, has "uncovered a concrete mechanism that may link chronic high-fat diet exposure to a loss of pleasure in eating -- a phenomenon that's been observed for years but lacked a clear explanation."
Specifically, the researchers found that NT becomes significantly reduced in a key brain circuit in obese mice. This reduction essentially blunts the motivational value of enjoyable foods like sugar and fat.
"What's especially compelling is that restoring neurotensin levels -- either by switching back to a regular diet or through targeted genetic approaches -- can bring back that sense of reward," Lammel told UPI in a statement. "This not only increased feeding motivation in specific contexts, but also normalized weight gain, improved mobility and reduced anxiety."
Clinically, "that's really important," he added, saying it suggests that part of the challenge in obesity may not just be overeating due to pleasure, but also continuing to eat without pleasure -- out of habit or diminished reward.
"If we can find ways to restore or rebalance neurotensin signaling in the brain selectively, we may be able to help people regain healthier eating behaviors without broadly suppressing appetite or affecting other systems," he said.
The idea that making eating more pleasurable for obese patients as a way to help them manage their weight may seem paradoxical at first, Lammel admitted.
"After all, we often assume that the more we enjoy food, the more likely we are to overeat," he said. "But our study shows that the reality is more nuanced. What we found is that in mice exposed to a chronic high-fat diet, the brain's reward response -- particularly in circuits involving dopamine and neurotensin -- becomes blunted," but even so, they kept on eating the unhealthy food.
This uncoupling of reward from consumption is important "because it suggests that overeating in obesity isn't always driven by pleasure -- it can become automatic or habitual, which makes it harder to regulate."
So, the paradox is that bringing back the "right" kind of pleasure -- this is, pleasure that's appropriately tied to the reward value of food -- may actually help break the cycle of mindless or habitual overeating, the study team found.
"It's not about encouraging indulgence, but about restoring balance," Lammel said. "If food becomes pleasurable again in a meaningful and regulated way, the body may naturally recalibrate toward healthier patterns of intake."
Another prominent researcher of the connection between NT, dopamine and obesity said the UC Berkeley study represents a significant advancement in the understanding of the role brain chemistry plays in determining our eating habits.
Gina Leinninger, a professor of physiology and leader of the Leinninger Laboratory at Michigan State University's Neuroscience Program, is an expert on how neurons in the brain's hypothalamus regulate energy balance, and how disruption of these neurons contributes to the development of obesity and metabolic disease.
Leinninger, who was not connected to the study, told UPI the work sheds a new light on what had been known previously.
"Neurotensin has long been connected to modulating feeding, but how and where has remained a mystery," she said. "This work makes important strides in connecting neurotensin to the dopamine system that shape show much we want to eat, and therefore how much we do it."

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Yahoo
3 hours ago
- Yahoo
Insmed Announces Positive Topline Results from Phase 2b Study of Treprostinil Palmitil Inhalation Powder (TPIP) as Once-Daily Therapy in Patients with Pulmonary Arterial Hypertension
–The Study Met Primary and All Secondary Efficacy Endpoints– Statistically Significant 35% Placebo-Adjusted Reduction from Baseline in Pulmonary Vascular Resistance for the Primary Endpoint (p<0.001) 35.5 Meter Placebo-Adjusted Improvement in Six-Minute Walk Distance for the Secondary Efficacy Endpoint (p=0.003) 60% Placebo-Adjusted Reduction from Baseline in NT-proBNP Concentrations for the Secondary Efficacy Endpoint (p<0.001) Results Were Assessed Approximately 24 Hours After Administration, Demonstrating Sustained Benefit Throughout the 24-Hour Dosing Period –TPIP Was Well Tolerated in the Study, with 75% of Patients Titrating to the Highest Dose– –Insmed to Immediately Engage with FDA to Inform Phase 3 Trial Design with Studies Expected to Begin Before End of 2025 for PH-ILD and in Early 2026 for PAH– –Insmed to Host Investor Call at 8:00 AM ET on Tuesday, June 10, 2025– BRIDGEWATER, N.J., June 10, 2025 /PRNewswire/ -- Insmed Incorporated (Nasdaq: INSM), a people-first global biopharmaceutical company striving to deliver first- and best-in-class therapies to transform the lives of patients facing serious diseases, today announced positive topline results from its randomized, double-blind, placebo-controlled Phase 2b study evaluating the efficacy and safety of treprostinil palmitil inhalation powder (TPIP), administered once daily in patients with pulmonary arterial hypertension (PAH, World Health Organization Group 1). The study met its primary endpoint and all secondary efficacy endpoints. For the primary endpoint, the placebo-adjusted reduction from baseline in pulmonary vascular resistance (PVR) was 35% with Least Squares (LS) mean ratio of 0.65 (95% CI: 0.54, 0.79; p<0.001). For the secondary efficacy endpoints, the placebo-adjusted improvement in six-minute walk distance (6MWD) was 35.5 meters (95% CI: 11.2, 60.7; p=0.003) and the placebo-adjusted reduction from baseline in N-terminal pro b-type natriuretic peptide (NT-proBNP) concentrations, a biomarker for cardiac stress, was 60% with LS mean ratio of 0.40 (95% CI: 0.27, 0.59; p<0.001). These results demonstrate the durability of TPIP's therapeutic effect as a once-daily therapy based on efficacy being evaluated approximately 24 hours after therapy was administered. Based on these results, Insmed will immediately engage with the U.S. Food and Drug Administration (FDA) regarding the Phase 3 trial design for PAH. Insmed plans to initiate a Phase 3 trial in patients with pulmonary hypertension associated with interstitial lung disease (PH-ILD) before the end of 2025 and a Phase 3 trial in patients with PAH in early 2026. "The statistically significant and clinically meaningful results shown with TPIP in pulmonary arterial hypertension mark a potential breakthrough for patients and the future of prostanoid therapy," said Gene Sullivan, M.D., Chief Product Strategy Officer of Insmed. "TPIP was designed with the goal of fully harnessing the potential of treprostinil and providing meaningful benefit to patients. These unprecedented Phase 2b results unequivocally demonstrate TPIP's potential to be a highly effective and well-tolerated once-daily prostanoid therapy for the treatment of PAH across disease severities and background treatment regimens. We look forward to expanding upon these results in the upcoming Phase 3 program." The study was conducted at 44 sites globally, and a total of 102 patients were randomized 2:1 to receive either TPIP (n=69) or placebo (n=33) for 16 weeks. Demographics and baseline characteristics were similar in both study arms. Patients started at a dose of 80 µg once daily (TPIP or matching placebo) and were titrated up to their maximum tolerated dose, or to the maximum allowable dose of 640 µg, once daily over a three-week period, with the possibility of a final dose increase occurring at Week 5. Of the patients treated with TPIP, 84% titrated to at least 480 µg once daily (n=58) and 75% titrated to the maximum allowed dose of 640 µg once daily (n=52). Overall, 90% of patients receiving TPIP (n=62) and all patients receiving placebo completed the study. Once-daily TPIP therapy was well tolerated in the study. Treatment-emergent adverse events (TEAEs) occurred in 88.4% of patients who received TPIP versus 75.8% of patients who received placebo; serious TEAEs were observed in 7.2% of patients who received TPIP versus 3.0% of patients who received placebo; and severe TEAEs were observed in 5.8% of patients who received TPIP versus 3.0% of patients who received placebo. TEAEs leading to treatment discontinuation were experienced by 5.8% of patients taking TPIP; there were none in the placebo arm. There were no deaths in the study. The most common TEAEs occurring in at least 5.0% of patients in any study arm, and more frequently with TPIP than with placebo, were cough (40.6%, 21.2%), headache (31.9%, 15.2%), fatigue (10.1%, 3.0%), chest discomfort (8.7%, 0.0%), flushing (8.7%, 3.0%), upper respiratory tract infection (7.2%, 3.0%), and non-cardiac chest pain (5.8%, 3.0%) for TPIP and placebo, respectively. "Today's outstanding results for TPIP represent more than a decade of hard work and the application of innovative chemistry intended to deliver a safe and effective, once-daily inhaled prostanoid therapy for patients with PAH, a devastating, progressive disease," said Martina Flammer, M.D., MBA, Chief Medical Officer of Insmed. "Having met the primary endpoint with high statistical significance, as well as seeing positive results for all secondary efficacy endpoints, we are excited about TPIP's potential to become the prostanoid of choice. Thank you to the many patients and clinicians who participated in this study and contributed to today's historic outcome." All patients who completed the Phase 2b study were eligible to enroll in the long-term open-label extension, which will evaluate TPIP up to a maximum allowable dose of 1,280 µg once daily. Of the patients who completed the Phase 2b study (n=95), 95% enrolled in the open-label extension. Insmed plans to present detailed results from the Phase 2b study of TPIP in PAH and the open-label extension at future medical meetings. Topline results from the Phase 2a study of TPIP in patients with PH-ILD were previously reported in May 2024. Results of the Phase 2b study of TPIP in PAH, including exploratory analyses, will be discussed during the Company's investor conference call on Tuesday, June 10, 2025, at 8:00 AM ET and as part of an investor presentation available at Conference Call Information Insmed will host a conference call today at 8:00 AM ET to discuss the TPIP Phase 2b study results in PAH. The call can be accessed by dialing (888) 210-2654 (U.S. and Canada) or (646) 960-0278 (international) and entering the conference ID number 7862189. The call will also be webcast live on the Company's website at A replay of the conference call will be accessible approximately two hours after its completion through Tuesday, June 17, 2025, by dialing (800) 770-2030 (U.S. and Canada) or (609) 800-9909 (international) and referencing conference ID number 7862189. A webcast of the call will also be archived for 90 days under the Investor Relations section of the Company's website at About TPIP Treprostinil palmitil inhalation powder (TPIP) is a dry powder formulation of treprostinil palmitil, a treprostinil prodrug consisting of treprostinil linked by an ester bond to a 16-carbon chain. Developed entirely in Insmed's laboratories, TPIP is a potentially highly differentiated prostanoid being evaluated as a once-daily therapy for the treatment of patients with PAH, PH-ILD, and other rare and serious pulmonary disorders. TPIP is administered in a capsule-based inhalation device. TPIP is an investigational drug product that has not been approved for any indication in any jurisdiction. About the Phase 2b Study The Phase 2b study of treprostinil palmitil inhalation powder (TPIP) in patients with pulmonary arterial hypertension (PAH) was a randomized, double-blind, multicenter, placebo-controlled study designed to evaluate the efficacy, safety, and pharmacokinetics of TPIP, administered once daily, in patients diagnosed with PAH (World Health Organization Group 1). The study was conducted at 44 sites and enrolled 102 adult participants. Patients started at a dose of 80 µg once daily (TPIP or matching placebo) and were titrated up to their maximum tolerated dose, or to the maximum allowable dose of 640 µg, once daily over a three-week period, with the possibility of a final dose increase occurring at Week 5. Patients self-administered TPIP or placebo using a capsule-based inhalation device. The primary endpoint was change from baseline in pulmonary vascular resistance (PVR) versus placebo at Week 16. Secondary endpoints were six-minute walk distance (6MWD), N-terminal pro b-type natriuretic peptide (NT-proBNP) concentrations, pharmacokinetics, and safety/tolerability. Patients who completed the study could enroll in a long-term open-label extension, with the option to titrate up to a maximum tolerated dose of 1,280 µg once daily. About Pulmonary Arterial Hypertension Pulmonary arterial hypertension (PAH) is a serious, progressive, rare disease in which the blood vessels in the lungs narrow or become obstructed, leading to high blood pressure in the pulmonary arteries. The most common symptoms include shortness of breath, chest pain, dizziness or fainting, fatigue, and weakness. It is estimated that approximately 35,000 patients in the U.S., 40,000 patients in the EU5 (France, Germany, Italy, Spain, and the UK), and 15,000 patients in Japan have been diagnosed with the disease. Untreated, PAH can be debilitating and often fatal. About Insmed Insmed Incorporated is a people-first global biopharmaceutical company striving to deliver first- and best-in-class therapies to transform the lives of patients facing serious diseases. The Company is advancing a diverse portfolio of approved and mid- to late-stage investigational medicines as well as cutting-edge drug discovery focused on serving patient communities where the need is greatest. Insmed's most advanced programs are in pulmonary and inflammatory conditions, including a therapy approved in the United States, Europe, and Japan to treat a chronic, debilitating lung disease. The Company's early-stage programs encompass a wide range of technologies and modalities, including gene therapy, AI-driven protein engineering, protein manufacturing, RNA end-joining, and synthetic rescue. Headquartered in Bridgewater, New Jersey, Insmed has offices and research locations throughout the United States, Europe, and Japan. Insmed is proud to be recognized as one of the best employers in the biopharmaceutical industry, including spending four consecutive years as the No. 1 Science Top Employer. Visit to learn more. Forward-looking Statements This press release contains forward-looking statements that involve substantial risks and uncertainties. "Forward-looking statements," as that term is defined in the Private Securities Litigation Reform Act of 1995, are statements that are not historical facts and involve a number of risks and uncertainties. Words herein such as "may," "will," "should," "could," "would," "expects," "plans," "anticipates," "believes," "estimates," "projects," "predicts," "intends," "potential," "continues," and similar expressions (as well as other words or expressions referencing future events, conditions or circumstances) may identify forward-looking statements. The forward-looking statements in this press release are based upon the Company's current expectations and beliefs, and involve known and unknown risks, uncertainties and other factors, which may cause the Company's actual results, performance and achievements and the timing of certain events to differ materially from the results, performance, achievements or timings discussed, projected, anticipated or indicated in any forward-looking statements. Such risks, uncertainties and other factors include, among others, the following: the risk that the full data set from the TPIP PAH study or data generated in further clinical trials of TPIP will not be consistent with the topline results of the TPIP PAH study; failure to successfully conduct future clinical trials for TPIP, such as the Company's planned Phase 3 program for TPIP, including due to the Company's potential inability to enroll or retain sufficient patients to conduct and complete the trials or generate data necessary for regulatory approval, among other things; development of unexpected safety or efficacy concerns related to TPIP; failure of third parties on which the Company is dependent to manufacture sufficient quantities of TPIP for clinical needs, to conduct the Company's clinical trials, or to comply with the Company's agreements or laws and regulations that impact the Company's business or agreements with the Company; failure to obtain regulatory approval for TPIP; inaccuracies in the Company's estimates of the size of the potential markets for TPIP or in data the Company has used to identify physicians; expected rates of patient uptake, duration of expected treatment, or expected patient adherence or discontinuation rates, if TPIP is approved; inability of the Company or the Company's third-party manufacturers to comply with regulatory requirements related to TPIP; the Company's inability to obtain adequate reimbursement from government or third-party payors for TPIP or acceptable prices for TPIP, if approved; restrictions or other obligations imposed on us by agreements related to TPIP and failure to comply with our obligations under such agreements; risks that the Company's clinical studies will be delayed or that serious side effects will be identified during drug development; the strength and enforceability of the Company's intellectual property rights or the rights of third parties; and the cost and potential reputational damage resulting from litigation to which the Company may become a party, including product liability claims. The Company may not actually achieve the results, plans, intentions or expectations indicated by the Company's forward-looking statements because, by their nature, forward-looking statements involve risks and uncertainties because they relate to events and depend on circumstances that may or may not occur in the future. For additional information about the risks and uncertainties that may affect the Company's business, please see the factors discussed in Item 1A, "Risk Factors," in the Company's Annual Report on Form 10-K for the year ended December 31, 2024 and any subsequent Company filings with the Securities and Exchange Commission (SEC). The Company cautions readers not to place undue reliance on any such forward-looking statements, which speak only as of the date of this press release. The Company disclaims any obligation, except as specifically required by law and the rules of the SEC, to publicly update or revise any such statements to reflect any change in expectations or in events, conditions or circumstances on which any such statements may be based, or that may affect the likelihood that actual results will differ from those set forth in the forward-looking statements. Contact: Investors:Bryan DunnVice President, Investor Relations(646) Media:Claire MulhearnVice President, Corporate Communications(862) 842-6819media@ View original content to download multimedia: SOURCE Insmed Incorporated
Yahoo
4 hours ago
- Yahoo
When will a vital system of currents in the Atlantic Ocean collapse? Depends on whom you ask.
The Atlantic Ocean as seen from Sachuest Beach in Middletown. (Photo by Alexander Castro/Rhode Island Current) This story was originally published by Grist. Sign up for Grist's weekly newsletter here. Just below Greenland is a menacing stretch of water known as the Cold Blob. As the planet heats up, the Cold Blob remains a spooky outlier — positioned right above the area where the Atlantic Ocean's so-called conveyor belt is supposed to switch back and head south. The Atlantic Meridional Overturning Current, or AMOC for short, comprises an enormous system of currents that carries water and nutrients across the world and plays a large part in stabilizing the global climate. For years, scientists have warned that the AMOC was slowing down, possibly nearing collapse. The Cold Blob is the most immediately visible proof of its decline, likely a result of Greenland's melting glaciers, but research on the deep water current's strength over recent years has varied wildly. New studies published in Nature Geoscience last week and in Nature earlier this year offer some slightly encouraging news. AMOC's decline could be 'much more of a slow, gradual change, rather than an immediate change,' said David Bonan, a postdoctoral fellow at the University of Washington who served as the lead author on the Nature Geoscience study. The full collapse of the current might not be reached this century, rather than around the midcentury mark as other research has predicted. The stakes could hardly be higher. Should the current break down, the most frightening predictions describe a world thrown into chaos: Drought could destroy India, South America, and Africa; the Eastern Seaboard of the United States would see dramatic sea level rise; and an arctic chill would spread across Europe. 'You cannot adapt to this,' said Peter Ditlevsen, the co-author of a 2023 study and an ice and climate researcher at the University of Copenhagen, in an interview with Inside Climate News. 'There's some studies of what happens to agriculture in Great Britain, and it becomes like trying to grow potatoes in northern Norway.' A more gradual change would still cause enormous upheaval, but would give the world more time to put mitigation efforts in place. Part of what makes AMOC's behavior so hard to forecast is that consistent monitoring of the current didn't begin until 2004, so the historical data is limited. When researchers run models to examine AMOC's behavior in the past, they sometimes get baffling results. 'The new models aren't working for AMOC,' said David Thornalley, a paleoclimatologist at University College London, who wasn't involved with the latest research. 'Some people would say we don't 100 percent know what AMOC did through the 20th century.' The February study in Nature found that the current is more stable than expected. Winds in the Southern Ocean churn the incoming Arctic water up to the surface and send it northward again. The research showed AMOC slowing between 20 to 80 percent by 2100, but not collapsing entirely. This is obviously a pretty big range, and 'even a moderate weakening could affect rainfall patterns, sea level rise, and the ocean's ability to take up carbon,' said Jonathan Baker, lead author of the study and a senior scientist in the ocean, cryosphere, and climate group at the Met Office, the weather service for the U.K. Between 2009 and 2010, AMOC wobbled — slowing about 30 percent — and sea levels rose 5 inches between New York City and Newfoundland within a year. The most recent study in Nature Geosciences narrowed that range to a weakening of 18 to 43 percent by 2100 after investigating how previous models were making their calculations. Models that predict an imminent collapse tend to assume AMOC is fairly strong at the moment, extending to great depths within the ocean and forcing warm surface water deep into the sea. Models that presented the current as weaker, with a shallower reach into the deep ocean, were less affected by warming surface waters. Bonan and his team found that the North Atlantic is 'a little bit more aligned with these weaker models,' he said. 'If you warmed up the surface [water], or if you have increased sea ice melt or Greenland Ice Sheet melt, a lot of those surface properties are probably just going to stay at the upper ocean, rather than going deeper into the ocean.' Still, Bonan highlighted the need for more advanced models that may be able to better forecast interactions between ice sheets and the ocean. Thornalley underlined those concerns — without sophisticated modeling of meltwater coming off Greenland, he said, these studies might be painting an overly rosy picture. 'If you look at what all the models do after 2100, a lot of them go on to collapse,' he said. One problem with estimating a drop-dead date for AMOC is that researchers still don't understand when the current might reach a tipping point, a threshold that, when crossed, will have a cascading effect from which there is no return. Whether the current dies a slower or faster death won't matter in the long run if the world breaches that threshold. 'It's a good study,' Thornalley said. 'Does it make me calmer about the future? No.' Grist is a nonprofit, independent media organization dedicated to telling stories of climate solutions and a just future. Learn more at SUBSCRIBE: GET THE MORNING HEADLINES DELIVERED TO YOUR INBOX


Medscape
5 hours ago
- Medscape
As Cannabis Users Age, Health Risks Appear To Grow
Benjamin Han, a geriatrician and addiction medicine specialist at the University of California-San Diego, tells his students a cautionary tale about a 76-year-old patient who, like many older people, struggled with insomnia. 'She had problems falling asleep, and she'd wake up in the middle of the night,' he said. 'So her daughter brought her some sleep gummies' — edible cannabis candies. 'She tried a gummy after dinner and waited half an hour,' Han said. Feeling no effects, she took another gummy, then one more — a total of four over several hours. Han advises patients who are trying cannabis to 'start low; go slow,' beginning with products that contain just 1 or 2.5 milligrams of tetrahydrocannabinol, or THC, the psychoactive ingredient that many cannabis products contain. Each of the four gummies this patient took, however, contained 10 milligrams. The woman started experiencing intense anxiety and heart palpitations. A young person might have shrugged off such symptoms, but this patient had high blood pressure and atrial fibrillation, a heart arrhythmia. Frightened, she went to an emergency room. Lab tests and a cardiac work-up determined the woman wasn't having a heart attack, and the staff sent her home. Her only lingering symptom was embarrassment, Han said. But what if she'd grown dizzy or lightheaded and was hurt in a fall? He said he has had patients injured in falls or while driving after using cannabis. What if the cannabis had interacted with the prescription drugs she took? 'As a geriatrician, it gives me pause,' Han said. 'Our brains are more sensitive to psychoactive substances as we age.' Thirty-nine states and the District of Columbia now allow cannabis use for medical reasons, and in 24 of those states, as well as the district, recreational use is also legal. As older adults' use climbs, 'the benefits are still unclear,' Han said. 'But we're seeing more evidence of potential harms.' A wave of recent research points to reasons for concern for older users, with cannabis-related emergency room visits and hospitalizations rising, and a Canadian study finding an association between such acute care and subsequent dementia. Older people are more apt than younger ones to try cannabis for therapeutic reasons: to relieve chronic pain, insomnia, or mental health issues, though evidence of its effectiveness in addressing those conditions remains thin, experts said. In an analysis of national survey data published June 2 in the medical journal JAMA , Han and his colleagues reported that 'current' cannabis use (defined as use within the previous month) had jumped among adults aged 65 or older to 7% of respondents in 2023, from 4.8% in 2021. In 2005, he pointed out, fewer than 1% of older adults reported using cannabis in the previous year. What's driving the increase? Experts cite the steady march of state legalization — use by older people is highest in those states — while surveys show that the perceived risk of cannabis use has declined. One national survey found that a growing proportion of American adults — 44% in 2021 — erroneously thought it safer to smoke cannabis daily than cigarettes. The authors of the study, in JAMA Network Open , noted that 'these views do not reflect the existing science on cannabis and tobacco smoke.' The cannabis industry also markets its products to older adults. The Trulieve chain gives a 10% discount, both in stores and online, to those it calls 'wisdom' customers, 55 or older. Rise Dispensaries ran a yearlong cannabis education and empowerment program for two senior centers in Paterson, New Jersey, including field trips to its dispensary. The industry has many satisfied older customers. Liz Logan, 67, a freelance writer in Bronxville, New York, had grappled with sleep problems and anxiety for years, but the conditions grew particularly debilitating 2 years ago, as her husband was dying of Parkinson's disease. 'I'd frequently be awake until 5 or 6 in the morning,' she said. 'It makes you crazy.' Looking online for edible cannabis products, Logan found that gummies containing cannabidiol, known as CBD, alone didn't help, but those with 10 milligrams of THC did the trick without noticeable side effects. 'I don't worry about sleep anymore,' she said. 'I've solved a lifelong problem.' But studies in the United States and Canada, which legalized nonmedical cannabis use for adults nationally in 2018, show climbing rates of cannabis-related health care use among older people, both in outpatient settings and in hospitals. In California, for instance, cannabis-related emergency room visits by those 65 or older rose, to 395 per 100,000 visits in 2019 from about 21 in 2005. In Ontario, acute care (meaning emergency visits or hospital admissions) resulting from cannabis use increased fivefold in middle-aged adults from 2008 to 2021, and more than 26 times among those 65 and up. 'It's not reflective of everyone who's using cannabis,' cautioned Daniel Myran, an investigator at the Bruyère Health Research Institute in Ottawa and lead author of the Ontario study. 'It's capturing people with more severe patterns.' But since other studies have shown increased cardiac risk among some cannabis users with heart disease or diabetes, 'there's a number of warning signals,' he said. For example, a disturbing proportion of older veterans who currently use cannabis screen positive for cannabis use disorder, a recent JAMA Network Open study found. As with other substance use disorders, such patients 'can tolerate high amounts,' said the lead author, Vira Pravosud, a cannabis researcher at the Northern California Institute for Research and Education. 'They continue using even if it interferes with their social or work or family obligations' and may experience withdrawal if they stop. Among 4,500 older veterans (with an average age of 73) seeking care at Department of Veterans Affairs health facilities, researchers found that more than 10% had reported cannabis use within the previous 30 days. Of those, 36% fit the criteria for mild, moderate, or severe cannabis use disorder, as established in the Diagnostic and Statistical Manual of Mental Disorders. VA patients differ from the general population, Pravosud noted. They are much more likely to report substance misuse and have 'higher rates of chronic diseases and disabilities, and mental health conditions like PTSD' that could lead to self-medication, she said. Current VA policies don't require clinicians to ask patients about cannabis use. Pravosud thinks that they should. Moreover, 'there's increasing evidence of a potential effect on memory and cognition,' said Myran, citing his team's study of Ontario patients with cannabis-related conditions going to emergency departments or being admitted to hospitals. Compared with others of the same age and sex who were seeking care for other reasons, research shows these patients (ages 45 to 105) had 1.5 times the risk of a dementia diagnosis within 5 years, and 3.9 times the risk of that for the general population. Even after adjusting for chronic health conditions and sociodemographic factors, those seeking acute care resulting from cannabis use had a 23% higher dementia risk than patients with noncannabis-related ailments, and a 72% higher risk than the general population. None of these studies were randomized clinical trials, the researchers pointed out; they were observational and could not ascertain causality. Some cannabis research doesn't specify whether users are smoking, vaping, ingesting or rubbing topical cannabis on aching joints; other studies lack relevant demographic information. 'It's very frustrating that we're not able to provide more individual guidance on safer modes of consumption, and on amounts of use that seem lower-risk,' Myran said. 'It just highlights that the rapid expansion of regular cannabis use in North America is outpacing our knowledge.' Still, given the health vulnerabilities of older people, and the far greater potency of current cannabis products compared with the weed of their youth, he and other researchers urge caution. 'If you view cannabis as a medicine, you should be open to the idea that there are groups who probably shouldn't use it and that there are potential adverse effects from it,' he said. 'Because that is true of all medicines.'