Scientific American has obtained the list of specific studies ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
November 20, 2025—Could AI "griefbots" help us mourn loved ones? Plus, no link found between fluoride in water and cognitive loss, and NASA captures new views of the 3I/ATLAS comet. All that below, but first, some breaking news. —Andrea Gawrylewski, Chief Newsletter Editor | | - Grants for at least 383 clinical trials have been terminated by the National Institutes of Health since February, affecting 1 in 30 of all clinical trials and some 74,000 patients. The cuts include more than 100 studies on cancer treatments, 97 on infectious diseases, and more. Scientific American has obtained the list of specific studies, read more about them here. | 2 min read
| | Amanda Montañez; Source: "Clinical Trials Affected by Research Grant Terminations at the National Institutes of Health," by Vishal R. Patel et al., in JAMA Internal Medicine; Published online November 17, 2025 (data); clinicaltrials.gov (trial information) | | NASA/Southwest Research Institute | | A massive, decades-long study has now found no link between ingesting recommended levels of fluoride and lower cognitive skills in the U.S. Researchers analyzed data from a national study cohort that started with more than 26,000 participants in 1980. About half were a part of a 2021 follow-up. The researchers estimated their fluoride exposure from birth to 12th grade, then compared that with their standardized test scores. Children who ingested recommended levels of fluoride performed slightly better than those who were never exposed to sufficient levels. They also showed no difference in cognitive skills in adulthood.
Why it matters: There is a debate in the U.S. as to whether fluoride should be included in public water supplies, despite evidence of the mineral's health benefits. Several cities and states are re-evaluating their inclusion policies, with some places, such as Utah, having already removed it. As the first long-term study of its size that looks at this link in the U.S., it could shape policy decisions, says pediatrician Susan Fisher-Owens, who was not involved in the study.
What the experts say: Any policy assessment needs to account for both the benefits and potential harms of fluoridation, says epidemiologist David Savitz, who was not involved in the new study. But, he adds, the evidence that supports the benefits of fluoridation in the U.S. is stronger than any evidence of potential harms. —Andrea Tamayo, Newsletter Writer
| | Would you like to talk to an AI version of a dead loved one? Tech start-up companies around the world have started offering "griefbots" as tools to help people mourn and process loss. Few scientific studies have assessed whether these tools are effective, and experts have wide-ranging opinions on the usefulness or potential danger of the technology. The pros: Might a griefbot be therapeutic? For patients who want to resolve relationships with deceased relatives, Robert Neimeyer, a therapist and professor at the University of Memphis, sometimes asks people to imagine a deceased loved one sitting next to them; but the AI version might be open and communicative, without the same hangups the real-life person may have. Some patients might work through their feelings with the AI ghost and find new insights or emotions to discuss with a human therapist. Others may simply enjoy reconnecting with any version of their loved one. The cons: When a person dies, the brain must learn that their loved one is no longer there, which is slow and often gradual. The relationship to memories of that person evolves, from pain to solace or wisdom. For some, the risk of a lifelike interactive chatbot is that it could make the past too attractive to let go.
The future: Digital ghosts won't necessarily be AI clones of dead people, says Amy Kurzweil, an independent scholar. These bots could be original characters, built on historical information, yes, but also on the thoughts and feelings of the user. She imagines a future in which anyone might create all kinds of digital ghosts depending on what they need. | | | | |
- Melina Maldonado Sandoval (center right), a fisher in the Lázaro Cárdenas Yoreme-Mayo community, helps a research center to study the impact of industrial pollution on marine life in Ohuira Bay, Mexico. She and other local community members have founded the campaign group Aquí No ("Not Here") to fight the proposed construction of a nearby ammonia production and storage plant, which could devastate local marine life. "We will continue to defend our bay, tooth and nail, because it is our home, our medicine and our future," she says. (Nature | 3 min read)
| | Mary-Frances O'Connor, a professor of clinical psychology at the University of Arizona, has used MRI scans to study the effects of loss on the brain. In her research, which writer David Berreby covers in his feature on AI griefbots, she's found that the brain encodes love as "everlasting." I found this fascinating. Other than taxes, the one thing we know is true in life is that we all die. And yet our brains have evolved an unending attachment to mortal, and fragile, fellow creatures. It seems counterintuitive, until you consider that our social relationships help us survive. | | Would you want to talk to an AI version of a dead loved one? I'm curious what you think. Email me: newsletters@sciam.com. See you tomorrow. —Andrea Gawrylewski, Chief Newsletter Editor
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