A 20-person study links ultra-processed food to depression, as Science turns to women's health

The study, from UC San Francisco and funded by the National Institutes of Health, is described by its authors as the first to compare depression symptoms in the same participants before and after they moved away from their usual ultra-processed diet. It appeared in JAMA Psychiatry on 23 September, according to a summary published by ScienceDaily on 1 October.

Twenty people took part. Average age was 44 and 70% were female. Fourteen also had anxiety, and every participant had a high BMI plus at least one metabolic disorder such as hypertension, diabetes, or elevated LDL cholesterol. Participants cut their intake of ultra-processed foods by more than 85%, and anxiety scores improved modestly alongside the depression measures.

Senior author Andrew Krystal, a professor in UCSF's departments of Psychiatry and Behavioral Sciences and Neurology, said the pilot "successfully established the viability of carrying out this research in a larger-scale trial." The team plans a larger phase 2 study, with enrollment expected to begin soon.

What the gut has to do with mood

Corresponding author Nyasha Chagwedera, who founded the UCSF Metabolic and Mental Health Program, offered a mechanism rather than a cure. "Reducing the amount of ultra-processed food in our diet can be challenging, because it's highly palatable, cheap, and convenient," she said. "Ultra-processed food triggers dopamine, the pleasure hormone, which promotes craving. Food companies work with scientists to find just the right amount of sugar, salt, and fat that make you want to eat more and more."

Her hypothesis centers on what she called a "leaky, out-of-balance gut." Under that idea, ultra-processed products damage the protective lining of the gut, and that damage creates low-grade chronic inflammation that either causes depression directly or makes people more vulnerable to it. "In other words, junky processing may harm your gut in ways that ripple up to your brain," Chagwedera said.

ScienceDaily notes the study is small and the findings preliminary. That caveat matters, because the same week produced a much larger piece of evidence about how diagnoses shift over time, and it points in a different direction.

A Danish study covering more than 2.1 million children and adolescents found that young people diagnosed with ADHD or autism now resemble the general population more closely than those diagnosed a decade earlier. Published in JAMA Psychiatry and led by the Barcelona Institute for Global Health with Aarhus University, it compared more than 71,000 diagnosed young people between 2012 and 2022 against more than 713,000 who had received neither diagnosis.

The gap on low birth weight is the clearest illustration. At the start of the period, children born with low birth weight were 54% more likely to later receive an ADHD or autism diagnosis. By the end, that difference had fallen to 17%. Similar declines showed up for premature birth and several measures of socioeconomic disadvantage.

"The key message is not that these risk factors are no longer important," said Magnus Elias Tarp, a PhD student at Aarhus University and first author of the study. "What we found is that people diagnosed in recent years resemble the general population more closely than those who received the same diagnoses a decade ago."

Science gives women's health a dedicated issue

On Thursday, the journal Science published a special issue on women's health, edited by an all-female team: Yevgeniya Nusinovich, Sacha Vignieri, Joana Osório, and Sarah Ross. STAT reported on 1 October that the editors named political attacks on women's rights and health care, plus funding cuts to research in the area, as urgent motives for the issue.

"The importance of doing clinical trials specifically in women has gained recognition over the years, and it's something that should continue to be elevated, including as research funding cuts are targeted at this and other women-specific research, threatening the quality of women's future healthcare," the editors said.

The issue's reviews cover sex-dependent biological differences beyond reproduction, the role of XX and XY chromosomes in aging and disease, and the state of menopause research. One review notes that women experience functional pain at roughly twice the rate of men, with persistent pelvic pain often becoming debilitating. "Women are desperately waiting for concrete answers that might help eliminate the common 'all in your head' approach to their illnesses," the review's authors wrote.

Nusinovich, a senior editor at Science, drew a line between reproductive and post-reproductive research, saying the focus of the latter is not on improving reproductive success but on a woman's own health.

Women experience functional pain at about twice the rate of men, and the Science review flags a deficit in efforts to understand female pain.

That deficit is the backdrop for a separate line of work on wearables. Researchers at Mount Sinai have used wearable AI to forecast prolonged sitting in women with chronic pelvic pain, according to a study covered by Medical Xpress on 30 September and by Digital Journal on 1 October. The underlying work on forecasting sedentary bouts, aimed at on-device learning and real-time deployment, was published in a Nature journal on 30 September.

The broader digital health funding picture is mixed. Endpoints News reported exclusively on 1 October that Parakeet Health, a startup that uses AI to call, text and email patients, raised $10 million. The same outlet reported that insurer startup Devoted Health raised nearly $1.2 billion after enrolling hundreds of thousands of new senior members.

Not every dollar is going toward care. CNBC reported on 1 October that the Blue Cross Blue Shield Association estimated hospitals' use of AI-assisted medical coding contributed close to $1 billion, or $942 million, in additional costs for its health plans between 2023 and 2025. BCBSA said roughly 70% of that total, or $653 million, was tied to additional diagnoses that came without a change in care, according to Luke Chalker, the association's senior vice president of product and data science.

Chalker stopped short of blaming AI for the whole increase. "While multiple factors contribute to coding intensity, the findings suggest AI-enabled coding and documentation tools are playing a role," he told CNBC. Christopher Whaley, a health economist at Brown University who studies hospital coding, said AI appears to be "accelerating, and in some sense making it easier to capture, the existing and underlying billing incentives that are in the system," while noting that in many cases the additional diagnoses are legitimate and simply were not captured before.

Two other data points from the same 24-hour window sit further from the clinic. The CDC's National Center for Health Statistics proposed an overhaul of the National Health Interview Survey in August that would cut the adult questionnaire from 482 questions to 150, removing items on hearing aids, fatigue, cognition, and mobility supports such as wheelchairs and scooters. STAT reported on 1 October that advocates warn the change would undercount people with intellectual and developmental disabilities, a group a recent paper co-authored by CDC statisticians suggests may already be missed at a rate of 75%. An HHS spokesperson declined to explain why the disability questions were struck, but indicated the changes were driven by a push to lower data collection costs.

In Germany, the federal certificate of conduct became available as a PDF delivered to the BundID mailbox from 1 October, at the same 13 euro fee as the paper version, with a qualified electronic seal and QR code for verification. Heise reported that a BundID account, an ID card with the online function, and an NFC-capable smartphone are required, and that the Federal Office of Justice is still fixing verification-app problems on some Samsung models.

For the wearable and nutrition research, the through-line is the same one the Science editors identified: the evidence base is thinner than the enthusiasm. A 20-person crossover study and a wearable forecasting model are early signals, not settled science, and both arrive in a funding climate the Science editors describe as actively hostile to women-specific research.