Cancer infections, breath, AI shame: three September studies on health and the body

CBC News reported on the study on 29 September. Researchers at the International Agency for Research on Cancer (IARC), an arm of the World Health Organization, estimate that infections caused 2.3 million new cancer cases worldwide in 2024, or 12 per cent of all new cases. The paper appeared on Monday in The Lancet Oncology.

Gary Clifford, a cancer epidemiologist and study co-author based in Lyon, France, told CBC that the science has moved. "There's been new infectious agents identified in this time as being cancer-causing, and even the infectious agents that we knew about in the past, the evidence has increased about the number of different cancers that they can cause," he said, according to CBC.

What the numbers say

The largest single contributor was the bacterium Helicobacter pylori, which can raise the risk of stomach cancer and accounted for 760,000 cases, predominantly in eastern Asia. Human papillomavirus followed close behind at nearly 750,000 new cases globally, with high rates in sub-Saharan Africa. HPV causes 100 per cent of cervical cancer cases and is also linked to anal, vulvar, vaginal, penile and some head and neck cancers. Hepatitis B and hepatitis C were linked to a significant number of liver cancer cases. For the first time, the researchers expanded their list of cancer-causing infections to include 16 additional ones, among them HIV, linked to cervical cancer, and Merkel cell polyomavirus, a very rare virus that can lead to an aggressive form of skin cancer.

Epstein-Barr virus was tied to about 260,000 cases in 2024, including nasopharyngeal cancer, some gastric cancers and Hodgkin's lymphoma. "That's quite a big burden of cancer caused by Epstein-Barr virus that was not counted in the past, but is now recognized," Clifford said, per CBC. EBV is also a key risk factor in multiple sclerosis, and unlike some of the other infections in the study, there is no vaccine or antibiotic treatment for it. "The fact that we're seeing Epstein-Barr has caused all these chronic diseases, it's increasingly becoming a target that people need to focus on for prevention," he said.

The authors first established which infections cause cancer, then calculated what fraction of those cancers can be tied to specific infections, and applied those fractions to global databases of new cancer cases. That is a modelling exercise, not a count of individual patients, and the estimates carry the uncertainty of the underlying registries. The regional split is wide. High-income countries that built screening and vaccination programmes over recent decades are doing much better than lower- and medium-resourced countries where access to prevention and treatment is limited. "We really still have a lot of work to do implementing things that we know work and we've known for a long time but haven't really made it into all populations in the world," Clifford said.

In North America the burden is much lower, but H. pylori and HPV remain the most common sources. In Canada, according to a 2019 study cited by CBC, the rate of cancers attributable to infections was estimated at four per cent. Karena Volesky, an epidemiologist in Montreal who led the Canadian research team while at McGill University, told CBC the new global figures show how important each of the 12 infections is.

A 41-millisecond gap between exhaling and inhaling

On the same day, Northwestern University put out a very different kind of result. Neuroscientists there found that response speed on an exhalation is faster than on an inhalation by an average of 41 milliseconds, roughly one twenty-fifth of a second. Response speed during the pauses between breaths is also faster than inhalation, by 21 milliseconds. According to the university's release, published on 29 September, it is the first experiment to measure response speed during all phases of respiration, including the pauses between breaths.

The paper, "Response speed is modulated by respiratory phase," appeared in the journal iScience, published by Cell Press. Ken Paller, the James Padilla Professor of Psychology at Northwestern, is senior author; neuroscientist Erika M. Yamazaki, a former member of Paller's lab, is lead author. Thirty-five adults aged 18 to 33 completed a Psychomotor Vigilance Task, pressing the space bar as quickly as possible when a red square turned yellow, while wearing a simple device under the nostrils to measure airflow. Each participant did the task twice, once before and once after a nap or an eight-hour sleep in the lab.

"By using a tangible and easy to understand task, we were able to show the relationship between respiration and cognition, which I hope people in a range of fields will find application for," Yamazaki said in the release. "Study of the brain and body connection is still a new field of research, which makes the study findings all the more exciting." Paller was careful about the mechanism. "This study documents an important link between respiration and the brain systems for responding to environmental events," he said. "We don't yet know exactly how they are linked, but we suspect neurophysiological efficiency, because other studies have shown that various brain oscillations are synchronized with the rhythms of one's breathing."

Paller's lab is now running related research funded by the National Institutes of Health and led by Yamazaki, focused on sleep apnea, the harmful breathing pauses during sleep that are often under-diagnosed and inadequately treated. The researchers hope noninvasive strategies for improving sleep, an approach sometimes called sleep engineering, will counter some of the consequences of poor sleep. The sample here is small, 35 people, and the effect is tens of milliseconds. It is a lab finding about the timing of a keypress, not a wearable product. But it sits in the same research space as the cardiopulmonary monitoring work that has been filling journals this month, and it points at the same question: how much of the body's rhythm can be measured unobtrusively, and what does that measurement actually predict.

AI use without guidelines, and the shame that follows

The third September study is about behaviour, not biology. Nieman Journalism Lab reported on 28 September on a paper titled "Guidance over guidelines? Unpacking the uses and concerns of generative AI in communication science," published in Information, Communication and Society. Researchers from National Yang Ming Chiao Tung University in Taiwan, the University of Amsterdam and Utrecht University surveyed more than 1,100 communication scholars from 77 countries and held four focus group discussions. The study found a disconnect between what researchers believe and what they do.

Nearly 70 per cent of respondents had already used generative AI in at least one research-related task, but most considered AI use inappropriate for most research-related tasks. Just over half said using AI for writing texts (55 per cent) and generating code (50.4 per cent) were appropriate use cases, and the authors note that participants did not reach consensus on what counts as ethical use. Without institutional guidance, researchers set their own standards, and that produces stigma.

The authors describe a transparency paradox: researchers may feel an ethical obligation to disclose generative AI assistance while fearing that disclosure will make their work look less authentic or credible. "While such hesitation is understandable given that reporting genAI use might reduce the chances of publication, it ultimately hampers open discussion about how these tools can be used ethically and responsibly in research," the study says. "Transparency is therefore essential, as effective and meaningful guidelines can only be developed when we understand when and how genAI is being used." The authors recommend that the communication research community, including individuals, institutions and journals, build a disclosure-positive culture by requiring researchers to disclose the stages of their work at which they used generative AI. "Simply forbidding the use of genAI, or pretending that it is not being used, is neither sustainable nor constructive," they write. Hannes Cools, one of the researchers, summarised the survey on Bluesky on 28 September, describing it as the first systematic, field-wide, international empirical investigation of generative AI practices in communication research.

What ties them together

None of these three studies is about a consumer device, and that is the point worth noting on a day when the health-technology headlines are dominated by wearables, sensors and AI triage tools. Two of the papers are about things the body does on its own, an infection that turns into cancer years later, a breath that shifts reaction time by milliseconds. The third is about how professionals behave when a new tool arrives faster than the rules for it.

The infection paper carries the largest policy consequence, because it points at vaccines, antibiotics and screening programmes that already exist. The respiration paper carries the smallest immediate consequence, because it is a 35-person lab experiment with no product attached. The AI paper carries the most awkward one, because it suggests that the gap between official guidance and daily practice is currently being filled by silence. What the three share is a methodological caution. The cancer estimates are modelled fractions, not registrations. The respiration effect is a mean across a small sample. The AI survey is self-reported. All three are the kind of result that gets flattened into a headline, and all three come with caveats the authors themselves put on the record.

For readers tracking digital health specifically, the useful signal this week is not a new gadget. It is that the evidence base for the body's own signals, breath, infection, immune response, is still being assembled, and that the professional norms for the tools used to analyse it are still being argued over.