At least 1 in 4 former NFL players had CTE at death; food logging tracks with weight loss; a cancer protein's second job — Morning Medical Update

At least 1 in 4 former NFL players had CTE at death

The estimate runs from 24.5% to 97.7%. Researchers say the true rate falls somewhere in between.

At least 24.5% of former National Football League players who died between 2016 and 2021 had chronic traumatic encephalopathy (CTE) at death, according to a retrospective cohort study published Aug. 25 in The BMJ. Researchers identified 878 former players who died in that window. Of those, 235 donated their brains and 215 showed CTE pathology.

Because the brains of the remaining players were not examined, the authors bracketed prevalence between 24.5% and 97.7% rather than reporting a single estimate. Among donors with CTE, 61.3% met clinical criteria for dementia, a figure that rose to 90.4% in those with Stage IV disease, the most severe form.

“Community brain bank studies have shown that CTE affects less than 1% of the general population,” said lead author Daniel Daneshvar, M.D., Ph.D., chair of physical medicine and rehabilitation at Mass General Brigham. CTE can be confirmed only after death, and brain donors are not a random sample, since families more often donate when symptoms were evident. The study does not establish how common CTE is among living players, and the authors cautioned against generalizing the findings to other levels of football or to other contact sports.

Food logging tracks with weight loss

Users who logged six or seven days a week lost 11.33% of body weight. The study was run by the app's own team.

Adults using a commercial food-logging app who tracked meals six or seven days a week lost 11.33% of body weight over six months, compared with 6.84% among those who tracked fewer than two days a week, according to a retrospective cohort study of 5,132 MyNetDiary users published Aug. 13 in the Journal of Medical Internet Research. Each additional tracking day per week was associated with 35% higher odds of losing at least 5% of body weight, the threshold clinical guidelines tie to meaningful health improvement.

Participants who logged just two or three days a week still lost 7.35%, and more than half reached the 5% threshold. Users with logging streaks longer than 90 days lost 11.55% of body weight, compared with 4.21% among those whose longest streak ran a week or less. Across the full cohort, the average loss was 9.3 kilograms, or about 20.5 pounds.

The study is observational and cannot establish causation. The cohort was an engaged subset representing about 1.2% of new signups, and medication use, including glucagon-like peptide-1 (GLP-1) receptor agonists, was not measured. It was also conducted by MyNetDiary's own team; first author Sergey Oreshko is the company's cofounder and CEO. Conflicts of interest are disclosed in the paper, which was published alongside an anonymized replication dataset.

A cancer protein's second job

BRAF inhibitors already approved for cancer reduced pain sensitivity in preclinical models of nerve injury.

BRAF, a protein best known for its role in cancer, appears to drive chronic pain after nerve injury, according to preclinical research from the University of Texas MD Anderson Cancer Center published Aug. 24 in Science Signaling. After nerve injury, BRAF moved from peripheral sensory neurons to their terminals in the spinal cord, where it activated signals that increased NMDA receptor activity, amplifying pain signaling.

The BRAF inhibitor vemurafenib and the MEK inhibitor selumetinib reduced sensitivity to touch, pressure and heat in models of nerve injury without altering responses in uninjured models. Deleting the Braf gene produced less persistent pain sensitivity, while activating BRAF directly caused pain sensitivity in models that had no nerve injury. Researchers also found a correlation between BRAF signaling proteins and NMDA receptors in human spinal cord samples.

Because BRAF inhibitors are already approved in oncology, existing drugs could potentially be repurposed for neuropathic pain, which responds poorly to conventional analgesics, the researchers said. The results are preclinical, and dosing, delivery and side effects require further study before human trials. The work was co-led by Shao-Rui Chen, M.D., and Hui-Lin Pan, M.D., Ph.D., of the department of anesthesiology and perioperative medicine.