Semaglutide linked to lower predicted dementia risk

tdlr: This is a Novo Nordisk-funded study focusing on predictive biomarkers rather than real-world dementia cases. Novo Nordisk's actual dedicated clinical trials for Alzheimer's completely failed to show that semaglutide stops cognitive decline. "A predictive biomarker is like a "check engine" light on your dashboard. It warns you that there is a risk of a future problem. In this study, the researchers only checked if the drug turned off the "check engine" light (by measuring blood proteins), rather than testing if the car was actually driving properly (by testing the patients' actual memory and brain function)." Always do FIRST analysis on studies. Or have AI do it for you. I used Gemini to dig into this: "Novo Nordisk funded this study, and several of the researchers are employees or minor shareholders. While corporate funding doesn't automatically mean the data is fabricated, it does mean the company is highly motivated to find and publish data that makes their blockbuster drug (semaglutide, marketed as Wegovy, Ozempic, and Rybelsus) look like a preventative treatment for a wider range of conditions, expanding its market and driving up profits." "Funding: The study was funded by Novo Nordisk A/S. Investigation: Researchers conducted a post hoc analysis using data from the randomized, placebo-controlled SELECT trial. They applied the Dementia SomaSignal Test (dSST)—a 25-protein risk score—to non-fasted serum samples collected at baseline and at week 104 to estimate 5-year and 20-year all-cause dementia risk in patients receiving semaglutide (2.4 mg) versus a placebo. Results: Semaglutide significantly attenuated the progression of the dementia risk signature. Compared to the placebo group, the 5-year predicted risk increased 2.5-fold less (a 26.0% lower predicted event rate) and the 20-year risk increased 1.67-fold less (an 8.8% lower rate). Semaglutide also lowered the odds of patients moving into a higher dementia risk category by 36%. Subjects: The analysis included 2,970 older adults aged 65 and older (mean age of ~69.7 years) who had overweight or obesity and cardiovascular disease, but no history of diabetes. The cohort consisted of 814 women (27.4%) and 2,156 men (72.6%). Time: The study evaluated data over a 104-week (2-year) follow-up period. The analysis was published on August 8, 2026." And then map the weakness to each respective letter if you want to dig deeper.

So has anyone managed to separate the effects of semaglutide from the effects of weight loss? If this is caused by the weight loss, it is a little disappointing that public health didn't act quicker - lots of people have been overweight for a century now, so literally 10's of millions of people could have been saved from dementia had action been taken 100 years ago.

I'm a big semaglutide proponent after being on it for a year. I know research says it helps with inflammation, arthritis (separately from weight reduction), and all sorts of magical things. I lost 40 pounds in a year(230 to 190) at age 50. Great! I also went from being active and fat(weightlifting with some cardio) to basically having no energy. In the last year I've had arthritis appear in several joints. I'm awake several times a night to pee(yeah, prostate is acting up but I still void completely. The semaglutide is like a diuretic for me at night.). I get waves of hypoglycemia like feelings where I feel weak and spaced out. I'm afraid to get off of it because now my joints can't handle the extra weight. My doc recommended going to every other week now that my BMI is normal but as far as I can tell that advice isn't backed up by any research. Anyway, it's a powerful drug that works well but is not without side effects.

If you're overweight or especially if you're T2D I highly encourage you to discuss GLP-1 with your doctor. If you're T2D then get research retatrutide which looks to be an actual cure for T2D by clearing liver fat. It should be released early next year but research-use is available and what everybody is taking. Companies like finnrick do public testing of research peptides and a good place to gather names.

I'm a strong proponent of GLP1. But a change in one marker is at best an okay signal. But the only thing one cares about is real changes in rates. Who cares about markers that don't translate to real clinical outcomes. That's the whole damn problem with everything from stupid "this makes you younger" claims and the tragedy that is the history of Alzheimer research. I wish they compared straight-up weight loss without disease. In this specific population, the bias has a known direction: unintentional weight loss in older adults is a well-documented dementia prodrome = weight starts dropping years before diagnosis. So placebo-arm weight losers are enriched for people already on the downward trajectory, and any comparison matched or adjusted on BMI change-diff inherits that, making the drug look better than it should in this study design. And the 5-year OR 0.74, and no BMI-adjusted coefficient is given for it. The 5-year calibration is dominated by near-term inflammatory/metabolic pathways — exactly what weight loss moves, so it plausibly attenuates much more than 28%. I think the conclusion is not warranted at all: that semaglutide does more than its weight loss explains, not the same or less. Which is also the commercially valuable claim. And note that Novo funded the study, AND two authors are Novo employees/shareholders. In short, I like GLP1s, but I'm not convinced by this study that GLP1 treatment reduces dementia incident rates meaningfully compared to normal health weight loss.