The details: Participants took a brief cold shower partway through. Average levels of cytokines, the immune system's signaling proteins, changed little, though some tracked how much body temperature rose. "This may indicate that sauna bathing mobilizes additional white blood cells into the bloodstream from tissues," said researcher Ilkka Heinonen. Published in the journal Temperature.

Yes, but: The study measured one session, and the changes were short-lived. It didn't test whether regular sauna use lowers illness risk, and the cold shower means heat alone wasn't isolated. Sauna temperature, the sex breakdown and funding weren't reported in the summary.

The details: The data came from Finland's long-running Kuopio Ischaemic Heart Disease Risk Factor Study, with diets logged in 4-day food records from 1984 to 1989. Dairy protein was linked to lower testosterone and lower SHBG, a protein that carries testosterone in the blood; meat protein was linked to lower SHBG but not total testosterone. Results were adjusted for age, BMI and lifestyle. Published in the International Journal of Food Sciences and Nutrition.

Yes, but: It's a cross-sectional snapshot, so it can't show cause; the diet data are decades old, and the differences were small. Lead author Wynne-Ellis said "it is not possible to infer whether these differences have implications for health." Funding wasn't reported in the coverage.

The details: The recall covers the multi-capsule box (UPC 868592000002) and the single pack (UPC 868592000040). It wasn't sold at corporate GNC stores. GNC's third-party testing flagged the product, and buyers can return it to GNC for a refund. The notice was posted on the FDA's website Oct. 24.

Yes, but: No adverse events had been reported at the time of the notice. Talk to your doctor about ED treatment options.

Wall squats and blood pressure. In a 100-person randomized trial in BMJ Open Sport & Exercise Medicine, adults with systolic pressure of 120 to 140 who did four weeks of isometric wall-squat training and kept it up three times a week saw systolic pressure drop about 14 points by week 8; those who stopped lost the gains. ScienceDaily

Daylight and dementia. In 87,577 adults who wore wrist light sensors and were followed a median 8.1 years, average daytime light above 1,000 lux was linked to a 16% lower dementia risk; the authors said it doesn't show daylight prevents dementia. ScienceDaily

Retatrutide and sleep apnea. In two 80-week phase 3 trials of 691 people in the NEJM, the experimental weight-loss drug retatrutide cut sleep apnea events by about 20 to 34 per hour vs. about 10 on placebo; the lead author said there's no evidence of an independent direct effect on breathing control. It isn't approved. Medical News Today

Low-carb and LDL. In a secondary analysis of a 193-person Norwegian trial in eBioMedicine, a very low-carb diet high in saturated fat raised LDL 5% to 10% but not apoB, and coronary calcium didn't differ at 12 months; an author said the LDL rise can't necessarily be considered insignificant. News-Medical

Fiber and knee pain. In a 6-week, 117-person trial in Nutrients, a daily inulin fiber supplement and physio exercises each reduced knee osteoarthritis pain; the authors said fiber shouldn't replace exercise. ScienceDaily