This week in health, graded

A viral gut reset for stiff knees has no trial we could find behind it

A viral reel sells a 14-day gut reset for aching knees. We found no trial that tested a gut reset on knees. The 2019 OARSI guideline's core knee care is education, exercise and, for people carrying extra weight, weight loss. Ask your clinician or a physiotherapist what suits your knees.

Supervised heavy lifting raised bone density in postmenopausal women

In the LIFTMOR trial, 101 postmenopausal women with low bone mass did 8 months of supervised heavy lifting plus impact training and gained lumbar spine bone density, 2.9 percent, while a gentle home-exercise group lost it, minus 1.2 percent. It is one trial that measured bone density, not fractures. Orthopedic surgeon Dr Vonda Wright summarizes the approach as lift heavy, add impact, train balance. The trial was closely supervised, so if you have osteoporosis, osteopenia or a past fracture, talk to your clinician before starting heavy or impact training.

Winter vitamin D did not lower heart attack, stroke or cancer in a 25,871 person trial

Vitamin D is pushed every winter, but in the VITAL trial, 25,871 US adults aged 50 and over, not selected for low vitamin D, taking 2,000 IU a day for about five years saw no drop in cancer, heart attack or stroke. It still matters if you are genuinely low, so the move is a blood test first and supplementing with your clinician if the number calls for it, not a bottle bought on the season.

Eating MSG does not raise the glutamate level in your brain

A viral post warns that MSG floods your neurons with glutamate. A review of the physiology by a University of Pittsburgh neuroscientist concludes it does not: the blood-brain barrier restricts dietary glutamate, so eating MSG does not raise the glutamate level in your brain. This rests on a narrative review rather than a large trial. For most people the evidence gives no reason to avoid it; if one specific food reliably gives you headaches, track it and mention it to a clinician.

High-dose fish oil raised atrial fibrillation risk across 7 trials

Fish oil is sold as heart protection, but pooling 7 large trials, omega-3 supplements were associated with more atrial fibrillation, an irregular heartbeat: about 12 percent more at 1 gram a day or less, and 49 percent more in trials testing more than 1 gram a day, in people averaging 65 years old. If you take an omega-3 supplement, ask your clinician whether it suits you, and do not stop a prescribed one without asking.

Vibration plates alone did not cut body fat across 20 trials

The plate that shakes while you stand on it is sold as a shortcut to fat loss. Across 20 randomized trials with 585 people, weight and body fat did not change meaningfully overall; a subgroup aged 50 and over showed a possible fat reduction that needs confirming. The review did not compare plates with other exercise, but for fat loss, regular activity and what you eat have the stronger evidence base.