Early, small, conflicting, or animal-only. Not actionable alone.
Five small trials gave collagen on its own against a dummy. Four found some hair measure better: slightly thicker strands in three, less shedding in one; the fifth reports thicker strands we could not check against its dummy. None enrolled people diagnosed with hair loss, and most of the other trials test mixtures. We rate it Preliminary.
Yes: a 3-ounce serving of shrimp carries about 161 mg of cholesterol, about as much as a large egg. In a feeding trial, two-thirds of a pound a day raised LDL 7.1%, about as much as two eggs did; in another, half a pound of prawns a day found no significant difference against crab sticks. No trial we found recruited people whose cholesterol was already high.
In the best trial we found, of 120 tired, otherwise healthy adults below 20 ng/mL, a vitamin D dose cut fatigue scores 2.5 points more than a dummy pill at four weeks, and the end scores were too close to call. A genetic study of 327,478 Britons found no clear link. Real deficiency brings aching bones and weak muscles.
A heavy night can lower testosterone for hours. Three weeks of about three beers a day cut it 6.8% in 10 men. In 7,938 men in population studies, drinkers' levels were no lower, and the pooled study that says otherwise rests on three rows whose comparison group averages 1,640 ng/dL.
Avocado oil's fat is close to olive oil's, which predicts lower LDL in place of butter. Its own trials are small: a meal study in 13 adults, and 12 weeks in 31 adults, 14 of them on avocado oil, in which cholesterol did not change significantly. Measured, the refined kind sold for high heat smoked before sunflower oil, and most bottles tested in 2020 were stale or mixed with other oils.
In people with type 2 diabetes, Denmark's national registry and three studies against other newly started diabetes drugs found a rare optic-nerve stroke called NAION diagnosed about twice as often on semaglutide: roughly one extra case per 10,000 people a year, Europe's regulator estimates. Other records studies, among them the largest against other drugs, found a smaller rise, no clear rise or less. Pooled trials are too small to settle it, and for people without diabetes the studies cannot tell. Sudden vision loss, or sight that worsens quickly, in either eye needs same-day care.
At 180/120 or higher, high blood pressure can cause a headache, and you should treat the pairing as an emergency. Below that the record conflicts: blood-pressure pills cut reported headaches by about a third in 94 trials, while Norwegians with higher readings were less likely to report headaches 11 years later, and 24-hour monitors did not find headaches arriving with higher readings.
Standing on a vibration plate makes older legs stronger than doing nothing, but not clearly stronger than ordinary exercise. For bone, the evidence conflicts: the three biggest randomised trials we found with results, 1,086 people, showed no clear gain at the hip or spine. In 20 trials a plate on its own took off no significant weight or fat, and ‘10 minutes equals an hour’ fails when measured.
Glycine before bed may help you sleep: in a sleep lab, 11 people fell asleep sooner on it than on a dummy powder, though 14 men in the maker's second sleep-lab trial, described in its patent, did not fall asleep significantly faster. The three published randomised trials add up to 37 people over one to four nights, each with the maker's staff among its authors. GlyNAC's anti-ageing case rests on one 24-person trial; a 114-person company trial found no significant rise in glutathione.
The video's first reference found a neck-artery wall 0.03 mm thinner after seven years of a Mediterranean diet, and called it slower progression. In a 1998 lifestyle trial, the narrowest point of the heart's arteries held its width on average while the comparison group's narrowed. Drugs that drove LDL cholesterol to about 60 mg/dL or below shrank coronary plaque by about one percentage point of artery volume.