Krill oil costs more because it is supposed to absorb better. Across 64 randomised trials it produced no different result on any blood lipid — and the study the whole claim rests on had twelve men and a result that was not statistically significant.
Across 49 randomised trials, protein supplementation added 0.66 lb of fat-free mass. Real, and a fraction of what the tub implies. Without resistance training, two separate meta-analyses find it does nothing at all.
Eleven randomised trials found red light took nearly three inches off the waist and 7.8 lb off the scale — while the percentage of the body that was fat did not change at all. The reviewers grade their own evidence very low to moderate.
Cortisol is not a toxin that accumulates — when someone genuinely has too little, the treatment is 15 to 25 mg of hydrocortisone a day. The predecessor idea, adrenal fatigue, was reviewed across 3,470 articles and called a myth.
Two meta-analyses pooling 45 randomised trials found collagen improves skin hydration and elasticity against placebo. Half the trials in the larger one had missing outcome data, and 95% of participants were women.
Meditation and yoga lowered cortisol across 87 randomised trials, every one against an active control. They also lowered blood pressure, heart rate, inflammation and cholesterol — which is exactly why cortisol cannot be shown to be the lever.
Moon face is a real sign — of a condition affecting 1.8 to 3.2 people per million a year. And cortisol's link to belly fat, measured across 146 cohorts and 34,342 people, comes out at a correlation of 0.10.
A physiologist searched exhaustively for the study behind eight glasses a day and found none. The likeliest origin is a 1945 figure for total water — most of which was meant to come from food — and the nearest thing to a source says six.
Across 139,691 people in 17 countries, every 5 kg of missing grip strength came with 16% higher risk of dying — beating systolic blood pressure as a predictor. The same paper says nobody knows whether improving it changes anything.
A 2025 scoping review found ten regions called Blue Zones. Three are well characterised, one has fewer centenarians than average, and of Loma Linda it reports plainly: no studies have been conducted.