October 4, 2017

Slip, slop, slap

From Stuff, the front-page link:


As Betteridge’s Law of Headlines implies, the answer is “No.” Even the vendor doesn’t make a claim like that.

The story says (with the advertising redacted)

The key ingredient in the capsules is 100mg of … a blend of grapefruit and rosemary extracts. An independent lab trial of [the stuff] in Italy in 2015 found the onset of sunburn was delayed by 30 percent after two months of daily use.

It appears to be still-unpublished study. According to an advertising white paper,  it’s actually better than a lot of nutraceutical research: it was blinded and had 35 people in each group.  If we assume there aren’t any hidden problems, the study says that people who take this stuff daily for a couple of months end up needing about 30% more UV light to get a mild sunburn.

That is, the optimistic view is we’re looking at the equivalent of SPF 1.3 sunscreen.


Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient

See all posts by Thomas Lumley »