The study isn’t from Oxford. It’s from a team of Chinese scientists (likely in China) who used a large dataset collected in the UK.
The study is published in The Journal of Clinical Endocrinology & Metabolism, which the Oxford Academic collects and reproduces for their academic press.
It’s a real shame; Irvine has lots of great food, and it’s another large east-Asian population center within the LA-OC metro area, but it’s also so staunchly Republican that I can’t stand to watch local news down there.
That’s nothing against the university, though. I have family who got their degrees there, and I even took summer classes on campus once. I dig the school and it was my fallback when I applied for colleges (back when it was possible to have a fallback).