UK universities and International Science Olympiads

Do British unis care about achievements at ISOs?
For example if I wanted to study medicine at Cambridge, and I had a silver medal from International Biology Olympiad , how would this affect my chances of getting in?

That, with the addition of outstanding grades and countless hours of work experience (you need experience for medicine) should guarantee you an interview…

They care mostly about BMAT scores. Also if you’re international there are extremely few places for medicine.