“Risk cut by 50 %” can mean 1 person in 1,000.
Relative risk compares groups: if a disease drops from 2 to 1 per 1,000, that's “50 % less”. In absolute terms it's 0.1 percentage points. Headlines almost always use the relative figure because it sounds bigger. The honest question is: how many people out of 1,000 does this really affect?
Useful: For every percentage in health news, ask: percent of what?
Source: en.wikipedia.org