The Daily Star's FREE newsletter is spectacular! Sign up today for the best stories straight to your inboxBrits don't begin to take their health seriously until they're approaching their 40s, new research suggests.A poll of 2,000 adults found 42% only start taking more care from the age of 39 as they felt less energetic, while one in five started to feel breathless going upstairs.Others became more concerned after reaching 'milestone birthdays' (20%), having a doctor comment on their wellbeing (9%) or when a family member fell ill or passed away (16%).It also emerged 28% of adults believe they need to take their health more seriously than they currently do, with 31% wishing they had done so while they were younger.Dr Sarah Brewer, medical.