The average age for men fell from 71 to 68 and from 75 to 73 for women between 2007 and 2016, Public Health England said.
The shift is partly due to increased stroke rates among 40 to 69-year-olds – up from 33 per cent to 38 per cent in the period.
There has also been a drop in the proportion of the over-70s having strokes, in part thanks to health checks which focus more closely on stroke risk factors.
Prof Julia Verne, Public Health England’s director, told the BBC that the findings showed “everyone needs to be aware of the signs”.
“Calling 999 as soon as you see even one of the symptoms develop – in the face, arms and speech – is essential. Speedy treatment will help prevent deaths and disability,” she said.