As a neurosurgeon, Henry Marsh has spent several decades making people’s brains better (and occasionally, as his memoirs document with breathtaking honesty, making them worse). But that job involved removing tumours and patching up the aftermath of serious head traumas. Keeping a brain in perfect health is an altogether different matter, not least because we understand so little about it.
A couple of years ago, the now 73-year-old Marsh agreed to have his own brain scanned. He was not overly worried about what it might show. He exercised well, stayed mentally active and was not displaying any significant signs of cognitive decline. “But it was slightly shocking, because my brain looked rather elderly,” he says. “I shouldn’t have been surprised because I was 70 years old! But it was rather scary.”
