Protein plaques in the brain may be caused by failing mitochondria Sebastian Kaulitzki/Alamy
IF YOU own a car, you will have noticed the engine getting less efficient with time. The further you drive it, the more fuel it takes to make the same journey – until, eventually, it becomes so underpowered that it needs a physical push to climb even a gentle hill.
Now, it is emerging that much the same is true of the human brain. Microscopic structures called mitochondria, found in every brain cell, are quite literally the engines of our thoughts and feelings. As we age, they find…