There's no denying the ticking of a woman's biological clock - but men are not immune, either. French doctors have found that the quality of sperm starts to deteriorate by 35, so that by the time a man is 45 a third of pregnancies end in miscarriage. Here, with the help of leading clinicians, Angela Epstein identifies the ages when different parts of the body start to lose their battle with time.
Starts ageing at 20
As we get older, the number of nerve cells - or neurons - in the brain decrease. We start with around 100 billion, but in our 20s this number starts to decline.
By 40, we could be losing up to 10,000 per day, affecting memory, co-ordination and brain function.
In fact, while the neurons are important, it's actually the deterioration of the gaps between the brain cells that has the biggest impact, says Dr Wojtek Rakowicz, a consultant neurologist at Imperial College Healthcare NHS Trust in London.Read more...