BRAIN - 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.
GUT - Starts ageing at 55
A healthy gut has a good balance between harmful and 'friendly' bacteria. But levels of friendly bacteria in the gut drop significantly after 55, particularly in the large intestine, says Tom MacDonald, professor of immunology at Barts And The London medical school. As a result, we suffer from poor digestion and an increased risk of gut disease. Constipation is more likely as we age, as the flow of digestive juices from the stomach, liver, pancreas and small intestine slows down.
BREASTS - Start ageing at 35
BY their mid-30s, women's breasts start losing tissue and fat, reducing size and fullness. Sagging starts properly at 40 and the areola (the area surrounding the nipple) can shrink considerably.
BLADDER - Starts ageing at 65
Loss of bladder control is more likely when you hit 65. Women are more vulnerable to bladder problems as, after the menopause, declining oestrogen
levels make tissues in the urethra - the tube through which urine passes - thinner and weaker, reducing bladder support. Bladder capacity in an older adult generally is about half that of a younger person - about two cups in a 30-year-old and one cup in a 70-year-old.
LUNGS - Start ageing at 20
Lung capacity slowly starts to decrease from the age of 20. By the age of 40, some people are already experiencing breathlessness. This is partly because the muscles and the rib cage which control breathing stiffen up.
VOICE - Starts ageing at 65
Our voices become quieter and hoarser with age. The soft tissues in the voice box (larynx) weaken, affecting the pitch, loudness and quality of the voice.
A woman's voice may become huskier and lower in pitch, whereas a man's might become thinner and higher.
Aging Part I
