When your body really starts aging

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.
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.

These tiny gaps between the end of one brain nerve cell and another are called synapses,Their job is to ensure the flow of information from one cell to another, and as we age we make fewer.

• 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.

Although breast cancer risk increases with age,it's not related to physical changes in the breast, More likely, says Gareth Evans, breast cancer,specialist at St Mary's Hospital, Manchester,
our cells become damaged with age - as a
result, the genes which control cell growth can
mutate, causing cancer.

• BLADDER
Starts ageing at 65
Loss of bladder control is more likely when
you hit 65.
The bladder starts to contract suddenly, even
when it's not full.
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.
This causes more frequent trips to the loo,
particularly as poor muscle tone means the
bladder may not fully empty. This in turn can
lead to urinary tract infections.

• 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.
It's then harder to work the lungs and also
means some air remains in the lungs after
breathing out - causing breathlessness.
Aged 30, the average man can inhale two pints
of air in one breath. By 70, it's down to one.

• 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.

• EYES
Start ageing at 40
Glasses are the norm for many over-40s as
failing eyesight kicks in - usually long-
sightedness, affecting our ability to see objects
up close.
As we age, the eye's ability to focus
deteriorates because the eyes' muscles
become weaker, says Andrew Lotery,
professor of ophthalmology at the University
of Southampton.

• HEART
- Starts ageing at 40
The heart pumps blood less effectively around
the body as we get older.
This is because blood vessels become less
elastic, while arteries can harden or become
blocked because of fatty deposits forming on
the coronary arteries - caused by eating too
much saturated fat.
The blood supply to the heart is then reduced,
resulting in painful angina.
Men over 45 and women over 55 are at
greater risk of a heart attack.
A recent study by Lloyds Pharmacy found the
average person in the UK has a 'heart age' five
years older than their chronological age,
probably due to obesity and lack of exercise.

• LIVER
Starts ageing at 70
This is the only organ in the body which seems
to defy the ag ing process.
'Its cells have an extraordinary capacity to
regenerate,' explain David Lloyd, a consultant
liver surgeon at Leicester Royal Infir mary.
He says he can remove ha a liver during
surgery and it will grow to the size of a
complete liver within three months.
If a donor doesn't drink, use drug or suffer
from infection, then it is possible to transplant
a 70-year-old liver into a 20-year-old.

• KIDNEYS
Starts ageing at 50
With kidneys, the number of filtering units
(nephrons) that remove waste from the
bloodstream starts to reduce in middle age.
One effect of this is their inability to turn off
urine production at night, causing frequent
trips to the bathroom.
The kidneys of a 75-year-old person will filter
only half the amount of blood that a 30-year-
old's will.

• PROSTATE
Starts ageing at 50
The prostate often becomes enlarged with age,
leading to problems such as increased need to
urinate, says Professor Roger Kirby, director of
the Prostate Centre in London. This is known
as benign prostatic hyperplasia and affects half
of men over 50, but rarely those under 40.
It occurs when the prostate absorbs large
amounts of the male sex hormone
testosterone, which increases the growth of
cells in the prostate.
A normal prostate is the size of a walnut, but
the condition can increase this to the size of a
tangerine.

• BONES
Start ageing at 35
'Throughout our life, old bone is broken down
by cells called osteoclasts and replaced by
bone-building cells called osteoblasts - a
process called bone turnover,' explains Robert
Moots, professor of rheumatology at Aintree
University Hospital in Liverpool.
Children's bone growth is rapid - the skeleton
takes just two years to renew itself
completely. In adults, this can take ten years.
Until our mid-20s, bone density is still
increasing. But at 35 bone loss begins as part
of the natural ageing process.
This becomes more rapid in post-menopausal
women and can cause the bone-thinning
condition osteoporosis.
The shrinking in size and density of bones can
lead to loss of height. Bones in the back shrivel
up or crumble between the vertebrae. We lose
two inches in height by the time we're 80.

• TEETH
Start ageing at 40
As we age, we produce less saliva, which
washes away bacteria, so teeth and gums are
more vulnerable to decay.
Receding gums - when tissue is lost from
gums around the teeth - is common in adults
over 40.

• MUSCLES
Start ageing at 30
Muscle is constantly being built up and broken
down, a process which is well balanced in
young adults.
However, by the time we're 30, breakdown is
greater than buildup, explains Professor
Robert Moots.
Once adults reach 40, they start to lose
between 0.5 and 2 per cent of their muscle
each year. Regular exercise can help prevent
this.

• HEARING
Starts ageing mid-50s
More than half of people over 60 lose hearing
because of their age, according to the Royal
National Institute for the Deaf.
The condition, known as presbycusis, happens
due to a loss of 'hair cells' - tiny sensory cells
in the inner ear which pick up sound vibrations
and send them to the brain.

• SKIN
Starts ageing mid-20s
The skin starts to age naturally in your
mid-20s.
According to Dr Andrew Wright, a consultant
dermatologist with Bradford NHS Trust, as we
get older production of collagen - the protein
which acts as scaffolding to the skin - slows,
and elastin, the substance that enables skin to
snap back into place, has less spring and can
even break.
Dead skin cells don't shed as quickly and
turnover of new skin cells may decrease
slightly.
This causes fine wrinkles and thin, transparent
skin - even if the first signs may not appear
until our mid-30s (unless accelerated by
smoking or sun damage).

• TASTE AND SMELL
Start ageing at 60
We start out in life with about 10,000 taste
buds scattered on the tongue. This number can
halve later in life.
After we turn 60, taste and smell gradually
decline, partly as a result of the normal ageing
process.
This can be accelerated by problems such as
polyps in the nasal or sinus cavities. It can also
be the cumulative effect of years of smoking.

• FERTILITY
Starts ageing at 35
Female fertility begins to decline after 35, as
the number and quality of eggs in the ovaries
start to fall.
The lining of the womb may become thinner,
making it less likely for a fertilised egg to take,
and also creating an environment hostile to
sperm.
Male fertility also starts to drop around this
age. Men who wait until their 40s before
starting a family have a greater chance of their
partner having a miscarriage, because of the
poorer quality of their sperm.

• HAIR
Starts ageing at 30
Male hair loss usually begins in the 30s. Hair is
made in tiny pouches just under the skin's
surface, known as follices.
A hair normally grows from each follicle for
about three years, is then shed, and a new hair
grows.
However, with male-pattern baldness, changes
in levels of testosterone from their early-30s
affect this cycle, causing the hair follicles to
shrink.
Each new hair is thinner than the previous one.
Eventually, all that remains is a much smaller
hair follicle and a thin stump of hair that does
not grow out to the skin surface.
Most people will have some grey hair by the
age of 35. When we are young, our hair is
coloured by the pigments produced by cells in
the hair follicle known as melanocytes.
As we grow older, melanocytes become less
active, so less pigment is produced, the colour
fades, and grey hairs grow instead