Why do I look older than my age?
Because other people read age from a short list of visible cues, and some of them sit further along the list than your real age. Uneven colour and brown spots, lines and wrinkles, lost firmness and volume, and tired-looking eyes are the usual ones. Each has a cause, and some causes can change.
The phrase researchers use is "perceived age": the age a group of observers puts on a face when shown a photograph. It can differ widely from the number on an identity card.
What do people actually read as age?
Colour is one of the best studied cues. In a study of cheek skin from 160 British men, the more evenly melanin and haemoglobin were spread, the younger the face was judged, and evenness of the brown pigment was the stronger cue for age. Earlier work in women, summarised in the same paper, put the contribution of colour distribution at up to twenty years of apparent age. Brown spots and patchy colour are a measurable part of the reading.
Lines come next, and they are measured as well. In the Shanghai study below, the strongest links to perceived age were wrinkles and hyperpigmentation.
Firmness and volume follow. The fat of the face sits in separate compartments, and a review of the anatomy describes age-dependent volume changes in them. Where volume and firmness are the question, the sagging skin page sets out how the layers are assessed.
Then the eyes. When ten people were photographed after normal sleep and after 31 hours without it, observers rated the sleep-deprived faces as having heavier eyelids, redder and more swollen eyes, darker circles, paler skin and more fine lines. That was a small laboratory study of extreme sleep loss, and it shows how much of "looks tired" is read from the eye area.
Why pigment weighs heavily on Asian skin
A 2005 pilot study compared 160 Chinese and 160 French women aged 20 to 60. Wrinkle onset came about 10 years later in the Chinese women, and pigmented spots were a far more important sign of ageing in them: severe in 30% of the Chinese women over 40, against under 8% of the French women. The authors called it a pilot that needs confirming in larger studies, and none of this work was done in Malaysia.
The pattern fits the later Shanghai study. Spots and uneven colour, not only lines, can carry a lot of the reading on Asian skin. They are also several different conditions. Melasma, sun spots and Hori's naevus look alike and are treated differently, and are age spots treatable explains why the diagnosis comes before any laser or cream.
How wide can the gap between real and perceived age be?
In the Shanghai study, 250 Chinese women aged 25 to 70 were photographed and rated. Women of the same chronological age were judged up to 29 years apart. Those judged older scored higher for coarse wrinkles and hyperpigmentation in every age group. Skin colour, hydration and water loss were more weakly linked.
The figure of 29 years is the extreme at the end of one study, and it should be read as a measure of how much perceived age varies, not as a typical gap.
What pushes the reading older?
Sun is the best documented. A study of 186 pairs of identical twins found that more sun exposure, and lack of sunscreen use, went with an older appearance, and that dark patchy discolouration was more common with sun exposure. Because twins share their genes, the comparison is a strong one, though it is a study of association.
Smoking showed the same pattern in the twins: the longer someone had smoked, the older they looked, with more wrinkles and more patchy discolouration.
Sleep is the subject of the small laboratory study above. Short sleep reads as tiredness, and the cues overlap around the eyes. That study does not show whether it adds to the age reading.
Weight is less simple. In the twins, a higher body mass index went with an older look in younger adults (under 40 for a four-point difference, under 55 for an eight-point difference) and a younger look after that. That compares people at different weights, so it says little about people whose weight changed. How rapid weight loss changes the eye area is covered separately in sunken eyes after weight loss.
What can change, and what comes first
The first step is the diagnosis. Which of the cues is doing the work for your face is a clinical question, and it often takes an examination to answer.
Daily sun protection is the one measure with a trial behind it. In an Australian randomised trial of 903 adults, people who used broad-spectrum sunscreen daily showed no detectable increase in skin ageing over 4.5 years, and 24% less than people who used it when they chose. That is one trial in one climate. Sunscreen in the tropics explains what the SPF number leaves out.
Pigment conditions are told apart before they are treated, because melasma, sun spots and other marks do not share one answer, and a treatment that suits one can be wrong for another. Lines and volume come after that, and they too have more than one cause. Why skin looks tired, and why more filler rarely fixes it is a good example of how the reading and the cause can differ.
None of this promises a younger face. It narrows a vague worry to a list a doctor can examine, line by line.
