Identical twins reveal major difference to their bodies with just one of them sunbathing and smoking

A study involving multiple sets of identical twins has revealed the effects that smoking and sun exposure can have on our skin.

The clue is in the name: identical. Since they share the same genomes, these types of twins usually look the same, typically with only subtle differences to distinguish one sibling from the other.

Identical twins are difficult to distinguish at a young age (Getty Stock Photo)

Changing hair or accessories are some of the obvious ways twins can differentiate from one another, but studies have shown how other life choices can cause appearances to change over the years.

Published by NBC, one particular study looked at the effects of smoking and sun exposure on the skin and revealed the differences between twins when only one was taking part in the activities.

Among those who took part in the study were twins Barb and Brenda.

Brenda had smoked half a pack of cigarettes a day for at least 14 years, and for 30 years, had approximately 14 hours of sun exposure per week for eight to 10 weeks of the year.

Barb (right) had never smoked in her life (NBC)

In contrast, Barb had never smoked and had just two hours of sun exposure a week - seven times less than her sister.

The differences between the twins were visible, with Barb admitting that she 'love[d] being called the younger one' between her and her sister.

Dr. Bahman Guyuron, a plastic surgeon, pointed to what he described as 'festoons of loose skin' under Brenda's eyes, which he said were attributable to her smoking.

“When I see that [on patients], I don’t have to ask if they smoke. I know they do," he said.

Other impacts of smoking and sun exposure were demonstrated in the study by twins Jeanne and Susan, with Jeanne claiming that her sister looked '10 years older'.

Jeanne (left) said her sister looked 'ten years older' (NBC)

Researchers went slightly further, however, claiming Susan looked 11 and a quarter years older than Jeanne.

Her advanced ageing was attributed to the fact she'd smoked for 16 years of her life, as well as spending as much time as she could in the sun.

Meanwhile, Jeanne was careful to have 'as little exposure as possible'.

Discussing the differences between the twins, Guyuron pointed to Susan’s dark, patchy discoloration and age spots. He also noted how UV light from sun exposure can reduce skin’s elasticity, increase wrinkles and deepen creases.

To protect the skin from the impacts of the sun, Johns Hopkins Medicine recommends limiting sun exposure and protecting your skin by using sunscreen or wearing clothes to cover your skin.