Ever feel as if you've aged ten years overnight? New research shows this might not be just paranoia.
While it used to be thought ageing was gradual, scientists now believe we have a tipping point when we suddenly lose the battle to hold back the years.
In a study of 100 Japanese women aged between 22 and 55, scientists from beauty brand SK-II discovered that while 'skin power' - the ability to protect itself from UV exposure and pollution, and to renew and regenerate itself - steadily declined, it went into freefall at 35. Mail Online reported.
So what causes this tipping point? 'It comes when the skin's ability to maintain elasticity and good levels of collagen and hydration is outweighed by UV damage, exposure to free radicals and stress,' says Laura J. Goodman, senior scientist at P&G Beauty.
This theory is supported by Harley Street plastic surgeon Rajiv Grover. He recently presented the results of a ten-year study of 100 women, in association with Q-Med, the company behind facial fillers such as Restylane.
Every year he measured brow height, cheek volume, the crease that runs from the nostril to the outside of the lip and jowl thickness.
'While some measurements showed a gradual decline, cheek volume - one of the key factors in a youthful appearance - can drop off suddenly, by as much as 35 per cent in a year,' he says.
However, almost all of the patients who saw an ageing spurt had suddenly lost a lot of weight, suffered a serious illness or undergone a stressful experience, such as divorce, bereavement or redundancy.
His advice to anyone wanting to avoid the tipping point? 'Avoid stress, yo-yo dieting, the sun and smoking. It may not keep you forever young, but it'll stop you looking old before your time.'