As if going grey was not worrying enough, now comes the unwelcome news that it is linked to heart disease.
Scientists have discovered that hair whitening can indicate an increased risk of damage to arteries supplying the heart with blood.
Some of the biological mechanisms driving coronary artery disease are also responsible for greying hair, they believe.
These include impaired DNA repair, oxidative stress, inflammation, hormonal changes and the halting of cell growth.
The findings could pave the way to identifying patients most at risk of heart disease just by looking at their hair colour.
Dr Irini Samuel, a cardiologist at Cairo University in Egypt, said: “Atherosclerosis (artery disease) and hair greying occur through similar biological pathways and the incidence of both increases with age.
“Our findings suggest that, irrespective of chronological age, hair greying indicates biological age and could be a warning sign of increased cardiovascular risk.”
The team studied 545 adult men who underwent computed tomography (CT) scans for suspected coronary artery disease, which affects the blood vessels bringing oxygen and nutrients to the heart.
Patients were divided into sub-groups according to the state of their arteries and hair colour.
Greying levels were graded using a “hair whitening score” that ranged from one (pure black) to five (pure white).
Each patient’s level of hair greying was determined by two independent observers.
The researchers found that a hair-whitening score of three or more was associated with a statistically significant increased risk of coronary artery disease.
Patients with damaged arteries had higher greying scores than those whose arteries were healthy.
They were also more likely to have calcium deposits in their arteries.
Hair whitening turned out to be an independent predictor of narrowing and hardening of the coronary arteries along with high blood pressure and abnormal blood fat levels.
Dr Samuel added: “Further research is needed, in co-ordination with dermatologists, to learn more about the causative genetic and possible avoidable environmental factors that determine hair whitening.
“A larger study including men and women is required to confirm the association between hair greying and cardiovascular disease in patients without other known cardiovascular risk factors.”