Going grey early means you are at an increased risk of suffering a heart attack, a new study shows.

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."