Balding men and those who turn grey prematurely are five times more likely to develop heart disease before the age of 40, according to new research.

Going bald or grey prematurely is a bigger risk factor in heart disease than obesity.

"The incidence of coronary artery disease in young men is increasing but cannot be explained by traditional risk factors," said lead researcher Sachin Patil, of the UN Mehta Institute of Cardiology and Research Centre at Ahmedabad, India

Premature greying and male-pattern baldness correlate well with vascular age – the biological age of our arteries – regardless of our actual chronological age, Patil said. If your vascular age is greater than your chronological age, you may be more at risk of developing heart disease.

Cardiovascular diseases are the world's biggest killers, causing the deaths of around 17.7 million people every year.

The study examined 790 men under the age of 40 who had heart disease and compared them to 1,270 similarly aged men who had no signs of the disease.

The researchers found that the young men with heart disease were at least five times more likely to be prematurely grey or balding than the healthy participants.

"Baldness and premature greying should be considered risk factors for coronary artery disease," said co-author Kamal Sharma, also from the Mehta Institute.

"These factors may indicate biological, rather than chronological, age which may be important in determining total cardiovascular risk. Currently, physicians use common sense to estimate biological age but a validated scale is needed."

The findings were presented at the 69th annual conference of the Cardiological Society of India in Kolkata.

It is important to note that the study does not suggest a causal link between going bald or grey early and developing heart disease.

However, Alun Hughes, professor of cardiovascular physiology and pharmacology at University College London suggested that there may be some form of biological link.

"Since grey hair is due to impaired renewal of melanocyte stem cells, people have speculated that it may be an indicator of DNA damage associated with ageing," he said.

Traditional risk factors

In addition, since hair follicles are influenced by androgens – hormones that regulate the development of male characteristics, such as testosterone – it has been suggested that early male pattern baldness could reflect differences in responses to androgens that may influence the risk of heart disease, Hughes added.

Marco Roffi, head of the Interventional Cardiology Unit at Geneva University Hospital, stressed that despite the new findings, traditional risk factors – many of which can be influenced by a person's lifestyle choices - are still responsible for most cases of heart disease.

"Classical risk factors such as diabetes, family history of coronary disease, smoking, sedentary lifestyle, high cholesterol levels and high blood pressure are responsible for the vast majority of cardiovascular disease," he said.

"It remains to be determined whether potential new risk factors, like the ones described, may improve cardiovascular risk assessment."