We can all probably remember the day we found our first gray hair — some of us as early as high school or college, and some of us in our 30s or 40s. Beyond the beauty and age implications of gray hair, there may be health concerns we should worry about — especially men.

When we first start to get gray, the melanocytes are still present, but they become less active. As less pigment is deposited into the hair, it appears lighter. As graying progresses, the melanocytes die off until there aren't any cells left to produce the color.

Graying hair follows a "50" rule of thumb — that 50 percent of the population has about 50 percent of gray hair by age 50. An early study showed that between 45 and 65 years of age, 74 percent of people were affected by gray hair with a mean intensity of 27 percent. Men had significantly more gray hair than women.

A survey of British men by market research firm Mintel found that 75 percent of men between 45 and 54 years of age worry about their hair turning gray. In fact, men in this age group are more likely to report being worried about going gray than about losing hair (52 percent), being overweight (51 percent), or finding ear and nose hair (50 percent).

But men may have an additional reason to worry about going gray. New data recently presented at the European Society of Cardiology's Europrevent 2017 meeting in Spain entitled "The Degree of Hair Graying in Male Gender as an Independent Risk Factor for Coronary Artery Disease, a Prospective Study" suggests that men who are graying fast should probably see their cardiologists.

According to Dr. Irini Samuel, a cardiologist at Cairo University, Egypt, who conducted the study to examine whether gray hair was an independent risk factor for heart disease, aging is an unavoidable coronary risk factor and is associated with dermatological signs that could signal increased risk. Many of the molecular mechanisms underlying atherosclerosis and graying hair have similar biologic pathways — impaired DNA repair, oxidative stress, inflammation, hormonal changes and senescence of functional cells.

In this study, 545 adult men underwent multislice computed tomography (CT) coronary angiography for suspected coronary artery disease (CAD). Patients were divided into subgroups according to the presence or absence of CAD and the amount of gray/white hair.

A hair whitening score was used to grade the amount of gray hair (1 = pure black hair, 2 = black more than white, 3 = black equals white, 4 = white more than black, and 5 = pure white). Data were also collected on traditional cardiovascular risk factors, including hypertension, diabetes, smoking, dyslipidemia and family history of CAD.

A high hair whitening score (grade 3 or more) was associated with increased risk of CAD independent of chronological age and cardiovascular risk factors, including diabetes, smoking, hypertension and family history. Men with CAD (80 percent) had a statistically significant higher hair whitening score and higher coronary artery calcification than men without CAD. Hypertension, diabetes and dyslipidemia were more prevalent in the CAD group.

These results suggest that, regardless of chronological age, graying hair indicates biological age and may be a warning sign of increased cardiovascular risk.

According to Samuel, further research is needed to learn more about the genetic and possible avoidable environmental factors that determine hair whitening. A larger study that includes both men and women is necessary to confirm the association between hair graying and cardiovascular disease in patients without other known cardiovascular risk factors.