There are reasons beyond vanity to feel concerned about the arrival of the first gray hair, with Egyptian cardiologists warning it serves as an indicator of raised coronary artery disease, at least in men.
"Aging is an unavoidable coronary risk factor and is associated with dermatological signs that could signal increased risk," said Dr Irini Samuel of Cairo University in a statement. "More research is needed on cutaneous signs of risk that would enable us to intervene earlier in the cardiovascular disease process."
Samuel wondered if graying hair could be an easy-to-detect signal of internal health, so she had the hair color of 545 men who were in the hospital for CT coronary angiographs assessed on a scale of 1-5. Since the study was done in Egypt, the men had started with dark hair, and 1 indicated pure black hair, while 5 meant their hair was entirely gray or white. Samuel also collected data on more well known indicators of coronary risk, such as diabetes, smoking, family history, and high blood pressure. Then she took the scans.
Since the men with grayer hair were also likely to be older, it's no surprise that their hearts were generally in worse states. However, even after controlling for age and other known factors, scores of 3 or above were associated with higher rates of coronary artery disease and coronary artery calcification.
The mechanism is not entirely clear, Samuel told EuroPrevent 2017, the annual meeting of the European Association of Preventative Cardiology. High blood pressure or cholesterol, while well established predictors of heart disease, don't seem to relate to changes in hair color. Samuel hopes further research on genetic and environmental causes of the timing of graying may help explain the connection.
Nevertheless, the statistical correlation among her sample was sufficiently strong that Samuel recommends men with gray hair take extra care to maintain regular check-ups, healthy diets, and exercise regimes.
"Atherosclerosis and hair graying occur through similar biological pathways and the incidence of both increases with age," Samuel said. "Our findings suggest that, irrespective of chronological age, hair graying indicates biological age and could be a warning sign of increased cardiovascular risk."
She added: "If our findings are confirmed, standardization of the scoring system for evaluation of hair graying could be used as a predictor for coronary artery disease."
So far, no studies have been conducted to see if the relationship also applies to women, another thing Samuel said should be rectified.