What does gray hair mean for our heart health?

For about 91 percent of us, about half of our hair will be gray by the age of 65. Could the color be a sign of our heart's health? New research shows a link between the hair color and your heart risk.

"Some really well-respected researchers report on over 500 men, were they mainly dark, salt-and-pepper, more white or totally white. They did the most sophisticated heart test you can do - a CAT scan on the heart with iodine dye - and they found a strong relationship, that, even after they factored in smoking, blood pressure and cholesterol, the grayer your ragtop is the grayer your arteries," says America's Holistic Heart Doc Dr. Joel Kahn.

Doctors warn this might just be a subtle clue but an important one because so often we find out about heart disease in the emergency room.

The theory is that what causes your hair to gray is also damaging your heart.

"Oxidative stress, which is aging, the rusting of the body. Well, that occurs on arteries but we can't see it. That's actually the main cause of hair turning gray, is oxidative stress," explains Dr. Kahn.

So if you're taking a closer look at your hair, take a glance at your earlobe to see if you have a specific crease, as seen in the video player above.

"If you have a deep diagonal earlobe crease, you have an increased risk of having silent heart blockage," says Dr. Kahn. "It's called Frank's sign. We were taught it in medical school. Everyone forgot it but about two years ago using CT technology of the heart, it actually is pretty valid."

The diagonal crease is easy to look for and, again, might just be another clue.

You can see other hidden clues that you might have heart disease on Dr. Kahn's website here.