“Improve your cholesterol!” shout boxes of cereal, frozen food containers, and even breakfast shakes. But does decreasing your cholesterol really make a difference when it’s really particle size and cholesterol level that people should be concerned about when trying to eat a heart healthy diet? Even though cardiovascular disease is largely preventable, about 600,000 people die of heart disease each year, making it the leading cause of death in the United States, since it surpassed pneumonia and the flu in 1921.

New methods are being increasingly used to evaluate risk of heart disease development because of the way “bad cholesterol” threatens our health. Bad cholesterol, known as low-density lipoprotein (LDL), clogs our heart’s arteries, which are used to pump blood to and from the heart, feeding the brain, and increasing heart attack and stroke risk. Good cholesterol, known as high-density lipoprotein (HDL), on the other hand, removes the excess cholesterol and fat from the bloodstream, which keeps us healthy and free from threats.

However, it’s not just the levels doctors are looking at now, because that’s only one side of the story. Instead, researchers have been looking at the size of LDL particles. The bigger they are, the less threat they pose because they don’t circulate and stick to the sides of artery walls as well as small LDL particles can.

“It turns the cholesterol story upside down,” Dr. Ronald Krauss, senior scientist and director of Atherosclerosis Research at Children’s Hospital Oakland Research Institute, told KQED Science.

If your cholesterol is composed of mostly small LDL particles, and you get your cholesterol levels checked, it could be saying you’re within a normal healthy range, while in reality you may still be at risk for heart disease.

 “But it all starts with the particle,” Krauss said. “The LDL particles go into the artery wall and carry the cholesterol with them. So we see the cholesterol in the plaque but it’s the particle concentration and the number of particles that really determine the process.”

It was previously thought that the best approach to fixing this problem is to avoid saturated fats, but that doesn’t affect the LDL particle sizes. However, Krauss provides hope and says sugar and carbohydrates have the power to change LDL particle size and should be avoided. “Taking away eggs and milk has virtually no effect on the bad guys. But you can make a really big improvement if you cut the sugar out,” Krauss said.

A recent study published in the Journal of Lipid Researcher from the University of Pittsburgh is applying the new method of nuclear magnetic resonance spectroscopy to measure lipoprotein particles. They’ve found the size and density of the particles will help doctors provide a more accurate assessment on a patient’s risk for heart disease.

So far, researchers have found women have a lower risk of heart disease of men up until menopause. They aren’t entirely sure as to why, but they believe estrogen has a beneficial effect on arteries. Lower estrogen levels may be able to alter cholesterol abundance or metabolism.

It’s important to point out that boosting estrogen levels isn’t necessarily the key to heart disease prevention, in fact the U.S. Preventive Services Task Force recommends against hormone replacement therapy for the treatment of cardiac risk. Instead, getting cholesterol levels and lipoprotein particle sizes thoroughly checked every five years it a better routine approach, according to Krauss. That goes for both men and women.