Around 150 B.C., wealthy Romans decided they wanted white bread, made in mechanical dough mixers powered by donkeys, to distinguish themselves from the lower classes who ate bread made from unrefined whole grains.

That obsession with pale loaves of bread has persisted to this day.

Each American eats about 53 pounds of bread a year — and although much of it now comes in packages with "whole grain" on the label, very little is actually 100% whole grain.

And the majority of the hundreds of millions of bagels, tortillas, and croissants that Americans eat are nothing but refined white flour that is stripped of nutrients and fiber, turned into a glucose-boosting, heart-clogging choice.

A new study published in the BMJ shows that eating seven servings a day of refined grains, like those in croissants and white bread, is associated with a 27% greater risk for early death, 33% greater risk for heart disease, and 47% greater risk for stroke.

No wonder heart disease is the leading cause of death for men and women in the U.S.

Unfortunately, it's easy to eat more than seven servings. That equals one big bagel (around five to six servings in a 5- to 6-ounce bagel) at breakfast and two hearty slices of white bread on a sandwich at lunch.

Instead, opt for 100% whole grains. You can cook them up using the wonderful recipes in Dr. Mike's "What to Eat When Cookbook."