Chicago ? Even small amounts of dark chocolate might help to prevent the sort of blood clots that cause heart attacks and strokes, a finding that researchers say could make the treat a routine part of a heart-healthy diet.

The benefits of a class of chemicals called flavonols, derived from cacao beans, have been emerging from research for decades. But previous studies have been laboratory investigations involving large doses of flavonols – equivalent to eating several pounds of chocolate a day.

Diane Becker, lead author of a study presented Tuesday, said it is the first one to find a significant effect in people who ate chocolate in amounts that chocolate lovers more typically consume.

“Some dark chocolate looks like it’s healthy in small quantities,” said Becker, who presented her findings at a scientific meeting of the American Heart Assn. in Chicago. “Halloween basket chocolate and vending machine chocolate are definitely not on this agenda.”

Becker is a professor of health policy and management at the Johns Hopkins School of Medicine and the Hopkins Bloomberg School of Public Health. She is also a vegetarian and a self-described “chocoholic.”

Becker’s discovery came about because chocoholics just couldn’t stay away from their addiction.

Her study of 1,535 people was intended to look at how aspirin affected blood platelets.

Subjects were specifically instructed to stay away from chocolate, tea, strawberries and red wine.

But 139 people confessed to snacking on chocolate-chip cookies and other products. One subject admitted eating a gallon of chocolate ice cream.

Becker analyzed the cheaters’ urine and found less thromboxane, a compound that indicates blood clotting. Blood analysis also showed slower clotting.

A person would have to eat at least a couple of tablespoons of dark chocolate a day to see some benefit – and it’s still not as effective as a single baby aspirin, which is usually prescribed to heart patients.

Matching aspirin would require eating several bars of chocolate a day, which could lead to other problems, such as obesity and diabetes – to say nothing of tooth decay.