Apples keep bad cholesterol from oxidizing.

An Apple a Day Lowers Level of Blood Chemical Linked to Hardening o...

Eating an apple a day might in fact help keep the cardiologist away, new research suggests.

In a study of healthy, middle-aged adults, consumption of one apple a day for four weeks lowered by 40 percent blood levels of a substance linked to hardening of the arteries.

... the apples lowered blood levels of oxidized LDL -- low-density lipoprotein, the "bad" cholesterol. When LDL cholesterol interacts with free radicals to become oxidized, the cholesterol is more likely to promote inflammation and can cause tissue damage. "When LDL becomes oxidized, it takes on a form that begins atherosclerosis, or hardening of the arteries," said lead researcher Robert DiSilvestro...

"We got a tremendous effect against LDL being oxidized with just one apple a day for four weeks."

The difference was similar to that found between people with normal coronary arteries versus those with coronary artery disease, he said.

DiSilvestro described daily apple consumption as significantly more effective at lowering oxidized LDL than other antioxidants he has studied, including the spice-based compound curcumin, green tea and tomato extract.

"Not all antioxidants are created equal when it comes to this particular effect," he said.