An apple a day may lower LDL cholesterol

October 3, 2012

A study published in the Journal of Functional Foods shows that eating an apple a day may lower cholesterol.

The researchers recruited nonsmoking healthy adults between the ages of 40 and 60 who had a history of eating apples less than twice a month and who didn’t take supplements containing polyphenols or other plant-based concentrates. In all, 16 participants ate a large Red or Golden Delicious apple purchased at a Columbus, Ohio-area grocery store daily for four weeks; 17 took capsules containing 194 mg of polyphenols a day for four weeks; and 18 took a placebo containing no polyphenols.

The researchers found that those that consumed the apple a day had a 40% lower level in the blood of a substance linked to hardening of the arteries. The apples lowered blood levels of oxidized LD— 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. Taking capsules containing polyphenols, a type of antioxidant found in apples, had a similar, but not as large, effect. The researchers found no effect on oxidized LDLs in those taking the placebo.

“When LDL becomes oxidized, it takes on a form that begins atherosclerosis, or hardening of the arteries,” said lead researcher Robert DiSilvestro, Professor of Human Nutrition at Ohio State University and a researcher at the university’s Ohio Agricultural Research and Development Center. “We got a tremendous effect against LDL being oxidized with just one apple a day for four weeks.”

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.

The study also found eating apples had some effects on antioxidants in saliva, which has implications for dental health, DiSilvestro said. He hopes to follow up on that finding in a future study.