April 12, 2011 -- Eating an apple or two each day may reduce heart disease risk factors, a new study shows.
The study, which is the latest to polish the apple’s heart-healthy reputation, found that eating apples daily appeared to lower levels of cholesterol and two other markers associated with plaques and inflammation in artery walls.
“We were pleasantly surprised ...” that apples so effectively lowered LDL (bad) cholesterol, says study researcher Bahram H. Arjmandi, PhD, RD, Margaret A. Sitton Professor and Chair, Department of Nutrition, Food and Exercise Sciences at The Florida State University in Tallahassee.
The study was presented at Experimental Biology 2011, in Washington, D.C.
Experts said the study’s results were consistent with previous evidence that apples do indeed live up to the famous adage about keeping the doctor away.
“When we look at the whole composite of human studies and animal studies and in vitro lab studies, when you look at the active components in apples and apple juice, there’s definitely benefit,” says Dianne A. Hyson, PhD, RD, a nutritionist and researcher at the University of California at Davis.
Hyson, who was not involved in the current research, recently completed a review of 80 studies, published since 2005, on the health benefits of apples, and she says that in addition to their cardiovascular benefits, there’s some evidence that apples help regulate blood sugar and control appetite, protect against cancer, and safeguard the lungs.
Pitting Apples Against Prunes
For the study, researchers recruited 160 women and randomly assigned them to eat daily servings of either dried apples or prunes, which are dried plums.
After a year, the women in the apple group saw their total cholesterol drop by an average of 14%. Their LDL cholesterol was reduced by an average of 23%. Levels of lipid hydroperoxide, a biochemical involved in the formation of heart-clogging plaques, and C-reactive protein, which is a marker of inflammation, were both down by about one-third.
And the women in the apple group lost weight -- an average of about 3 pounds over the course of a year.
Arjmandi says the women in the prune group also saw some slight reductions in those heart markers, but not to the same extent as those who ate apples.
Experts say there are several possible explanations for how apples aid the heart.
Apples are rich in pectin, a soluble fiber, which blocks cholesterol absorption in the gut and encourages the body to use, rather than store, the waxy stuff.
Apple peels are also packed with polyphenols -- antioxidants that prevent cellular damage from free radicals.
Though the study used dried apples for convenience, Arjmandi says fresh are likely to be even better. And it doesn’t matter if they’re green, red, or golden. “Any varieties of apples are good,” he says.
Another key, Dyson says, is eating the whole fruit, rather than looking for individual components in supplements.
“Most of the time, in many studies, the whole is better than the sum of its parts,” she says.
As far as how much to eat, just follow the apple-a-day adage, though Arjmandi says, two-a-day might be even better.
“That’s doable and practical and people like apples,” he says.
This study was presented at a medical conference. The findings should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.