An apple a day lowers level of blood chemical linked to hardening of the arteries

(Medical Xpress)—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.

Taking capsules containing polyphenols, a type of antioxidant found in apples, had a similar, but not as large, effect.

The study, funded by an apple industry group, found that the apples lowered of oxidized LDL—low-density lipoprotein, the "bad" cholesterol. When LDL cholesterol interacts with to become oxidized, the cholesterol is more likely to promote inflammation and can cause .

"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."

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

The study is published online in the Journal of and will appear in a future print edition.

This video is not supported by your browser at this time.

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, and tomato extract.

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

DiSilvestro first became interested in studying the of eating an apple a day after reading a Turkish study that found such a regimen increased the amount of a specific in the body.

In the end, his team didn't find the same effect on the enzyme, but was surprised at the considerable influence the apples had on oxidized LDL.

For the study, 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-area grocery store daily for four weeks; 17 took capsules containing 194 milligrams of polyphenols a day for four weeks; and 18 took a placebo containing no polyphenols. The researchers found no effect on oxidized LDLs in those taking the placebo.

"We think the polyphenols account for a lot of the effect from apples, but we did try to isolate just the polyphenols, using about what you'd get from an apple a day," DiSilvestro said. "We found the polyphenol extract did register a measurable effect, but not as strong as the straight apple. That could either be because there are other things in the apple that could contribute to the effect, or, in some cases, these bioactive compounds seem to get absorbed better when they're consumed in foods."

Still, DiSilvestro said polyphenol extracts could be useful in some situations, "perhaps in higher doses than we used in the study, or for people who just never eat apples."

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.

The study was conducted as a Master's thesis by graduate student Shi Zhao, and was funded by a grant from the U.S. Apple Association/ Product Research and Education Council and a donation from Futureceuticals Inc. of Momence, Ill.

Also involved in the study were associate professor Joshua Bomser and research associate Elizabeth Joseph, both in the Department of , which is housed in the university's College of Education and Human Ecology.

Related Stories

'Apple a day' advice rooted in science

Apr 12, 2011

Everyone has heard the old adage, "an apple a day keeps the doctor away." We all know we should eat more fruit. But why apples? Do they contain specific benefits?

Polishing the apple's popular image as a healthy food

Mar 02, 2011

Scientists are reporting the first evidence that consumption of a healthful antioxidant substance in apples extends the average lifespan of test animals, and does so by 10 percent. The new results, obtained with fruit flies ...

Recommended for you

Tooth loss linked to slowing mind and body

1 hour ago

The memory and walking speeds of adults who have lost all of their teeth decline more rapidly than in those who still have some of their own teeth, finds new UCL research.

Hot flashes linked to increased risk of hip fracture

5 hours ago

Women who experience moderate to severe hot flashes and night sweats during menopause tend to have lower bone mineral density and higher rates of hip fracture than peers who do not have menopausal symptoms, according to a ...

Core hospital care team members may surprise you

5 hours ago

Doctors and nurses are traditionally thought to be the primary caretakers of patients in a typical hospital setting. But according to a study at the burn center intensive care unit at Loyola University Health System, three ...

User comments

Adjust slider to filter visible comments by rank

Display comments: newest first

daqman
3.7 / 5 (3) Oct 02, 2012
Sorry you lost me at:

"The study, funded by an apple industry group,"

I could hardly be less surprised if they also reported that apples cure cancer and help you walk on water.
Meyer
3.5 / 5 (2) Oct 02, 2012
Sorry you lost me at:

"The study, funded by an apple industry group,"

I made it all the way to "16 participants". :)
ziphead
not rated yet Oct 07, 2012
Sorry you lost me at:

"The study, funded by an apple industry group,"

I could hardly be less surprised if they also reported that apples cure cancer and help you walk on water.


Yeah.... 'cause this is sooo much worse than GSK, Pfizer et al. funding studies to evaluate their own meds and only publishing those whose findings they like.

Pot, kettle much?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.