Eating an apple a day might help keep the cardiologist away.
The news comes from Ohio State University, where scientists conducted a study in healthy, middle-aged adults.
The participants who ate an apple a day for four weeks lowered their blood levels of oxidized LDL cholesterol by an average of 40 percent.
When people took a daily capsule containing the amount of polyphenol “antioxidants” found in one apple, they showed a similar but smaller benefit.
Oxidation turns healthy cholesterol dangerous
Importantly, the effect exerted by apples was to lower levels of oxidized LDL.
Despite opposing evidence, public health authorities long asserted that people's total and LDL cholesterol levels largely determine their heart risk … but we now know that risk is much better gauged by the totality of your triglycerides and the amounts and relative proportions of various kinds or cholesterol).
However, oxidized LDL cholesterol – which promotes artery clogging/hardening (atherosclerosis) – presents a very real cardiovascular risk.
When LDL cholesterol gets oxidized – often by the poorly controlled proliferation of free radicals promoted by unhealthful diets and lifestyles – it begins to promote inflammation and artery dysfunctions, leading to atherosclerosis.
Fortunately, said lead researcher Robert DiSilvestrom “We got a tremendous effect against LDL being oxidized with just one apple a day for four weeks.” (OSU 2012)
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 curcumin, green tea and tomato extract:
“Not all antioxidants are created equal when it comes to this particular effect,” he said (OSU 2012).
DiSilvestro became interested in studying the health effects of apples after reading a Turkish study that found this habit raised the amount of a specific antioxidant enzyme 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.
Apple a day cut cholesterol oxidation
The OSU researchers recruited 51 non-smoking 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.
They were divided into three groups, each assigned to a different daly regimen for four weeks:
16 ate a large Red or Golden Delicious apple
17 took a capsule with 194mg of polyphenols
18 took a placebo capsule with no polyphenols
The researchers found no effect on oxidized LDLs in the placebo group.
But, as DiSilvestro said, “We got a tremendous effect against LDL being oxidized with just one apple a day for four weeks.” (OSU 2012)
“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. (OSU 2012)
“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.” (OSU 2012)
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.” (OSU 2012)
The study also found eating apples raised those participants' saliva levels of internal antioxidants, which has implications for dental health, DiSilvestro said.
Dr. DiSilvestro discusses his team's findings in this video
The study was funded by a grant from the U.S. Apple Association/Apple Product Research and Education Council and a donation from Futureceuticals Inc. of Momence, Ill.
Ohio State University (OSU). Study: An Apple a Day Lowers Level of Blood Chemical Linked to Hardening of the Arteries. October 2,2012. Accessed at http://researchnews.osu.edu/archive/appleaday.htm
Disilvestro RA, Joseph E, Zhao S, Joshua B. Diverse effects of a low dose supplement of lipidated curcumin in healthy middle aged people. Nutr J. 2012 Sep 26;11(1):79. [Epub ahead of print]
Nemzer BV, Rodriguez LC, Hammond L, Disilvestro R, Hunter JM, Pietrzkowski Z. Acute reduction of serum 8-iso-PGF2-alpha and advanced oxidation protein products in vivo by a polyphenol-rich beverage; a pilot clinical study with phytochemical and in vitro antioxidant characterization. Nutr J. 2011 Jun 15;10:67.