Now, the outcomes of two controlled clinical trials suggest that adding the familiar fruit to your diet exerts beneficial cardiovascular effects … without adding pounds
Both papers were presented last April at the Experimental Biology 2011 scientific meeting in Washington, DC.
Study #1 – Dried apples lowered LDL cholesterol and inflammation
Experimental studies show that the pectin fiber and polyphenols (antioxidants) in apples improve animals' blood cholesterol profiles and lower their levels of pro-inflammatory molecules.
Now, a clinical trial led by Dr. Bahram H. Arjmandi, PhD, RD, of Florida State University suggests that apples are a “super food” … at least with regard to heart health.
Arjmandi's research is the first to evaluate the long-term, cardio-protective effects of daily apple consumption in postmenopausal women (Chai SC et al. 2011).
The Florida team randomly assigned 160 women aged 45 to 65 to one of two groups:
The test group ate 75g (2.6 oz) of dried apples daily for a full year. The control group ate dried prunes every day for a year.
Blood samples were taken at the outset and again at three, six and 12 months.
The results surprised Dr. Arjmandi, who characterized them as, “incredible changes in the apple-eating women happened by 6 months – they experienced a 23% decrease in LDL cholesterol.” (EB 2011)
In addition, blood levels of HDL cholesterol or “good” cholesterol rose by about four percent.
LDL is known, rather misleadingly, as “bad cholesterol.”
While such a large drop in LDL levels could be beneficial for many people, it's really the oxidation of LDL and other forms of cholesterol by free radicals that leads to arterial plaque and cardiovascular disease.
So it's perhaps as or more significant that the apple group developed lower blood levels of “lipid hydroperoxide” (oxidized cholesterol) and C-reactive protein, which is a key marker for inflammation in the blood and a sign of higher heart risk.
Surprisingly, the extra 240 calories per day consumed from the dried apple did not lead to weight gain in the women … in fact, they lost an average of 3.3 lbs.
The weight loss could be the fruit's pectin, which is known to have a satiating effect, and the pyruvate abundant in apples, which alters metabolism in positive directions.
Study #2 – Apples, apple products, and apple polyphenols cut cholesterol oxidation
In the second, separate study, researchers from Ohio State University recruited 64 healthy, middle-aged volunteers, who were divided into four groups of 16 each (Zhao S, DiSilvestro RA 2011).
For one month, members of each of the groups were assigned one of four diet regimens, in addition to their regular meals:
One fresh apple per day
Multiple apple products: one apple, one cup apple juice, one serving apple sauce per day
Apple-extract capsules providing the polyphenol content of three apples
Blood tests showed that levels of oxidized LDL fell in all three apple groups (fresh, multi-products, extract), but not in the placebo group.
The exact reason for the drop in oxidized LDL is unclear. Unlike some prior apple studies, there were no increases in levels of the antioxidant enzyme superoxide dismutase 1 in the volunteers' red blood cells.
As the authors wrote, “… apple product consumption can decrease plasma contents [blood levels] of oxidized LDL, which could present a reasonable strategy for nutritional prevention of atherosclerosis.” (Zhao S, DiSilvestro RA 2011)
What's the take-home message?
Eve's disobedience may have cost humankind lives of ease in Eden ... but at least it had a silver lining.
Chai SC et al. Daily apple consumption promotes cardiovascular health in postmenopausal women FASEB J March 17, 2011 25:971.10. Accessed at http://www.fasebj.org/cgi/content/meeting_abstract/25/1_MeetingAbstracts/971.10?sid=865cadd3-0785-4c33-a228-5e99730bd54a
Experimental Biology 2011 (EB). ‘Apple a Day' Advice Rooted in Science. Accessed at http://experimentalbiology.org/eb2011archive/content/upload/file/EB_Media/2011/ASN%20Apple%20a%20Day.pdf
Zhao S, DiSilvestro RA. Effects of Apple Products on Plasma LDL Oxidation FASEB J March 17, 2011 25:981.11. Accessed at http://www.fasebj.org/cgi/content/meeting_abstract/25/1_MeetingAbstracts/981.11?sid=865cadd3-0785-4c33-a228-5e99730bd54a