Reference
Chai SC, Hooshmand S, Saadat RL, Payton ME, Brummel-Smith K, Arjmandi BH. Daily apple versus dried plum: impact on cardiovascular disease risk factors in postmenopausal women. J Acad Nutr Diet. 2012;112(8):1158-1168.
Design
Participants were randomly assigned to eat a portion of dried fruit each day for 12 months. Fasting blood samples were collected at baseline, and at 3, 6, and 12 months to measure various biomarkers.
Participants
One-hundred sixty postmenopausal women were recruited from 2007 through 2009. They were not receiving hormone therapy or other agents, including cholesterol-lowering drugs, for at least 3 months prior to the start of the study. They were free from bone disease, renal disease, urolithiasis, cancer, cardiovascular disease, diabetes mellitus, respiratory disease, and liver disease. Heavy smokers were excluded. Approximately 82% of the participants in each group completed the study.
Study Medication and Dosage
Participants were randomly assigned to eat a prescribed portion of dried fruit each day for 12 months. Half of the participants ate 75 g of dried apples, and the other group ate 100 g of dried plums. Though these portions differed in weight, they were comparable in carbohydrate, fat, fiber, and total caloric content. The participants were obviously not blinded to which fruit they were assigned, but the statisticians who analyzed the data were.
Outcome Measures
Blood serum was analyzed for total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides (TG), lipid oxidation, and c-reactive protein. Dieticians collected a 7-day dietary recall from the each participant at baseline and at 3, 6, and 12 months.
Key Findings
Those women consuming dried apples lost an average of 1.5 kg body weight by the end of the study. Total cholesterol and LDL-cholesterol in the apple group decreased significantly from baseline by 9% and 16%, respectively, after 3 months (P=0.0022). After 6 months, the serum values had decreased to 13% and 24%, respectively and remained constant through the rest of the trial.
In the dried-plum group, compared to baseline levels, there was a non-significant decrease in total and LDL cholesterol of 3.5% and 8%, respectively, at the 12-month time point (P=0.8388). Otherwise, the dried plums did not affect the lipid profile.
This study, and no doubt future studies, will help us tailor the dietary recommendation to eat more fruit in order to address the particular health concerns of our patients.
While HDL cholesterol did not change significantly in the apple group, measurements did increase numerically by 3%. Triglyceride levels dropped non-significantly by 9%. Cardiovascular risk ratios dropped significantly, total cholesterol:HDL cholesterol by 15% and LDL:HDL by 21%. C-reactive protein dropped significantly by 17% in the dried plum group within 3 months and then remained constant. The dried-apple group showed a slower response in C-reactive protein levels; a significant decrease was not seen until 6 months, at which time it had dropped by 22% from baseline. At 12 months, C-reactive protein had decreased 32% in the apple group. Both dried apples and plums decreased lipid oxidation status significantly; at 12 months, levels had dropped by 33% and 38%, respectively.
Practice Implications
Astute readers will recognize something familiar about this study. In an earlier incarnation and analysis of data from this cohort, dried prune consumption was shown to have a positive impact on biomarkers of bone density. In that study, apples were used as the control fruit, and they had no effect on bone markers.1
Almost the opposite is true in this study. Dried plums had no significant impact on markers associated with cardiovascular disease, with the notable exception that they were associated with a 38% drop in C-reactive protein at 12 months. Dried apples had a significant impact on total cholesterol, LDL cholesterol, lipid oxidation, and C-reactive protein. All of these markers moved in a direction associated with decreased cardiovascular disease risk.
Is this a practical intervention? Almost: While more than three-fourths of the study participants completed the study, eating 75 g of dried apples per day may pose a challenge to many patients. The benefits seen from eating dried apples are similar to those seen from nuts in other studies, and it may be that in combination, nuts and dried apples have an additive effect so that smaller portions of each may be required to achieve the same benefit. Whether an equivalent amount of fresh apples (~1 lb) or applesauce (2½ cups) would have the same impact on cardiovascular disease risk is not clear.
What these results do tell us is that all fruits are not the same. This study, and no doubt future studies, will help us tailor the dietary recommendation to “eat more fruit” in order to address the particular health concerns of our patients.
