Abstract 004: Independent Effects of 1.5 Ounces/Day Almonds on Lipids, Lipoproteins, and Apolipoproteins in Mildly Hypercholesterolemic Adults
Introduction: Almonds have been studied in the context of blood cholesterol-lowering diets, which consistently show beneficial effects on CVD risk factors. The independent effects of almonds beyond the contributions of a heart healthy diet have not been evaluated.
Hypothesis: A cholesterol-lowering diet with 1.5 oz. /d almonds will elicit greater cardioprotective effects on lipids, lipoproteins, and apolipoproteins than the same cholesterol-lowering diet with an isocaloric muffin substitution.
Methods: A randomized, 2-period, crossover, controlled feeding study was designed to test the effects of 1.5 oz. /d almonds compared to a calorie-matched, high carbohydrate snack. All foods provided were exactly the same in both diets except for the snack (almonds or muffin; 245 kcal/d). Thus, differences in the nutrient profiles of the control diet (59.3% CHO, 15.4% PRO, 25.2% FAT, no almonds/d) and almond diet (51.8% CHO, 16.7% PRO, 31.5% FAT, 1.5 oz. of almonds/d) were due to the nutrient profile provided by each snack. Test diets were matched for PRO (15-17%), saturated fat (~7%) and cholesterol (<200 mg/d). Experimental periods were 6wk, followed by a 2-3wk compliance break. The study sample (n=53) consisted of men and women (BMI 20-35 m/kg2) with moderately elevated LDL-C (128-194 mg/dl for males; 121-190 mg/dl for females).
Results: Both diets decreased total cholesterol (TC), LDL-C, and HDL-C compared to baseline (almond: 21.4 ± 2.8, 18.5 ± 2.1, 3.7 ± 0.8 mg/dl and control: 16.8 ± 2.8, 13.6 ± 2.2, 5.5 ± 0.8 mg/dl, respectively; P <0.001 for all). However, the almond diet decreased LDL-C and TC more than the control diet (P=0.01 and P=0.06, respectively). The almond diet also attenuated the HDL-C response versus the control diet (P=0.003). The almond diet reduced the TC: HDL-C ratio and LDL-C: HDL-C ratio compared to baseline (0.19 ± 0.07; P=0.01 and 0.24 ± 0.05; P <0.001, respectively) and the control diet (0.24 ± 0.06; P <0.001 and 0.20 ± 0.04; P <0.001, respectively). Both diets decreased apolipoprotein B (apoB) and apolipoprotein A1 (apoA1) from baseline (almond: 10.0 ± 1.6 and 5.7 ± 1.6 mg/dl and control: 5.7 ± 1.6 and 8.4 ± 1.7 mg/dl, respectively; P <0.002 for all). The almond diet decreased apoB significantly more and reduced apoA1 significantly less than the control diet (P=0.01 and P=0.04, respectively). The almond diet decreased the apoB: apoA1 ratio versus baseline (0.04 ± 0.01; P <0.001) and the control diet (0.04 ± 0.01; P=0.002).
Conclusion: Using a unique diet design, we showed that 1.5 oz. /d of almonds in a cholesterol-lowering diet has beneficial effects on TC, LDL-C, HDL-C, apoB, and apoA1. By providing a standardized background diet in which all foods were identical except the almond/muffin snack, we demonstrated an independent effect of almonds on CVD risk factors beyond a heart healthy diet which likely is due to the fatty acid profile, dietary fiber, and other bioactives in almonds.
- © 2013 by American Heart Association, Inc.