EFFECTS OF POLYPHENOLIC-RICH DARK CHOCOLATE AND ALMONDS ON CARDIOVASCULAR RISK FACTORS IN OVERWEIGHT AND OBESE ADULTS
Open Access
- Author:
- Lee, Yujin
- Graduate Program:
- Nutritional Sciences
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- October 06, 2016
- Committee Members:
- Penny M. Kris-Etherton, Dissertation Advisor/Co-Advisor
Penny M. Kris-Etherton, Committee Chair/Co-Chair
Xiang Gao, Committee Member
Gregory C. Shearer, Committee Member
Sheila G. West, Outside Member - Keywords:
- Dark chocolate
Cocoa
Almonds
Lipids
Lipoproteins
Flow-mediated dilation
Coronary heart disease - Abstract:
- Cardiovascular disease (CVD) is the leading cause of death in the United States [1]. Prospective studies have shown that dark chocolate/cocoa intake is associated with a decreased risk of CVD events [2, 3]. Consistent results were observed in the previous randomized controlled trials in which the consumption of dark chocolate/cocoa improved endothelial function and blood pressure [4, 5]. Almonds are a rich source of monounsaturated fatty acids, plant protein, and minerals. Previous intervention studies have demonstrated that almond consumption has lipid lowering effects [6, 7]. However, the combined consumption of dark chocolate/cocoa and almonds has not been investigated in a controlled-feeding setting. We hypothesized that the individual and combined consumption of dark chocolate/cocoa and almonds would favorably affect CVD risk factors; the effects will be greatest when both dark chocolate/cocoa and almonds were consumed compared with a control diet. A randomized, 4-period, crossover, controlled-feeding trial was conducted in 31 overweight and obese participants with elevated low-density lipoprotein cholesterol (LDL-C). Each treatment period was 4 weeks long, followed by a 2 week compliance break. Participants consumed each of 4 isocaloric, weight maintenance diets with 1) no treatment foods (Average American Diet, AAD), 2) 42.5 g of almonds/day (ALD), 3) 18 g of cocoa and 43 g of dark chocolate/day (CHOC), or 4) both foods (CHOC+ALD) for 4 weeks. The concentrations of total cholesterol (TC), non-high-density lipoprotein cholesterol (non-HDL-C) and LDL-C were lower after the ALD compared with the AAD (P < 0.05). The CHOC+ALD decreased apolipoprotein B (ApoB) compared with the AAD (P < 0.05); however, the CHOC did not affect any of lipids and lipoproteins. For LDL subclasses, the ALD decreased large, buoyant LDL particles by -5.7 % (LDL1+2) whereas the CHOC+ALD decreased small, dense LDL particles (LDL3+4) by -12.0 % (P < 0.05). There were no treatment effects on blood pressure, endothelial function and markers of oxidative stress. Percentage reductions in Framingham 10-year coronary heart disease (CHD) risk score from baseline were significant after the ALD (-16.98 ± 4.37%, P < 0.01) and CHOC+ALD (-10.77 ± 4.37%, P < 0.05). None of the treatment diets influenced C-reactive protein (CRP). Participants were divided into low and high inflammatory groups, using median CRP value at baseline (1.2 mg/L). There were significant interaction effects between treatment and baseline CRP status for ApoB (P = 0.04), diastolic blood pressure (P < 0.01), and LDL oxidation (P = 0.03). The level of ApoB was significantly decreased from baseline after the AAD, ALD, and CHOC+ALD in individuals in the low inflammatory group; however, there were no changes in ApoB in those in the high inflammatory group. The reductions in diastolic blood pressure were observed after the AAD (P = 0.01), ALD (P < 0.001), and CHOC (P < 0.001) in those with a low CRP, but not in those with a high CRP (P > 0.05). Furthermore, the lag time of LDL oxidation tended to increase after the CHOC+ALD (P = 0.08) in individuals in the low CRP group whereas there were no changes in the LDL oxidation in those in the high CRP group. Our study demonstrates that consumption of almonds alone or combined with dark chocolate improves lipid, lipoprotein, and apolipoprotein profiles, which results in decreasing Framingham 10-year CHD risk scores. Furthermore, CRP modulated diet-induced metabolic changes. Baseline inflammatory status should be taken into account in future diet intervention studies.