Plant-derived bioactives and long-chain omega-3 fatty acids as nutritional interventions for cardiovascular disease risk factors
Open Access
- Author:
- Richter, Chesney Kirstin
- Graduate Program:
- Nutritional Sciences
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- April 18, 2016
- Committee Members:
- Penny Margaret Kris Etherton, Dissertation Advisor/Co-Advisor
Penny Margaret Kris Etherton, Committee Chair/Co-Chair
Gordon Lee Jensen, Committee Member
Sheila Grace West, Committee Member
Eric Loken, Committee Member - Keywords:
- inflammation
fish oil
endotoxemia
strawberries
oxidative stress
arterial stiffness
postprandial dysmetabolism - Abstract:
- Nutritional interventions can be used to modify multiple risk factors for cardiovascular disease (CVD). This dissertation research investigated the effects of plant-derived bioactives and long-chain omega-3 fatty acids on CVD risk factors. The first study evaluated whether incorporating 40 g of freeze dried strawberry powder into a high-fat meal altered postprandial vascular function or attenuated triglyceride, glucose, and insulin responses. Overweight but otherwise healthy adults (n = 30) consumed a control and strawberry meal in a randomized crossover design. Both meals significant decreased the augmentation index (p < 0.002) and significant increased serum triglycerides, insulin, and glucose compared to baseline (p < 0.001), but with no significant differences between meals. Longer-term strawberry supplementation may be needed to improve CVD risk factors. The second study was a placebo-controlled, double-blind, randomized, crossover trial (8 wk treatment, 8 wk washout) investigating the effects of a pharmaceutical dose (3.4 g/d) of EPA+DHA on inflammatory responses to low-dose endotoxemia (intravenous 0.6 ng/kg purified lipopolysaccharide) in 20 healthy young men. Endotoxin administration produced a robust inflammatory response with consistent elevations in C-reactive protein, interleukin-6, and tumor necrosis factor-α; however, there was no difference in the peak concentration of any inflammatory markers following EPA+DHA supplementation compared to the olive oil control (p > 0.05). Omega-3 fatty acids may exert beneficial effects on inflammation via mechanisms other than cytokine production. The third study analyzed the effect of EPA+DHA supplementation on urinary isoprostane production following low-dose endotoxemia in two study populations: 1) described above and 2) healthy young adults (n = 17 [10M]) supplemented with 0, 300, 600, 900, or 1800 mg/d EPA+DHA for 5 months. In both studies, EPA+DHA increased F3-isoprostanes. In the study of healthy adults, EPA+DHA supplementation (600-1800 mg/d) attenuated total urinary isoprostane production in a model that also included body mass index. More research is needed to clarify whether omega-3s can attenuate acute oxidative stress. Although neither the strawberry nor the omega-3 intervention demonstrated a significant effect on the specified CVD risk factors, these null findings improve our understanding of these interventions and will aid in the development of future clinical studies of dietary bioactives.