Dianne Hyson

Strawberry Modulates LDL Oxidation and Postprandial Lipemia in Response to High-Fat Meal in Overweight Hyperlipidemic Men and Women

Background: Elevated levels of lipids, such as total cholesterol (TC), low-density lipoprotein cholesterol (LDL), and triglycerides (TG), are widely recognized as risk factors for cardiovascular disease (CVD). Oxidized LDL (OxLDL) is an emerging risk factor considered relevant in oxidative stress and endothelial dysfunction, which is implicated in the progression of CVD. Consumption of a diet rich in polyphenols may be cardioprotective through its impact on oxidative stress and protecting LDL from oxidation. Objectives: This study was designed to test the ability of strawberry phenolic compounds to mitigate the postprandial effects of a high-fat meal on OxLDL as well as investigate the effects of phenolic compounds on lipid metabolism. Methods: Twenty-four hyperlipidemic men and women (14 women, 10 men; mean age 50.9 ± SD 15 years) were recruited to participate in this randomized, single-blind, placebo-controlled, 12-wk crossover trial. After a 10-day run-in period, subjects consumed either an active strawberry beverage (Str; containing 10 g freeze-dried fruit) or a placebo (Pbo) beverage matched in energy and macronutrient composition for 6 weeks. Twice before randomization and once at the 6-week crossover point, subjects received either Str or Pbo with a high-fat challenge meal (HFM). TC, LDL, high-density lipoprotein cholesterol, TG, and OxLDL were measured at defined intervals for 6 h before and after HFM challenge. Fasting concentrations of blood variables at 0, 6, and 12 weeks were compared to assess chronic intake of Str or Pbo. Results: After the HFM during the run-in period, TG and OxLDL were lower after Str than Pbo (p  =  0.005, p  =  0.01, and p  =  0.0008, respectively). HFM responses after 6 weeks of Str versus Pbo resulted in decreased lipid levels and a sex by treatment interaction for OxLDL (p  = < 0.0001, and p  =  0.0002). Conclusion: The present results support a role for strawberry in mitigating fed-state oxidative stressors that may contribute to atherogenesis.

Postprandial Lipemia is Associated With Platelet and Monocyte Activation and Increased Monocyte Cytokine Expression in Normolipemic Men

The activation of platelets and monocytes has been implicated in the development of cardiovascular diseases. We asked the question if postprandial lipemia following a fatcontaining meal is associated with platelet and monocyte activation and increased platelet-monocyte interaction. Thirteen healthy, normal weight, normolipemic males, 20 to 49 years, consumed a 40% fat meal of whole foods. Blood samples were obtained at fasting and 3½ and 6 hours after ingestion. Triglyceride levels increased to 48% over baseline at 3½ hours postconsumption and returned to fasting levels by 6 hours. Multiparameter flow cytometry using monoclonal antibodies showed that the percentage of platelets expressing surface P-selectin and the activated conformation the GPIIb-IIIa receptor was significantly higher at 3½ hours compared to fasting. The percentage of platelet-monocyte aggregates increased by 36% at 3½ hours and 43% at 6 hours postconsumption. The percentage of monocytes expressing intracellular tumor necrosis factor-tx (TNF-ax) increased seven and eightfold at 3½ and 6 hours, respectively. The expression of interleukin-l,B (IL-1p increased in a similar manner. These data suggest activation of platelets and monocytes after a moderate fat meal. Repetitive activation of platelets and monocytes could be an early event in the initiation and development of atherosclerosis.

Lifestyle modification program in management of patients with coronary artery disease : the clinical experience in a tertiary care hospital.

OBJECTIVES The authors examined clinical outcomes in 71 male and female patients with coronary atherosclerosis who enrolled in a 2-year, independent-living, lifestyle modification program. The findings in 43 patients who completed the program were compared with those in 28 patients who dropped out of the program. BACKGROUND Clinical studies suggest that lifestyle modification of risk factors for coronary atherosclerosis reduces subsequent cardiac events but there are very few reports of the effect of these programs in patients living independently. METHODS Patients with diagnosed coronary atherosclerosis were managed for a 2-year period in a structured multidisciplinary program by a team that included two cardiologists, a nurse, a dietitian, an exercise physiologist, and a clinical psychologist. The overall aim of the program was to normalize or control all major reversible cardiovascular risk factors. Patients were required to participate in several weekly sessions for exercise, meditation/stress reduction training, dietary education and counseling, and participatory dinners. There was a strong emphasis on patients self care, inclusion of support members, and regular monitoring of and feedback to patients. RESULTS Data comparing baseline and 2-year outcomes showed a significant reduction in body weight, dietary intake of total/saturated fat and cholesterol, serum low- and high-density lipoprotein concentration, and an increase in exercise capacity. In the compliant group, the incidence of cardiac events was 2.3% over 2 years. CONCLUSION Multidisciplinary lifestyle modification programs addressing cardiovascular risk factors are known to have a significant impact upon cardiac risk factors in patients with coronary atherosclerosis. Data show that these changes can be accomplished in independent-living patients in a program offered through a routine cardiology service. However, compliance is an important issue in these self-regulated programs.

Apple juice consumption reduces plasma low-density lipoprotein oxidation in healthy men and women.

ABSTRACT Epidemiological studies show that consumption of fruits and vegetables is associated with beneficial effects on human health including reduced risk of coronary artery disease (CAD). Fruits and their juices contain phytochemicals that inhibit in vitro low-density lipoprotein (LDL) oxidation and may account, in part, for their protective effect. However, reports of in vivo antioxidant effects from fruit intake are limited. We conducted a human trial to examine the in vivo effect of consumption of apples (both whole and juice) in an unblinded, randomized, crossover design. Healthy men and women added 375 ml of unsupplemented apple juice or 340 g of cored whole apple to their daily diet for 6 weeks, then crossed over to the alternate product for 6 weeks. Blood samples were obtained at baseline and after each dietary period. Compliance was monitored via biweekly 5-day food records, bodyweight checks, and meetings with study personnel. There were no significant differences between groups in intake of dietary fat, cholesterol, total carbohydrate, sugar, or calories throughout the study. Dietary fiber intake increased by 22% with whole apple consumption. Body weight, fasting serum lipid concentration, and other lipoprotein parameters were unchanged. Apple juice consumption increased ex vivo copper (Cu(++))-mediated LDL oxidation lag time by 20% compared with baseline. Apples and apple juice both reduced conjugated diene formation. Moderate apple juice consumption provides in vivo antioxidant activity. In view of the current understanding of CAD, the observed effect on LDL might be associated with reduced CAD risk and supports the inclusion of apple juice in a healthy human diet.

Nonpharmacologic therapy for coronary artery atherosclerosis: results of primary and secondary prevention trials.

The association between abnormal serum lipoprotein levels and coronary atherosclerosis has been established by extensive clinical, experimental, and epidemiologic evidence. Recent angiographic trials in patients with coronary artery disease have demonstrated that improvement in serum lipids and other risk factors has a favorable effect on coronary lesions and reduces coronary events and interventions. Most trials of coronary disease prevention have used intensive pharmacologic therapy, but several have involved only nonpharmacologic intervention. The latter investigations include both primary and secondary prevention studies. Three controlled, nonpharmacologic primary prevention trials with long-term follow-up used dietary management aimed at lowering serum cholesterol levels; one trial also included smoking cessation, and one used a comprehensive approach to risk-factor modification. Serum cholesterol levels and other risk factors were significantly decreased in the intervention groups but were unaltered in the control populations. After periods of 5 to 10 years, reductions of 20% to 45% in coronary events were observed in the intervention groups compared with controls. Four secondary intervention trials examined the effect of nonpharmacologic therapy alone on coronary artery disease regression; three of these trials included control groups. All of the trials focused on reduction of elevated serum cholesterol levels with a low-fat diet, and several included interventions for other risk factors. Serum cholesterol levels fell by 14% to 24% in treated patients compared with 4% to 9% in controls. Although these trials were of relatively short duration (1 to 3 years) and included small numbers of patients (36 to 90), each demonstrated favorable effects on coronary lesions and three revealed clinical benefits.(ABSTRACT TRUNCATED AT 250 WORDS)

Translational nutrition research at UC Davis - the key role of the Clinical and Translational Science Center.

The National Institutes of Healths Clinical and Translational Science Award (CTSA) program has had a profound impact on clinical research and training methods at the University of California, Davis (UC Davis). UC Davis was among the first 12 institutions to receive NIH funding for this award, and created its Clinical and Translational Science Center (CTSC) in 2006. The funding accelerated and further integrated an existing conscientious and careful planning effort for translational research with a stepwise approach to gradually increase our institutional competencies, capabilities, and resources in this area. The development of our CTSC has led us to develop new ways of bringing together a diverse faculty and facilitating research. The CTSC has impacted virtually every area and infrastructure resource involved in promoting clinical and translational research at our institution.