Response of Cardiometabolic Biomarkers and Gut Microbiota to Walnut Consumption
试验速览
- 阶段
- 不适用
- 状态
- 进行中（未招募）
- 入组人数
- 30
- 试验地点
- 1
- 主要终点
- Assessing the influence of walnut consumption on blood lipid measurements.
研究概览
简要总结
The purpose of this research is to test if eating walnuts will cause any changes in blood lipids (like good and bad cholesterol, for example) and levels of inflammation in the blood, as well as changes in the bacteria living in the gut.
详细描述
The purpose of this research is to test if eating walnuts will cause any changes in blood lipids (like good and bad cholesterol, for example) and levels of inflammation in the blood, as well as changes in the bacteria living in the gut. Overweight/obese adults between the ages of 45 and 70 yo with elevated LDL-C levels are eligible to participate. The study involves 5 visits (1 initial screening and 4 study visits) and will last about 10 weeks. There is a 1-week run-in period before starting the study, followed by two diet intervention periods each lasting 3 weeks, separated by a 3-week washout period.
Participation in this study will involve an initial 1-week run in period to become accustomed to the study diet. After this 1 week period, participants will be randomly selected to start either a walnut or a no-nut diet. During each phase of the study, participants will be asked to come to the University of California, Davis campus after a 10-12 hour overnight fast. At each visit, body measurements will be taken; blood, urine and fecal samples will be collected.
During the 10 weeks of the study, all nuts and nut-derived products will need to be avoided. The study will provide walnuts to be eaten at home for each intervention phase. Additionally, the investigators will ask that ellagitannin-rich foods, high-fiber and fermented foods be avoided in the diet. Detailed food diaries will be filled out and brought to study visits.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 45 Years 至 70 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Overweight and obese men and postmenopausal women between 45-70 years of age, BMI range of 25.0-39.9 kg/m2 and elevated LDL-C levels (130-189 mg/dL).
排除标准
- •Adults unable to consent, individuals who are not yet adults (infants, children, teenagers), pregnant or lactating women, women planning to become pregnant in the next four months and prisoners will be specifically excluded.
- •Additional exclusion criteria are listed below:
- •Allergy to walnuts or other nuts
- •Eating more than 25 grams of fiber per day, assessed by the Block Dietary-Fruit-Vegetable-Fiber Screener©
- •Taking medications or supplements known to affect metabolism or gut microbiota composition (i.e. Metformin, statins, antibiotics within the past 3 months, fiber supplements, probiotics, and others)
- •Documented chronic diseases including diabetes, renal or liver disease, metabolic syndrome, active cancer, MI or stroke, history of gastric bypass or GI disease (e.g. Crohn's Disease, Irritable Bowel Disease, diverticulosis, diverticulitis, etc.)
- •Smoker or living with a smoker, including vaporizer and/or electronic cigarettes.
- •Illicit drug use, cannabis usage, or consuming >1 alcoholic drink/day
- •Extreme dietary or exercise patterns
- •Recent weight fluctuations (>10% in the last 6 months)
- •Taking prescription lipid medications or supplements that may affect lipoprotein metabolism (i.e. >1 g of fish oil/day, antioxidant supplements)
- •Taking exogenous hormones
- •Poor venous access
- •Unwillingness to comply with study protocols
研究组 & 干预措施
Walnut diet
Participants will consume 56 g of walnuts each day at home for 3 weeks.
干预措施: Walnuts (Dietary Supplement)
No-nut diet
Participants will follow a no-nut diet for 3 weeks.
干预措施: No-nut diet (Dietary Supplement)
结局指标
主要结局
Assessing the influence of walnut consumption on blood lipid measurements.
时间窗: Through study completion, an average of 10 weeks
Measure for changes in the levels of HDL and LDL in separated plasma; measured in units of mg/dL. Blood will be assessed for the fasting (baseline) sample at each of the 4 study visits.
Assessing the influence of walnut consumption on blood pressure.
时间窗: Through study completion, an average of 10 weeks
Measure blood pressure (mmHg) before the start of drawing blood on study day protocols.
Assessing the influence of walnut consumption on circulating inflammatory markers: PAI-1, VCAM-1 and ICAM-1.
时间窗: Through study completion, an average of 10 weeks
Measure circulating inflammatory markers in separated plasma at each of the 4 study visits. Commercially available ELISA kits will be used: PAI-1, VCAM-1, ICAM-1.
次要结局
- Assessing the influence of walnut consumption on fecal pH.(Through study completion, an average of 10 weeks)
- Assessing the influence of walnut consumption on stool consistency.(Through study completion, an average of 10 weeks)
- Assessing the influence of walnut consumption on fecal moisture.(Through study completion, an average of 10 weeks)
- Assessing the influence of walnut consumption on the levels of gut inflammatory markers: Lipocalin-2 and calprotectin.(Through study completion, an average of 10 weeks)
- Assessing the influence of walnut consumption on plasma and urine levels of walnut-derived metabolites - urolithins.(Through study completion, an average of 10 weeks)