Effect of Alpha-Linolenic Acid on Blood Markers of Inflammation
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 130
- 主要终点
- Markers of inflammation
研究概览
简要总结
The optimal type of oil to prevent cardiovascular disease (CVD) is uncertain. In general, unsaturated oils with higher content of cis-monounsaturated fatty acids (MONO) or cis-polyunsaturated fatty acids (PUFA) are preferable over those rich in saturated fatty acids. However, unsaturated oils can vary in their relative contents of n-6 and n-3 fatty acids (specifically alpha-linolenic acid (ALA)). Some investigators advocate that oils rich in ALA are cardioprotective, while others suggest that optimal cardioprotective effects can only be obtained when oils are lower in n-6 fatty acids (mainly linoleic acid) in addition to being higher in ALA. It is hypothesized that increased ALA would result in beneficial effects on inflammatory markers. The objective of this trial is to establish definitively the biological effects of ALA with and without reductions in linoleic acid on inflammatory markers linked to CVD.
详细描述
This study is a dietary trial that examines the effects of increasing ALA by 2 gr or 4 gr per day, with and without decreasing linoleic acid, on inflammatory markers linked to CVD. Trial participants (n=136), approximately 50% women, 50% men) are age 50 and older and living in the town of Montana, Bulgaria during the study. The study uses a double-blinded placebo-controlled, randomized cross-over design. Combinations of two oils that are considered healthy (sunflower and olive) and an ALA supplement containing either 2 or 4 gr of ALA (supplied as flaxseed oil) or placebo are consumed for 6 weeks each: sunflower-ALA (high linoleic-low ALA), sunflower-placebo (high linoleic-low ALA), olive-ALA (low-linoleic-high ALA) and olive-placebo (low linoleic-low ALA). The participants are indicated to keep their usual diet and physical activity through-out the study. The primary endpoints are plasma levels of inflammatory markers. Secondary endpoints include systolic and diastolic blood pressure, and plasma levels of LDL cholesterol, HDL cholesterol and triglycerides.
SPECIFIC AIMS
To determine the effect of increasing ALA by 2 or 4 gr per day in the context of a diet that that is high in linoleic acid (~13% energy) on inflammatory markers. The ALA effect will be tested by comparing ALA supplement vs. placebo while using sunflower oil for cooking at home. We hypothesize that ALA has favorable effects on inflammatory markers in the context of a diet that is high in linoleic acid.
To determine the effect of increasing ALA by 2 or 4 gr per day in the context of a diet that that is low in linoleic acid (~6% energy) on inflammatory markers. The ALA effect will be tested by comparing ALA supplement vs. placebo while using olive oil for cooking at home. We hypothesize that ALA has favorable effects on inflammatory markers in the context of a diet that is low in linoleic acid.
SECONDARY AIMS
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Prevention
- 盲法
- Triple (Participant, Care Provider, Investigator)
入排标准
- 年龄范围
- 50 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Age 50 or older at time of enrollment
- •Willing to cook and eat foods prepared exclusively with the study oils and nothing else every day of the week at least 2 meals per day for 24 weeks
- •Willing to eat no more than one meal per week prepared out of the home
- •Willingness to take 4 or 8 capsules with ALA or placebo every day for 24 weeks
- •Willingness to provide personal and next of kin address and phone number for follow-up visits to the home.
- •Willingness to complete measurement procedures and blood draws.
- •Ability and willingness to provide informed consent to be screened and to take part of the study.
排除标准
- •Medication Exclusions
- •Unstable dose of medications during the past 2 months that raise or lower blood pressure, lipids or glucose. Unstable dose is a dose change in the past 6 months or less than 6 months of treatment.
- •Medical History Exclusions
- •Active or prior CVD (stroke, MI, PTCA, CABG, congestive heart failure, symptomatic ischemic heart disease (angina), or CVD-related therapeutic procedure).
- •Cancer diagnosis or treatment in past two years (however, persons with non-melanoma skin cancer, localized breast cancer, or localized prostate cancer can enroll if they did not require systemic chemotherapy)
- •Active inflammatory bowel disease, malabsorption, or major GI resection
- •Chronic renal disease
- •Any serious illness not otherwise specified that would interfere with participation
- •Stage 2 hypertension (SBP > 160 or DBP > 100 mmHg) based on the mean of 3 measurements on the screening visit, as well as a systolic BP > 170 or diastolic BP > 105 at any of the measurements
- •Other Exclusions
- •Eat fish more than once per week including canned fish
- •Significant oil preferences, intolerances, dietary habits, or dietary requirements that would interfere with adherence
- •Planning to leave the area for more than two weeks prior to the anticipated end of participation
- •Current participation in another study that manipulates diet or that will affect the outcome of this study
- •Taking vitamin, vegetable oil, fish-oil, weight-loss, soy, mineral, or herbal supplements that cannot be stopped
- •Unable to measure blood pressure (due to arm circumference > 50 cm)
- •Investigator judgment (e.g. for concerns over adherence, or follow-up or for inappropriate behavior)
结局指标
主要结局
Markers of inflammation
时间窗: 6 weeks
次要结局
- Plasma lipids and blood pressure(6 weeks)