Effects of Nopales (Opuntia Spp.) on Lipoprotein Profile and Oxidative Stress in Moderately Hypercholesterolemic Adults

Study Overview
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Brief Summary
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In light of the high CVD morbidity and mortality, promoting simple interventions to improve serum lipids and decrease oxidative stress are warranted to help prevent chronic diseases. Because of their fiber content, nopales (prickly pear cactus pads from the Opuntia species) are commonly regarded among Mexicans as a medicinal plant for glycemic and cholesterol control. However, the literature documenting their purported hypocholesterolemic potential is scarce. Given the unique composition and potential benefits of nopales, their use may be an ideal approach as an adjunct therapy for the reduction in cardiometabolic risk factors. Therefore, the aim of this study is to evaluate the efficacy of a 2-week intervention with nopales pads for the reduction of established CVD risk factors (serum lipids) in comparison to a control food with lower antioxidant and fiber content (cucumber) among adults with moderate hypercholesterolemia in a randomized controlled crossover trial. Because limited data exists on the effects of nopales supplementation on other factors associated with cardiometabolic risk, an exploratory assessment of how biomarkers of insulin sensitivity, inflammation (high sensitivity C-reactive protein [hsCRP]) and oxidative stress (LDL oxidizability and total antioxidant capacity) will also be conducted.

Detailed Description
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In light of the high cardiovascular disease morbidity and mortality, promoting simple interventions to improve serum lipids and decrease oxidative stress are warranted to help prevent chronic diseases. Commonly prescribed dietary interventions for cardiovascular disease risk reduction include the use of functional foods known to have beneficial effects on risk factors. Because of their fiber content, nopales (prickly pear cactus pads from the Opuntia species) are commonly regarded among Mexicans as a medicinal plant for glycemic and cholesterol control. However, the literature documenting their purported hypocholesterolemic potential is scarce. Most studies have focused on the prickly pear fruit, rather than the actual nopales cactus pads. Given the unique composition and potential benefits of nopales, their use may be an ideal approach as an adjunct therapy for the reduction in cardiometabolic risk factors. The aim of this study is to evaluate the efficacy of a 2-week intervention with nopales pads for the reduction of established CVD risk factors (serum lipids) in comparison to a control food with lower antioxidant and fiber content (cucumber) among adults with moderate hypercholesterolemia in a randomized controlled crossover trial. Because limited data exists on the effects of nopales supplementation on other factors associated with cardiometabolic risk, an exploratory assessment of how biomarkers of insulin sensitivity, inflammation (high sensitivity C-reactive protein [hsCRP]) and oxidative stress (LDL oxidizability and total antioxidant capacity) will also be conducted. In this randomized crossover trial, healthy adults with moderate hypercholesterolemia (LDL-cholesterol ≥ 120 mg/dL) but otherwise healthy will be randomly assigned to supplementation with 2 cups/day of nopales (300 g; intervention) or cucumbers (208 g; control), divided into two 1 cup daily doses with each of two main meals. After a 3-week washout period, each group will receive the alternative treatment for an additional 2 weeks. Participants will be asked to refrain from making any additional changes to their usual diet throughout the duration of the entire study. Fasting blood samples will be collected at the beginning and end of each dietary intervention. At the beginning and end of each dietary intervention an additional fasting blood sample will be collected at least one day apart from the main blood collection day for measurement of serum lipids to account for day-to-day variability. Outcome measures include a complete lipid panel (total cholesterol, HDL-c, LDL-c, and triglycerides), fasting glucose, insulin, oxidized LDL and LDL susceptibility to oxidation, total antioxidant capacity (TAC), and vitamin C.

Official Title
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The Efficacy of Nopales (Opuntia Spp.) on Lipoprotein Profile and Oxidative Stress Among Moderately Hypercholesterolemic Adults

Conditions
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Cardiovascular Disease

Intervention / Treatment
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* Behavioral: Food supplementation: nopales
* Behavioral: Food supplementation: cucumber


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Moderate hypercholesterolemia (LDL cholesterol ≥ 120 mg/dL) Exclusion Criteria: Use of hypolipidemic medications Regular physical activity (≥ 30 min /day for ≥ 5 days/week) Presence of known chronic diseases (e.g., diabetes, CVD, cancer, hepatitis, inflammatory conditions, gastrointestinal disorders) Consumption of > 4 servings/day of fruits and vegetables Following a restrictive diet (e.g., carbohydrate restriction, veganism) or having any condition likely to require specialized dietary modifications Use of supplements (antioxidants, fiber and botanicals) Latex allergy Fear of needles Breastfeeding, pregnancy, or intent to become pregnant Unwillingness to comply with study protocol Participation in other research studies.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Food supplementation: nopales<br>Consumption of 2 cups/day of cooked nopales (prickly pear cactus leaves) with each of two main meals for 2 weeks | Behavioral: Food supplementation: nopales<br>* Consumption of 2 cups/day of test food: nopales<br>|
| Sham Comparator: Food supplementation: cucumber<br>Consumption of 2 cups/day peeled and chopped cucumber with each of two main meals for 2 weeks | Behavioral: Food supplementation: cucumber<br>* Consumption of 2 cups/day of test food: cucumber<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Plasma lipids | Total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides. | Pre- and post- each 2-week phase | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Glucose | Plasma glucose | Pre- and post- each 2-week phase | 
| Distribution of cholesterol in LDL and HDL subfractions | Distribution of cholesterol among seven LDL and ten HDL subfractions. | After each 2-week phase | 
| Oxidized LDL | Amount of oxidized LDL as measured by ELISA and LDL oxidizability as measured by conjugated diene formation. | Pre- and post- each 2-week phase | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Dietary intervention, Hypercholesterolemic adults, Vegetable intake, Functional food, Prevention