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

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

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.

Study Overview

• Status: Completed
• Conditions: Cardiovascular Disease
• Intervention / Treatment: Behavioral: Food supplementation: nopales; Behavioral: Food supplementation: cucumber

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Actual): 27
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Arizona
    • Phoenix, Arizona, United States, 85004
      • Nutrition Laboratory at Arizona State University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Food supplementation: nopales; 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; Consumption of 2 cups/day of test food: nopales
Sham Comparator: Food supplementation: cucumber; Consumption of 2 cups/day peeled and chopped cucumber with each of two main meals for 2 weeks	Behavioral: Food supplementation: cucumber; Consumption of 2 cups/day of test food: cucumber

What is the study measuring?

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

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Vitamin C	Vitamin C concentration in plasma to assess compliance	Pre- and post- each 2-week phase

Collaborators and Investigators

• Sponsor: Arizona State University
• Investigators: Principal Investigator: Sonia Vega-López, PhD, Arizona State University

Study record dates

Study Major Dates

• Study Start: January 1, 2013
• Primary Completion (Actual): August 1, 2013
• Study Completion (Actual): March 1, 2014

Study Registration Dates

• First Submitted: August 4, 2014
• First Submitted That Met QC Criteria: August 4, 2014
• First Posted (Estimate): August 6, 2014

Study Record Updates

• Last Update Posted (Estimate): August 7, 2014
• Last Update Submitted That Met QC Criteria: August 5, 2014
• Last Verified: August 1, 2014

More Information

Terms related to this study

• Keywords: Prevention; Functional food; Dietary intervention; Hypercholesterolemic adults; Vegetable intake
• Additional Relevant MeSH Terms: Cardiovascular Diseases
• Other Study ID Numbers: Nopales-2014