Effects of Almond Intake on Atherogenic Lipoprotein Particles

NCT01792648 | Completed

• 1 other identifier: MM2222
• Study Type: interventional
• Target: 24
• Locations: 1 country
• Sites: 1

Brief Summary

Increased abdominal adiposity is a key feature of metabolic syndrome, which describes a cluster of cardiovascular disease (CVD) risk factors that also includes insulin resistance, high blood pressure and an atherogenic lipoprotein phenotype characterized by increased plasma triglycerides, low HDL-C, and increased levels of small LDL particles. While lifestyle intervention remains the cornerstone for managing obesity and metabolic syndrome, the optimal dietary macronutrient distribution for improving blood lipids and CVD risk remains a topic of controversy. While both low carbohydrate diets and weight reduction are effective for managing atherogenic dyslipidemia, long-term compliance is low, and it becomes imperative to identify alternative dietary approaches. Increased consumption of almonds has been shown to lower LDL-C, an effect that exceeds that predicted from changes in fatty acid intake. However, although LDL-C lowering by almonds has been demonstrated in patients with diabetes, there have been no trials in non-diabetic patients with abdominal obesity. Moreover, there is limited information of the effects of almond intake on LDL particle subclasses. The overall objective of the present study is to determine whether lipoprotein measures of CVD risk in individuals with increased abdominal adiposity are reduced by almond supplementation in a diet with overall macronutrient content that conforms to current guidelines. Our main hypothesis is that in these individuals, almond consumption can reduce levels of small and medium LDL particles without the need to restrict dietary carbohydrates to levels below those currently recommended. This hypothesis will be tested by comparing the lipoprotein effects of an almond-supplemented diet (20%E) with those of two reference diets that do not contain almond products: one with similar content of carbohydrate, protein, and fat (standard reference), and the other in which carbohydrate content is reduced by substitution of protein and monounsaturated fat (low-carbohydrate reference). We will provide the diets for 3 weeks each in a randomized 3-period crossover design to 40 individuals with increased abdominal adiposity. We will test whether the almond supplemented diet will result in lower levels of lipoprotein measures of CVD risk, specifically LDL-C and small and medium LDL particles, compared to either the standard or low-carbohydrate reference diets.

Conditions

Dyslipidemia; Obesity, Abdominal

Keywords

Almond; Carbohydrate; Diet; Cholesterol

Outcome Measures

Primary Outcomes (3)

• Change in Total and LDL cholesterol

  Change in total and LDL cholesterol between each of the 3 test diets

  3 weeks, 8 weeks, 13 weeks

• Change in small and medium LDL particles

  Change in small and medium LDL particles between each of the 3 test diets

  3 weeks, 8 weeks, and 13 weeks

• Change in apolipoprotein B

  Change in apolipoprotein B between each of the 3 test diets

  3 weeks, 8 week, 13 weeks

Secondary Outcomes (7)

• Change in total/HDL-cholesterol ratio

  3 weeks, 8 weeks, 13 weeks

• Change in LDL peak particle diameter

  3 weeks, 8 week, 13 weeks

• Change in plasma triglycerides

  3 weeks, 8 weeks, 13 weeks

• Change in HDL-cholesterol

  3 weeks, 8 weeks, 13 weeks

• Change in large HDL particles

  3 weeks, 8 weeks, 13 weeks

Study Arms (3)

Standard Reference Diet

ACTIVE COMPARATOR

Other: Standard reference diet

Almond Supplemented Diet

EXPERIMENTAL

Other: Almond supplemented diet

Low Carbohydrate Reference Diet

ACTIVE COMPARATOR

Other: Low carbohydrate reference diet

Interventions

Standard reference diet OTHER

50% energy as carbohydrate, 15% energy as protein, 35% energy as total fat

Standard Reference Diet

Almond supplemented diet OTHER

50% energy as carbohydrate, 15% energy as protein, 35% energy as total fat, 20% energy from almonds

Almond Supplemented Diet

Low carbohydrate reference diet OTHER

26% energy from carbohydrate, 29% energy from protein, 45% energy from total fat

Low Carbohydrate Reference Diet

Eligibility Criteria

• Age: 20 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 20 or older
• Increased abdominal adiposity as defined by waist circumference ≥102 for men or ≥88 for women.
• Fasting blood sugar (FBS) \< 126 mg/dl
• Weight stable for \> 3 months.

You may not qualify if:

• History of coronary heart disease, cerebrovascular disease, peripheral vascular disease, bleeding disorder, liver or renal disease, diabetes, lung disease, HIV, or cancer (other than skin cancer) in the last 5 years.
• Taking hormones or drugs known to affect lipid metabolism or blood pressure.
• Systolic blood pressure \> 160 mm Hg and diastolic blood pressure \> 95 mm Hg.
• Body mass index (BMI) \> 38 kg/m2
• User of nicotine products or recreational drugs
• Refusal to abstain from alcohol or dietary supplements during the study.
• Total- and LDL-C \> 95th percentile for sex and age.
• Fasting triglycerides \> 50mg/dl and \> 500 mg/dl
• Abnormal thyroid stimulating hormone (TSH) levels.
• Pregnant or breast-feeding

Sponsors & Collaborators

• UCSF Benioff Children's Hospital Oakland: lead
• Almond Board of California: collaborator

Study Sites (1)

Cholesterol Research Center

Berkeley, California, 94705, United States

Location

Related Publications (1)

• Williams PT, Bergeron N, Chiu S, Krauss RM. A randomized, controlled trial on the effects of almonds on lipoprotein response to a higher carbohydrate, lower fat diet in men and women with abdominal adiposity. Lipids Health Dis. 2019 Apr 3;18(1):83. doi: 10.1186/s12944-019-1025-4.

  PMID: 30943980 DERIVED

MeSH Terms

Conditions

Dyslipidemias; Obesity, Abdominal

Condition Hierarchy (Ancestors)

Lipid Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Obesity; Overweight; Overnutrition; Nutrition Disorders; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Ronald M Krauss, MD

  UCSF Benioff Children's Hospital Oakland

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 26, 2012
• First Posted: February 15, 2013
• Study Start: April 1, 2013
• Primary Completion: February 1, 2016
• Study Completion: April 1, 2016
• Last Updated: November 6, 2017

Record last verified: 2017-10

Locations

US (1)