Effects of Almond Intake on Atherogenic Lipoprotein Particles

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

Interventions

OTHER

Standard reference diet

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

OTHER

Almond supplemented diet

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

OTHER

Low carbohydrate reference diet

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

Sponsors & Collaborators

• Almond Board of California

  collaborator OTHER

• UCSF Benioff Children's Hospital Oakland

  lead OTHER

Principal Investigators

• Ronald M Krauss, MD · UCSF Benioff Children's Hospital Oakland

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

CROSSOVER

Eligibility

Min Age

20 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2013-04-30

Primary Completion

2016-02-29

Completion

2016-04-30

Countries

• United States

Study Locations