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Heart & Health Study

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ClinicalTrials.gov Identifier: NCT00536185
Recruitment Status : Completed
First Posted : September 27, 2007
Last Update Posted : August 4, 2011
Information provided by:

Study Description
Brief Summary:

We hope to learn more about why certain people have higher levels of the 5-LO protein and whether taking fish oil supplements gives such individuals greater protection than others against cardiovascular disease. The 5-LO protein is important in the development of heart disease because it converts a type of oil from meat into a compound that can cause inflammation in blood vessels. This inflammation is a major cause of heart disease.

Researchers think that people with higher levels of a protein called 5-LO in their white blood cells may have a healthier response to using fish oil supplements than do people with lower levels of this protein.

Condition or disease Intervention/treatment
Heart Disease Dietary Supplement: Fish Oil Dietary Supplement: Placebo

Detailed Description:

Fish oil supplements will be given to subjects with different variants in the promoter region of the arachidonate 5-lipoxygenase (ALOX5) gene and outcome measures will be evaluated after 6 wk of supplementation. These outcomes include ALOX5 protein levels (also called 5-lipoxygenase, or 5-LO), leukotriene levels, markers of inflammation, and blood lipids. The 5-LO enzyme converts arachidonic acid (AA) to leukotrienes that promote inflammation. Subjects with different promoter variants are hypothesized to have different basal or stimulated levels of 5-LO expression. Preliminary data suggests that subjects with a promoter variant that causes increased 5-LO expression also may have a "better" anti-inflammatory or lipid-lowering response to fish oil supplements. The homozygous variant genotype is much more common in African Americans than other groups thus we propose to conduct the study in African Americans. The fish oil eicosapentaenoic acid (EPA) competitively inhibits conversion of AA to pro-inflammatory 4-series leukotrienes.

The grant proposes to conduct a community-based, double-masked, randomized, placebo-controlled trial; n = 15/group, total = 166 (genotypes 44 will have n = 8). The intervention group will receive 5.0 g/d fish oil concentrate (3.0 g/d EPA + DHA) for 6 wk. The study will be conducted in Oakland, Davis, and Sacramento, California where African Americans 20 - 59 y of age without serious chronic disease will be recruited.

A recent observational study indicates that subjects with a variant allele for ALOX5 may be at greater risk for cardiovascular disease and, at the same time, may derive a greater benefit from omega-3 fatty acid supplements than do subjects homozygous for the common allele. The variant alleles are less common in the white population (18%) than in the black population (52%). Since African Americans have a higher prevalence of cardiovascular disease and of the ALOX5 variant alleles, as shown in epidemiologic studies, they may have a greater benefit from omega-3 supplementation in the reduction of inflammation and cardiovascular risk factors. Recruitment will be conducted through the community service, Ethnic Health Institute (EHI), of Alta Bates Summit Medical Center in conjunction with UCD, and outreach efforts from the USDA, ARS, Western Human Nutrition Research Center (WHNRC) at UC Davis. We will determine if subjects with one or two variant ALOX5 alleles have higher ALOX5 gene expression, higher production of AA-derived leukotrienes, and a better response to omega-3 supplements than do subjects homozygous for the common allele.

Study Design

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 166 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: Variation in the ALOX5 Gene and Response to Omega-3 Fatty Acid Supplements
Study Start Date : December 2006
Primary Completion Date : July 2008
Study Completion Date : July 2008

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Heart Diseases
U.S. FDA Resources

Arms and Interventions

Arm Intervention/treatment
Experimental: 1 Dietary Supplement: Fish Oil
capsules, 5.0 g/d fish oil concentrate (3.0 g/d EPA + DHA), 6 weeks
Placebo Comparator: 2 Dietary Supplement: Placebo
capsule, 5.0 g/d corn/soybean oil (50/50 mixture), 6 weeks

Outcome Measures

Primary Outcome Measures :
  1. (a) ALOX5 mRNA and protein in resting and stimulated cultures of purified monocytes and purified granulocytes (b) Arachidonic acid-derived leukotrienes in resting and stimulated cultures of whole blood, purified monocytes and purified granulocytes [ Time Frame: 6 weeks ]

Secondary Outcome Measures :
  1. Proinflammatory cytokines, C-reactive protein, triglycerides, glucose and insulin in plasma, and resting heart rate and blood pressure [ Time Frame: 6 weeks ]

Eligibility Criteria

Information from the National Library of Medicine

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Ages Eligible for Study:   20 Years to 59 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • African-American, Black, or persons of African Descent
  • Generally Healthy
  • 20 - 59 years of age

Exclusion Criteria:

  • Chronic Diseases (Heart disease, cancer, diabetes, etc.)
  • Smoke > 14 cigarettes per week
  • Consume > 14 alcoholic drinks per week
  • Pregnant Women
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00536185

United States, California
UC Davis, Western Human Nutrition Research Center
Davis, California, United States, 95616
Ethnich Health Institute
Oakland, California, United States, 94609
UC Davis (TICON-1)
Sacramento, California, United States, 95820
Sponsors and Collaborators
USDA, Western Human Nutrition Research Center
National Center for Complementary and Integrative Health (NCCIH)
Office of Dietary Supplements (ODS)
University of California, Davis
United States Department of Agriculture (USDA)
Alta Bates Summit Medical Center
University of Southern California
Principal Investigator: Charles B Stephensen, PhD UC Davis & U.S. Department of Agriculture
More Information

Additional Information:
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Charles Bolt Stephenson, PhD, Western Human Nutrition Resource Center
ClinicalTrials.gov Identifier: NCT00536185     History of Changes
Other Study ID Numbers: R21AT003411-01A1 ( U.S. NIH Grant/Contract )
First Posted: September 27, 2007    Key Record Dates
Last Update Posted: August 4, 2011
Last Verified: August 2011

Keywords provided by USDA, Western Human Nutrition Research Center:
Heart Disease

Additional relevant MeSH terms:
Heart Diseases
Cardiovascular Diseases