Evaluating the Effects of Omega-3 Fatty Acids on Heart Disease and Behavior

BioBehavioral Studies of Cardiovascular Disease

Omega-3 fatty acids are a certain kind of fish fat that has recently been shown to have health benefits. This study will examine the effectiveness of fish oil supplementation for reducing the early signs of heart disease risk and for improving mood, impulsivity, and anger levels.

Cardiovascular disease (CVD) is a broad term that includes diseases that affect the heart and blood vessels, including coronary heart disease, heart failure, high blood pressure, stroke and vascular dementia. CVD is the leading cause of death in the United States, resulting in 700,000 deaths each year. Preliminary research has shown that increased consumption of fish, specifically the omega-3 fatty acids found in fish oil, has beneficial effects in people with CVD. Fish oil may also have positive effects on the psychological health and well-being of people with psychiatric disorders. However, more research is needed to confirm the positive physical and psychological effects of fish oil in healthy adults. The purpose of this study is to explore potentail effects of fish oil supplementation on CVD mechanisms and risk markers, and on depressive symptoms, antagonistic disposition, and levels of impulsivity and aggression.

This study will enroll healthy adults who habitually consume low quantities of long-chain omega-3 fatty acids. Participants will be randomly assigned to receive either fish oil supplements or placebo on a daily basis for 4 months. Study visits will occur at baseline and Months 2 and 4. At the baseline and Month 4 visits, participants will undergo the following measures as primary study aims: blood collection for inflammatory markers; heart rate and variability measurements; and interviews, psychological tests, and questionnaires to assess mood, disposition, impulsivity, and aggression.

As secondary aims, we will test for any effects of fish oil on cognitive performance and, if a main effect on inflammatory markers is found, we will test for moderation by select genetic polymorphisms.

As an exploratory aim, we will test for any effects of fish oil on structural or functional brain imaging. (This exploratory aim was mistakenly listed as a secondary aim at the time of trial registration.)

Inclusion Criteria:

• Currently employed at least 25 hours a week, but does not regularly work the third shift (i.e., night shift)
• English is primary language
• Consumes less than 300 mg/day of long-chain omega-3 fatty acids.

Exclusion Criteria:

• Serious allergy to fish (e.g., anaphylaxis, bronchospasm, serious skin reaction)
• History of atherosclerotic disease (e.g., myocardial infarction) or treatment of angina or claudication (e.g., angioplasty)
• Reported history of schizophrenia or bipolar disorder
• Long-term hepatitis
• Kidney failure
• Stroke or other neurological disorder
• Lung disease requiring drug treatment
• Stage 2 high blood pressure, defined as systolic blood pressure of 160 mm Hg or greater and diastolic blood pressure of 100 mm Hg or greater
• Alcohol consumption of more than five drinks per day each week (i.e., more than 35 alcoholic drinks each week)
• Pregnant or breastfeeding
• Currently taking any cardiovascular, psychotropic, glucocorticoid, lipid-lowering, insulin, or weight loss medications
• Currently taking fish oil supplements