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.)
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
SUPPORTIVE_CARE
Masking
DOUBLE
Enrollment
272
Participants will take 2 grams (1400 mg EPA and DHA) of fish oil supplements on a daily basis.
Participants will take 2 grams of soybean oil supplements on a daily basis.
University of Pittsburgh
Pittsburgh, Pennsylvania, United States
Circulating Serum Interleukin-6 (IL-6)
Systemic inflammation: fasting serum Interleukin-6 (IL-6)
Time frame: Baseline and Month 4
C-reactive Protein (CRP)
fasting serum C-reactive protein (CRP) in milligrams per liter (mg/L)
Time frame: baseline and month 4
Negative Affect
Negative affect questions adapted from the Positive and Negative Affect Schedule - Expanded Form administered via ecological momentary assessment. The minimum value is 1, and the maximum value is 6. A higher score are worse (more negative affect).
Time frame: baseline and month 4
Impulsivity
Barratt Impulsiveness Scale. The minimum value is 34, and the maximum value is 120. A higher score suggests a worse outcome.
Time frame: baseline and month 4
Aggression
Bus-Perry Aggression Questionnaire. The minimum value is 14, and the maximum value is 53. A higher score suggests a worse outcome.
Time frame: baseline and month 4
Hostility, Barefoot Score
The 27-item Barefoot Hostility Scale. The minimum value is 1, and the maximum value is 30. A higher score suggests a worse outcome.
Time frame: baseline and month 4
Trait Anger
State-Trait Anger Expression Inventory. The minimum value is 10, and the maximum value is 40. A higher score suggests a worse outcome.
Time frame: baseline and month 4
Anger Expression
State-Trait Anger Expression Inventory. The minimum value is 0, and the maximum value is 72. A higher score suggests a worse outcome.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Time frame: baseline and month 4
Type A, Total Score
Structured Interview - Type A Behavior Pattern using the Interpersonal Hostility Assessment Technique (IHAT). The minimum value is 0, and the maximum value is 12. A higher score suggests a worse outcome.
Time frame: baseline and month 4
Mean Successive Difference in Inter-beat Intervals Natural Log Transformed Paced Respiration
Mean successive difference in inter-beat intervals natural log transformed paced respiration in milliseconds
Time frame: baseline and month 4
High Frequency (.12 to .40 Hz) Heart Rate Variability Natural Log Transformed Paced Respiration
High frequency (.12 to .40 Hz) heart rate variability natural log transformed paced respiration in Hertz units (Hz)
Time frame: baseline and month 4
Total Power (0 to .40 Hz) Heart Rate Variability Natural Log Transformed Paced Respiration
Total power (0 to .40 Hz) heart rate variability natural log transformed paced respiration in Hertz (Hz) units.
Time frame: baseline and month 4
Mean Successive Difference in Inter-beat Intervals Natural Log Transformed Unpaced Respiration
Mean successive difference in inter-beat intervals natural log transformed unpaced respiration in milliseconds (msec)
Time frame: baseline and month 4
High Frequency (.12 to .40 Hz) Heart Rate Variability Natural Log Transformed Unpaced Respiration
High frequency (.12 to .40 Hz) heart rate variability natural log transformed unpaced respiration in Hertz (Hz) units
Time frame: baseline and month 4
Total Power (0 to .40 Hz) Heart Rate Variability Natural Log Transformed Unpaced Respiration
Total power (0 to .40 Hz) heart rate variability natural log transformed unpaced respiration in Hertz (Hz) units
Time frame: baseline and month 4
Executive Function
Executive function was comprised of trail making B - A time, digit span forward and digit span backward completions. Performance scores on each task were converted into Z-scores, and then averaged across tasks. The Z-score indicates the number of standard deviations away from the mean. A Z-score of 0 is equal to the mean with negative numbers indicating values lower than the mean and positive values higher. Higher Z scores indicate higher function (better outcome). The analysis compared changes in Z-scores between the two treatment groups.
Time frame: Baseline and Month 4
Learning / Episodic Memory
Learning/episodic memory was comprised of d' from the four word memory task and the average performance across all trials of the Rey auditory verbal learning test. Performance scores on each task were converted into Z-scores, and then averaged across tasks. The Z-score indicates the number of standard deviations away from the mean. A Z-score of 0 is equal to the mean with negative numbers indicating values lower than the mean and positive values higher. Higher Z scores indicate higher function (better outcome). The analysis compared changes in Z-scores between the two treatment groups.
Time frame: Baseline and Month 4
Psychomotor Speed
Psychomotor speed was comprised of trail making A time, Stroop word-only time and color-only time. Performance scores on each task were converted into Z-scores, and then averaged across tasks. The Z-score indicates the number of standard deviations away from the mean. A Z-score of 0 is equal to the mean with negative numbers indicating values lower than the mean and positive values higher. Higher Z scores indicate higher function (better outcome). The analysis compared changes in Z-scores between the two treatment groups.
Time frame: Baseline and Month 4
Fluid Intelligence
This outcome was based upon matrix reasoning task raw score, block design task raw score and spatial span forward raw score. Performance scores on each task were converted into Z-scores, and then averaged across tasks. The Z-score indicates the number of standard deviations away from the mean. A Z-score of 0 is equal to the mean with negative numbers indicating values lower than the mean and positive values higher. Higher Z scores indicate higher function (better outcome). The analysis compared changes in Z-scores between the two treatment groups.
Time frame: Baseline and Month 4
Moderation of Effects of Fish Oil on Inflammatory Markers by Select Genetic Polymorphisms
Circulating serum concentrations of IL6 and CRP before and after supplementation with fish oil or placebo.
Time frame: Measured at Month 4