Omega-3 Fatty Acids and Subconcussive Head Impacts

Mechanistic Investigation of Omega-3 Fatty Acids Pretreatment Effects on Subconcussive Brain Injury

The purpose of the proposed double-blind, randomized placebo-controlled trial is to understand how supplementation with fish oil [docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)] promote brain health against soccer heading. The study involves taking DHA+EPA or placebo, questionnaires, blood draws, brain imaging, tests to evaluate heart function, and soccer headings.

Study Overview

• Status: Recruiting
• Conditions: Omega-3 Fatty Acids; Subconcussive Head Impact
• Intervention / Treatment: Dietary supplement: Organic soybean oil; Other: Soccer Heading Model; Dietary supplement: Omega-3 Fatty Acids (EPA plus DHA)

Detailed Description

The purpose of the proposed study is to determine whether, and to what extent, supplementation with omega-3 fatty acids [docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)] can maintain or promote neural wellbeing against repetitive subconcussive head impacts. This study will also characterize what aspects of brain cellular and physiologic resiliencies are enhanced by supplementation in adult soccer players (aged 18-30 years old). A sub-cohort of participants who meet criteria for ADHD diagnosis will be part of exploratory analysises.

• Study Type: Interventional
• Enrollment (Estimated): 208
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Kei Kawata; Phone Number: 812-855-5244; Email: kkawata@indiana.edu

Study Locations

• United States
  • Indiana
    • Bloomington, Indiana, United States, 47405
      • Recruiting
      • Indiana University School of Public Health
      • Contact: Kei Kawata; Phone Number: 812-855-5244; Email: kkawata@indiana.edu
      • Principal Investigator: Kei Kawata

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Between age 18-30
• Current or former soccer player
• At least 5 years of soccer heading experience
• Have internet access
• Willing to commit to avoid any sport activity that purposefully uses one's head to maneuver during the study period (American football, ice-hockey, rugby, wrestling, and soccer heading).

Exclusion Criteria:

• Any head or neck injury within 6 months before the study
• Implanted metal/magnetic devices (e.g., orthodontic braces
• Diagnosed autonomic or cardiovascular diseases (e.g., hypertension)
• Consuming oily fish (2 servings or more/month: salmon, bluefin, swordfish, anchovies)
• Allergy to fish or shellfish
• Consuming omega-3 FA supplements including plant-based (e.g., flaxseed) in the past 3 months.
• Pregnancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo: Organic soybean oil pills; We will use organic soybean oil pills ) as a placebo condition for the DHA+EPA group. One capsule contains 485 mg of organic soybean oil, including negligible amounts of DHA (1.1 mg), EPA (1.7 mg), and vitamin E (10 mg). Participants will ingest 5 capsules daily. Soybean oil is one of the most widely used vegetable oils in the world. Soybean oil contains polyunsaturated fats and 18-carbon omega-3 FA (total omega-3 FA of 73.9 mg per capsule), but very low levels of DHA and EPA, which makes it an excellent placebo counterpart when evaluating the effects of DHA/EPA. The placebo capsule's shelf life, composition, shape, size as the DHA+EPA active comparator.	Dietary supplement: Organic soybean oil; We will use organic soybean oil pills ) as a placebo condition for the DHA+EPA group. One capsule contains 485 mg of organic soybean oil, including negligible amounts of DHA (1.1 mg), EPA (1.7 mg), and vitamin E (10 mg). Participants will ingest 5 capsules daily. Soybean oil is one of the most widely used vegetable oils in the world. Soybean oil contains polyunsaturated fats and 18-carbon omega-3 FA (total omega-3 FA of 73.9 mg per capsule), but very low levels of DHA and EPA, which makes it an excellent placebo counterpart when evaluating the effects of DHA/EPA. The placebo capsule's shelf life, composition, shape, size as the DHA+EPA active comparator.; Other: Soccer Heading Model; A standardized and reliable soccer heading protocol will be used for the experiment. A triaxial accelerometer (G-force tracker) embedded in a head-band pocket and positioned directly below the external occipital protuberance (inion) to monitor linear and rotational head accelerations. A JUGS soccer machine will be used to simulate a soccer throw-in with a standardized ball speed of 30 mph. The ball speed is similar to when soccer players make a long throw-in from the sideline to mid-field. Soccer players frequently perform this maneuver during practice and games. Subjects will stand approximately 40ft away from the machine to perform the heading. Participants perform 20 headers with 1 header per 30 seconds. The subjects will be instructed to direct the ball back toward the JUGS soccer machine in the air.
Active Comparator: Omega-3 Fatty Acids (EPA plus DHA); DHA+EPA capsules contain purified deep-sea fish oil, made from 100% wild-caught sardines and anchovies with a 3-year shelf life. The capsule shell is made from bovine limed bone with a size of 20 oblongs. Each soft gel capsule contains 480 mg of DHA, 205 mg of EPA, 145 mg of other omega-3 FA, and 10 mg of vitamin E. Participants in the DHA+EPA group will ingest 5 capsules daily [a total of 3.4 g/d: DHA (2.4 g), EPA (1.0 g)].	Other: Soccer Heading Model; A standardized and reliable soccer heading protocol will be used for the experiment. A triaxial accelerometer (G-force tracker) embedded in a head-band pocket and positioned directly below the external occipital protuberance (inion) to monitor linear and rotational head accelerations. A JUGS soccer machine will be used to simulate a soccer throw-in with a standardized ball speed of 30 mph. The ball speed is similar to when soccer players make a long throw-in from the sideline to mid-field. Soccer players frequently perform this maneuver during practice and games. Subjects will stand approximately 40ft away from the machine to perform the heading. Participants perform 20 headers with 1 header per 30 seconds. The subjects will be instructed to direct the ball back toward the JUGS soccer machine in the air.; Dietary supplement: Omega-3 Fatty Acids (EPA plus DHA); DHA+EPA capsules contain purified deep-sea fish oil, made from 100% wild-caught sardines and anchovies with a 3-year shelf life. The capsule shell is made from bovine limed bone with a size of 20 oblongs. Each soft gel capsule contains 480 mg of DHA, 205 mg of EPA, 145 mg of other omega-3 FA, and 10 mg of vitamin E. Participants in the DHA+EPA group will ingest 5 capsules daily [a total of 3.4 g/d: DHA (2.4 g), EPA (1.0 g)].

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood Biomarkers	The primary outcome analyses will be comparing group differences (group x time interactions) in blood biomarkers, specifically NF-L (neurofilament light, ), tau (picogram per milliliter), GFAP (glial fibrillary acidic protein; nanograms per milliliter), UCH-L1 (ubiquitin C-terminal hydrolase-L1; picograms per milliliter), and S100B (S100 calcium binding protein B; nanograms per milliliter). The aggregation of all blood biomarkers will provide a comprehensive overview of the biofluid profile of the participant following repetitive head injury.	Baseline, 24 hours following 1st and 2nd heading sessions, 7 days following the 2nd heading session
Diffusion Tensor Imaging	DTI will be used to derive mean diffusivity (MD; square millimeters per second) and fractional anisotropy (FA; a unitless value that ranges from 0 to 1, 0 = Isotropic, 1= Anisotropic) as indicators joint of axonal integrity (axonal microstructure) and connectivity of white matter tracts by measuring how water molecules move through brain tissues .	Baseline, 24 hours following 1st and 2nd heading sessions, 7 days following the 2nd heading session
Sympathetic Reactivity	Sympathetic Reactivity will be measured by the Cold Pressor Test (CPT). CPT is a general assessment of the ability of the sympathetic nervous system to become activated. The main metric will be changes in mean arterial pressure (MAP) following soccer headings. This test will be performed by submerging a participants hand into cold water for 2 minutes while autonomic and hemodynamic variables are recorded. At each data collection, participants will be instrumented for the measurement of heart rate (electrocardiogram) and continuous blood pressure. Participants will rest quietly for ~10 minutes before the CPT begins. The test takes 2 minutes.	Baseline, 24 hours following 1st and 2nd heading sessions, 7 days following the 2nd heading session
Near Point Convergence	Using the accommodative ruler, a target (14-point letter) will be moved toward the eyes at a rate of 1-2 cm/s. NPC will be recorded when participants report diplopia has occurred, or the tester observes eye misalignment. The assessment will be repeated twice, and the mean near point convergence value will be used for analyses.	Baseline, 24 hours following 1st and 2nd heading sessions, 7 days following the 2nd heading session
King-Devick test	The King-Devick test (KDT) consists of a total of 145 saccades while rapidly reading numbers aloud to complete the test. The KDT will be administered on a tablet. The total time (in seconds) will be used for analysis.	Baseline, 24 hours following 1st and 2nd heading sessions, 7 days following the 2nd heading session

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Heart rate variability	Leading up to and during the cold pressor test (CPT) heart rate will be monitored via 3-lead ECG. Resting-state heart rate variability and spontaneous cardiovagal baroreflex sensitivity (cBRS) will be monitored over the last 5 minutes before the CPT. Using the R-R interval data collected from the ECG recordings during 5 minutes of paced breathing, time domain analyses will be performed to estimate overall heart rate variability and provide insight into cardiac parasympathetic activity.	Baseline, 24 hours following 1st and 2nd heading sessions, 7 days following the 2nd heading session
Cardiovagal baroreflex sensitivity	Spontaneous cardiovagal baroreflex sensitivity (cBRS) will be collected over the last 5 minutes before the CPT. Baroreflex sequences of 4 consecutive cardiac cycles will be captured using WinCPRS software, for which directional changes in the R-R interval and corresponding systolic blood pressure will be identified. Sequences will be detected when changes in systolic blood pressure are ≥1mmHg and the variation in R-R interval is ≥5miliseconds. Only sequences with an R2 ≥0.85 will be deemed acceptable. The mean of the regression slope will be calculated as the cBRS gain and used for analysis	Baseline, 24 hours following 1st and 2nd heading sessions, 7 days following the 2nd heading session
Quantitative Susceptibility Mapping	Quantitative Susceptibility Mapping of whole brain, as well as regions of interest analysis, will be conducted to inspect the tissue and brain architectural response to head impacts and omega-3 fatty acid supplementation.	Baseline, 24 hours following 1st and 2nd heading sessions, 7 days following the 2nd heading session
Metabolomics	Mitochondrial respiration related metabolites, including pyruvate, acetyl-CoA, citrate, isocitrate, alpha-ketogluterate, succinyl-CoA, succinate, fumarate, malate, and oxaloacetate will be assessed on blood samples. The aggregation of all metabolomic data will provide a comprehensive overview of the homeostasis of the participant following repetitive head injury.	Baseline, 24 hours following 1st and 2nd heading sessions, 7 days following the 2nd heading session
Neurite Orientation Dispersion and Density Imaging (NODDI)	NODDI metrics will be derived from the the diffusion tensor images using the NODDI toolbox v1.0 in Matlab. Maps of neurite density (ND), orientation dispersion (OD), and intracellular volume fraction (ICVF) will be generated.	Baseline, 24 hours following 1st and 2nd heading sessions, 7 days following the 2nd heading session
Resting-state functional connectivity	Resting-state connectivity will be examined throughout the whole brain and specific seeded regions including the dorsolateral prefrontal cortex (DLPFC), angular gyrus, and cingulate gyrus.	Baseline, 24 hours following 1st and 2nd heading sessions, 7 days following the 2nd heading session
Cognition	Cognitive function will be measured using the NIH Toolbox Cognition Battery, which has excellent reliability and validity to measure cognition in young adults, and has construct validity among those with TBI. Multiple forms will minimize learning effects. This battery examines 5 cognitive domains (executive function, episodic memory, language, working memory, and processing speed) and takes 20 minutes to complete on a tablet.	Baseline, 24 hours following 1st and 2nd heading sessions, 7 days following the 2nd heading session
Cerebral Blood Flow	Perfusion imaging will be acquired to examine cerebral blood flow.	Baseline, 24 hours following 1st and 2nd heading sessions, 7 days following the 2nd heading session

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Genetic markers	Several genetic markers that are known to associate with brain vulnerability will be assessed and regressed against our outcome measures. These genetic markers include, but not limited to, DARC, APOE, KIAA0319, BDNF, TPH2, COMT. Each marker will be compared to the other outcome measures to understand the full effect of the intervention on the genetic markers as a whole.	Baseline
ADHD	Participants who meet criteria for ADHD diagnosis will be analyzed to address the interactive effects of DHA+EPA and head impacts in ADHD.	Baseline

Collaborators and Investigators

• Sponsor: Indiana University
• Collaborators: National Institute of Neurological Disorders and Stroke (NINDS)

Publications and helpful links

General Publications

• Shahim P, Zetterberg H, Tegner Y, Blennow K. Serum neurofilament light as a biomarker for mild traumatic brain injury in contact sports. Neurology. 2017 May 9;88(19):1788-1794. doi: 10.1212/WNL.0000000000003912. Epub 2017 Apr 12.
• Marchi N, Bazarian JJ, Puvenna V, Janigro M, Ghosh C, Zhong J, Zhu T, Blackman E, Stewart D, Ellis J, Butler R, Janigro D. Consequences of repeated blood-brain barrier disruption in football players. PLoS One. 2013;8(3):e56805. doi: 10.1371/journal.pone.0056805. Epub 2013 Mar 6.
• Kawata K, Rubin LH, Takahagi M, Lee JH, Sim T, Szwanki V, Bellamy A, Tierney R, Langford D. Subconcussive Impact-Dependent Increase in Plasma S100beta Levels in Collegiate Football Players. J Neurotrauma. 2017 Jul 15;34(14):2254-2260. doi: 10.1089/neu.2016.4786. Epub 2017 Apr 27.
• Puvenna V, Brennan C, Shaw G, Yang C, Marchi N, Bazarian JJ, Merchant-Borna K, Janigro D. Significance of ubiquitin carboxy-terminal hydrolase L1 elevations in athletes after sub-concussive head hits. PLoS One. 2014 May 7;9(5):e96296. doi: 10.1371/journal.pone.0096296. eCollection 2014.
• Oliver JM, Jones MT, Kirk KM, Gable DA, Repshas JT, Johnson TA, Andreasson U, Norgren N, Blennow K, Zetterberg H. Serum Neurofilament Light in American Football Athletes over the Course of a Season. J Neurotrauma. 2016 Oct 1;33(19):1784-1789. doi: 10.1089/neu.2015.4295. Epub 2016 Mar 16.
• Oliver JM, Anzalone AJ, Stone JD, Turner SM, Blueitt D, Garrison JC, Askow AT, Luedke JA, Jagim AR. Fluctuations in blood biomarkers of head trauma in NCAA football athletes over the course of a season. J Neurosurg. 2018 May 29;130(5):1655-1662. doi: 10.3171/2017.12.JNS172035. Print 2019 May 1.
• Joseph JR, Swallow JS, Willsey K, Lapointe AP, Khalatbari S, Korley FK, Oppenlander ME, Park P, Szerlip NJ, Broglio SP. Elevated markers of brain injury as a result of clinically asymptomatic high-acceleration head impacts in high-school football athletes. J Neurosurg. 2018 Jul 3;130(5):1642-1648. doi: 10.3171/2017.12.JNS172386. Print 2019 May 1.
• Tierney GJ, Higgins B. The incidence and mechanism of heading in European professional football players over three seasons. Scand J Med Sci Sports. 2021 Apr;31(4):875-883. doi: 10.1111/sms.13900. Epub 2021 Jan 18.
• Peek K, Vella T, Meyer T, Beaudouin F, McKay M. The incidence and characteristics of purposeful heading in male and female youth football (soccer) within Australia. J Sci Med Sport. 2021 Jun;24(6):603-608. doi: 10.1016/j.jsams.2020.12.010. Epub 2020 Dec 26.
• Russell ER, Mackay DF, Stewart K, MacLean JA, Pell JP, Stewart W. Association of Field Position and Career Length With Risk of Neurodegenerative Disease in Male Former Professional Soccer Players. JAMA Neurol. 2021 Sep 1;78(9):1057-1063. doi: 10.1001/jamaneurol.2021.2403.
• Mackay DF, Russell ER, Stewart K, MacLean JA, Pell JP, Stewart W. Neurodegenerative Disease Mortality among Former Professional Soccer Players. N Engl J Med. 2019 Nov 7;381(19):1801-1808. doi: 10.1056/NEJMoa1908483. Epub 2019 Oct 21.
• Beauregard LH, Bazarian JJ, Johnson BD, Cheng H, Ellis G, Kronenberger W, Calder PC, Chen Z, Silveyra P, Quinn PD, Newman SD, Mickleborough TD, Kawata K. Investigating omega-3 fatty acids' neuroprotective effects in repetitive subconcussive neural injury: Study protocol for a randomized placebo-controlled trial. PLoS One. 2025 Apr 24;20(4):e0321808. doi: 10.1371/journal.pone.0321808. eCollection 2025.

Study record dates

Study Major Dates

• Study Start (Actual): February 28, 2025
• Primary Completion (Estimated): May 31, 2029
• Study Completion (Estimated): May 31, 2029

Study Registration Dates

• First Submitted: October 22, 2024
• First Submitted That Met QC Criteria: December 11, 2024
• First Posted (Actual): December 17, 2024

Study Record Updates

• Last Update Posted (Actual): April 29, 2026
• Last Update Submitted That Met QC Criteria: April 28, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: TBI; Omega-3 fatty acids; Subconcussive brain injury; Soccer heading
• Additional Relevant MeSH Terms: Fatty Acids; Lipids; Fatty Acids, Unsaturated; Oils; Dietary Fats; Fats; Dietary Fats, Unsaturated; Fish Oils; Fatty Acids, Omega-3
• Other Study ID Numbers: 21334; R01NS137276 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No