Page 48 - JSOM Summer 2024

omega-3 dosage, number of traumatic brain injuries, O3I, but had a negative association to risk status (Table 3), meaning
O6:O3 ratio, and number of deployments and the following the more fish/omega 3 someone consumed, the lower their risk
categorical variables: incidence of brain fog, headache, expo- category.
sure to door breaching, overpressures (increase in air pressure
due to close proximity to weapon blast), being a shooting Cluster Analysis
instructor, and playing contact sports, as well as exposure to Three clusters were formed (Table 4). Cluster 1 was generally
friendly (experienced during training) and enemy (experienced described as a highly exposed cluster, characterized by more
during combat) explosions. Cluster analysis is a family of cases, who were breachers and shooting instructors, had more
non-hypothesis-driven procedures used to consolidate similar deployments, were exposed to more overpressures and ex-
groups of cases from a large cohort using a group of pertinent plosions, and reported more TBIs, brain fog, and headaches.
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variables. Two-step cluster analysis is a special type of cluster This cluster also reported a higher median fish consumption
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analysis that considers categorical and continuous variables. than cluster 3 and approximately as much as cluster 2. They
A total of 213 cases had complete data for the fields chosen in also appeared to have a higher mean consumption of omega-3
this analysis. The average silhouette measure of cohesion and supplementation (Figure 1). However, cluster 1 had a slightly
separation was 0.3, indicating a fair fit. lower O3I than the other two clusters and a slightly higher
O6:O3 ratio than cluster 2.
Results
FIGURE 1 Omega-3 index risk category and omega-3 supplement
Survey data were available for 351 participants (10 partici- intake.
pants did not answer 1–3 questions). O3FA status was avail-
able for 329 participants. All participants were included in the Estimated Marginal Means of the Omega 3 Index
analyses, and missing data is indicated by an n<351. Table 1 12.00 Omega 3
presents participants’ self-reported descriptive characteristics. Supplement
use
10.00 * no yes
Omega-3 Status 8.00
O3I, O6:O3 ratio, and Omega Score Estimated Marginal Means 6.00 *
Omega-3 status indices, including O3I scores and risk status, 4.00 *
O6:03 ratio, and Omega Score are presented in Table 2. The 2.00
O6:O3 ratio was inversely correlated with O3I (r=–0.788,
p<.001). The r-values (measure of association) and p-values are 0 high risk moderate risk low risk
included for transparency of statistical reporting for scientists
Omega 3 Index Category
wishing to replicate this work. A correlation (r=0.911, p<.001) Non-estimate means are not plotted
was observed between Omega Score and O3I, indicating that Error bars: 95% CI
Omega Score and O3I measured the same factors. Therefore,
Omega Score was not investigated further, as any significant *2-way ANOVA, p<.001. Supplemented groups were significantly
different from non-supplemented groups. Each risk category was
findings with O3I would be expected to be the same as those significantly different (p<.001) from the others. There was a signif-
of the Omega Score. O3I is also more commonly reported in icant interaction (p=.016) between the risk categories and omega-3
the literature and has accepted categorical boundaries. supplementation.

TABLE 2 Omega-3 Status Indices (n=329) Cluster 2 was generally described as a moderately exposed
Mean (SD)* cluster. This group reported exposure to overpressures, friendly
O3I status explosions, and collision sports, but were less inclined to be
O3I 4.2 (1.3) shooting instructors or breachers. They generally reported less
O6:O3 ratio 8.0 (1.8) exposure to enemy explosions and reported fewer headaches.
They also reported no brain fog. This cluster had the lowest
Omega Score 5.1 (1.2) O6:O3 ratio and had the highest O3I. They reported eating
O3I risk status, no. (%) approximately as much fish as cluster 1.
High risk (<4%) 166 (50.5)
Moderate risk (4–8%) 158 (48.0) Cluster 3 was generally described as a low exposure cluster.
Low risk (>8) 5 (1.5) They reported the lowest number of deployments and TBIs, no
*Unless otherwise specified. explosions, and fewer symptoms, and they were least inclined
to be breachers. There was no shooting instructor in this clus-
Impact of Fish Consumption and O3FA Supplements ter. Their O6:O3 ratios were approximately the same as those
Fish servings per week were positively correlated to O3I of cluster 1, and also this cluster had the lowest consumption
(r=0.219, p<.001) and negatively correlated to O6:O3 ratio of fish per week. All three clusters reported substantial partic-
(r=–0.245, p<.001). All participants (n=5) in the low-risk O3I ipation in collision sports.
category reported taking O3FA supplements, while only one
reported consuming fish. Overall, O3FA supplementation had Overpressures had the highest importance in explaining clus-
a more significant impact on omega-3 status compared with ter membership (p<.001, V=1), followed, respectively, by brain
fish consumption (Table 3). fog, deployments, headache, being a breacher, friendly and
enemy explosions, being a shooting instructor, TBI, omega-3
O3FA supplementation (yes/no) and fish consumption (ordi- supplementation, contact sport, O6:O3 ratio, weekly servings
nal) were significantly and positively related to O3I quintiles of fish, and O3I. All variables, but omega-3 supplementation,

46 | JSOM Volume 24, Edition 2 / Summer 2024