Introduction: Long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), primarily eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have received considerable interest from the scientific community as a dietary strategy to enhance physical performance, recovery, and neuroprotection in addition to the well-established role of supporting cardiovascular health. Given that military personnel are routinely subjected to psychologically and physiologically (e.g., cardiovascular, musculoskeletal) stressful environments, LC n-3 PUFA intake may represent a simple, yet meaningful, nutritional intervention to support Warfighter health and fitness. Dietary EPA + DHA, via fish or supplement, can be reliably tracked using the omega-3 index (O3i), which is the relative amount of EPA + DHA in red blood cells (RBC) expressed as a percentage of total fatty acids. The purpose of this systematic review was to establish a baseline O3i status in active duty military personnel with the intent of providing actionable evidence-based nutrition recommendations.

Materials and methods: Three databases (PubMed, Google Scholar, and the Omega-3 Clinical Study Database) were searched systematically. A total of 645 articles were screened, of which 11 studies (13 observations) were eligible for inclusion. Non-RBC EPA + DHA (e.g., plasma) was converted to the O3i via validated equations. Data were reported as pooled mean O3i and analyzed based on service type (e.g., Army, Air Force).

Results: Based on 11 studies (13 total observations) composed of 3,615 military personnel, the average O3i was 3.18% (95% CI: 3.15, 3.21) and ranged from 2.47% and 4.62%. Most observations reported an average O3i <4% (76.9%). The Army (combined), U.S. Army only, and Special Forces personnel had O3i <4%, whereas Austrian Army and Air Force personnel had an O3i between 4% and 5%.

Conclusions: Military personnel, without exception, exhibit suboptimal O3i. Achieving optimal O3i is a low cost, modifiable risk factor that can be used in conjunction with traditional medicine and appropriate training to support the military mission and the health and performance of military personnel. Given what we know about LC n-3 PUFAs and the present suboptimal O3i in military personnel, it is paramount that Defense organizations acknowledge the supporting evidence and implement policies and strategies to promote change.

Clinical trial registration: None, but systematic review registration (PROSPERO): CRD42023410361.

Published by Oxford University Press on behalf of the Association of Military Surgeons of the United States 2025. This work is written by (a) US Government employee(s) and is in the public domain in the US.

简介： 长链n-3多不饱和脂肪酸（LC n-3 PUFA），主要包括二十碳五烯酸（EPA）和二十二碳六烯酸（DHA），因其在增强身体表现、恢复及神经保护方面的潜在作用，以及对心血管健康的已知支持作用，在科学界引起了极大的兴趣。鉴于军事人员经常处于心理和生理（如心血管、肌肉骨骼）压力环境中，LC n-3 PUFA的摄入可能代表了一种简单而有意义的营养干预措施，以支持军人健康和体能。通过鱼或补充剂摄取的膳食EPA + DHA可以通过Omega-3指数（O3i）可靠地追踪，它是红细胞（RBC）中EPA + DHA占总脂肪酸百分比的相对量。这项系统综述旨在建立现役军事人员的基础O3i状态，并提供基于证据的营养建议。

材料和方法： 系统性地搜索了三个数据库（PubMed、Google Scholar 和 Omega-3 临床研究数据库）。总共筛选了645篇文章，其中11项研究（共13次观察）符合条件并被纳入。通过验证的方程式将非红细胞EPA + DHA（例如血浆）转换为O3i。数据以合并平均O3i的形式报告，并根据服务类型（如陆军、空军）进行分析。

结果： 基于11项研究（共13次观察，包括3,615名军事人员），平均O3i为3.18%（95% CI：3.15至3.21），范围从2.47%到4.62%。大多数观察报告的平均O3i小于4%（占76.9%）。陆军（合计）、美国陆军单独以及特种部队人员的O3i均低于4%，而奥地利陆军和空军人员的O3i在4%至5%之间。

结论： 所有军事人员，无一例外，都表现出次优水平的O3i。达到最佳O3i是一个低成本、可调整的风险因素，可以在传统医学和适当训练的基础上使用，以支持军事任务以及军人健康与表现。鉴于我们对LC n-3 PUFA的了解以及目前军事人员中次优的O3i状况，国防组织必须承认支持证据并实施政策和策略来促进改变。

临床试验注册： 无，但系统综述已在PROSPERO 注册：CRD42023410361.

由牛津大学出版社代表美国军事外科医生协会于2025年出版。此作品由（a）美国政府雇员编写，且在美国公共领域。