COVID-19, which is caused by SARS-CoV-2, is characterized by various symptoms, ranging from mild fatigue to life-threatening pneumonia, “cytokine storm,” and multiorgan failure. The manifestation of COVID-19 may lead to a cytokine storm, i.e., it facilitates viral replication that triggers a strong release of cytokines, which then modulates the immune system and results in hyperinflammation. Today’s diet is high in omega-6 fatty acids and deficient in omega-3 fatty acids; this, along with a high fructose intake, leads to obesity, which is a chronic state of low-grade inflammation. Omega-6 fatty acids are proinflammatory and prothrombotic whereas omega-3 fatty acids are less proinflammatory and thrombotic. Furthermore, omega-3 fatty acids make specialized lipid mediators, namely resolvins, protectins, and maresins, that are potent anti-inflammatory agents. Throughout evolution there was a balance between omega-6 and omega-3 fatty acids with a ratio of 1–2/1 omega-6/omega-3, but today this ratio is 16–20/1 omega-6/omega-3, leading to a proinflammatory state. In addition, genetic variants in FADS1, FADS2, ELOV-2, and ELOV-5 lead to a more efficient biosynthesis of long-chain polyunsaturated fatty acids (PUFAs), e.g., of linoleic acid (LA) to arachidonic acid (ARA), and (alpha-linolenic acid) (ALA) to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), leading to higher ARA levels. Because the US diet is already high in omega-6 fatty acids, the increased biosynthesis of ARA in people with the derived FADS haplotype (haplotype D) leads to an increased production of leukotrienes, thromboxanes, C-reactive protein (CRP), and eventually elevated levels of cytokines, like interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF), which may increase susceptibility to COVID-19. About 80% of African Americans, 50% of Hispanics, and 45% of European Americans have the FADS haplotype D and are thus efficient metabolizers, which could account for the higher vulnerability of these populations to COVID-19. Therefore, another reason that African Americans and Hispanics are more susceptible to COVID-19 is that they have a higher frequency of haplotype D, which is no longer beneficial in today’s environment and diet. Genetic variation must be considered in all studies of disease development and therapy because it is important to the practice of precision nutrition by physicians and other health professionals. The objective of this commentary is to emphasize the importance of genetic variation within populations and its interaction with diet in the development of disease. Differences in the frequency of genes and their interactions with nutrients in various population groups must be considered among the factors contributing to health disparities in the development of COVID-19. A balanced omega-6/omega-3 ratio is essential to health. Physicians should measure their patients’ fatty acids and recommend decreasing the intake of foods rich in omega-6 fatty acids and increasing the intake of omega-3 fatty acids along with fruits and vegetables.
Lifestyle Genomics

中文翻译：

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遗传变异，饮食，炎症和COVID-19的风险

由SARS-CoV-2引起的COVID-19具有多种症状，从轻度疲劳到威胁生命的肺炎，“细胞因子风暴”和多器官衰竭。COVID-19的表现可能导致细胞因子风暴，即它促进病毒复制，从而触发细胞因子的强烈释放，进而调节免疫系统并导致过度炎症。当今的饮食中，omega-6脂肪酸含量很高，而omega-3脂肪酸含量却不足。这与高果糖摄入一起导致肥胖，这是低度炎症的慢性状态。Omega-6脂肪酸促炎和血栓形成，而Omega-3脂肪酸促炎和血栓形成较少。此外，omega-3脂肪酸可形成专门的脂质介体，即RESOLVIN，保护素和Maresins，是有效的抗炎药。在整个进化过程中，omega-6和omega-3脂肪酸之间的平衡为1–2 / 1 omega-6 / omega-3，但今天该比例为16–20 / 1 omega-6 / omega-3 ，导致促炎状态。此外，FADS1，FADS2，ELOV-2和ELOV-5中的遗传变异导致长链多不饱和脂肪酸（PUFA）（例如亚油酸（LA）到花生四烯酸（ARA））的生物合成更有效， （α-亚麻酸）（ALA）变为二十碳五烯酸（EPA）和二十二碳六烯酸（DHA），导致较高的ARA水平。由于美国的饮食中已经含有丰富的omega-6脂肪酸，因此具有衍生FADS单体型（单体型D）的人ARA的生物合成增加，导致白三烯，血栓烷，C反应蛋白（CRP）的产生增加，并最终导致白细胞介素（IL）-1，IL-6和肿瘤坏死因子（TNF）等细胞因子水平升高，这可能会增加对COVID-19的敏感性。大约80％的非洲裔美国人，50％的西班牙裔美国人和45％的美国人具有FADS单倍型D，因此是有效的代谢者，这可能是这些人群更容易感染COVID-19的原因。因此，非洲裔美国人和西班牙裔人更容易感染COVID-19的另一个原因是，他们的单倍型D发生频率更高，这对当今的环境和饮食不再有益。在疾病发展和治疗的所有研究中都必须考虑遗传变异，因为遗传变异对于医生和其他卫生专业人员实施精确营养非常重要。本评论的目的是强调人群中遗传变异及其在疾病发展中与饮食的相互作用的重要性。在导致COVID-19发育中健康差异的因素中，必须考虑基因频率的差异以及它们与不同人群的养分相互作用的差异。平衡的omega-6 / omega-3比例对健康至关重要。医生应测量患者的脂肪酸，并建议减少富含omega-6脂肪酸的食物的摄入量，并增加omega-3脂肪酸以及水果和蔬菜的摄入量。在导致COVID-19发育中健康差异的因素中，必须考虑基因频率的差异以及它们与不同人群的养分相互作用的差异。平衡的omega-6 / omega-3比例对健康至关重要。医生应测量患者的脂肪酸，并建议减少富含omega-6脂肪酸的食物的摄入量，并增加omega-3脂肪酸以及水果和蔬菜的摄入量。在导致COVID-19发育中健康差异的因素中，必须考虑基因频率的差异以及它们与不同人群的养分相互作用的差异。平衡的omega-6 / omega-3比例对健康至关重要。医生应测量患者的脂肪酸，并建议减少富含omega-6脂肪酸的食物的摄入量，并增加omega-3脂肪酸以及水果和蔬菜的摄入量。
生活方式基因组学