Progress on the protective effects of maternal fatty acid supplementation on infant asthma risk: a narrative review.

Asthma is a heterogeneous disease characterized by chronic airway inflammation, and involves a variety of cells and cellular components, which genetic and environmental factors play an important role in the pathogenesis of asthma. It usually occurs in infancy, and epidemiological studies have shown that maternal nutrition during pregnancy is related to the occurrence of asthma in childhood. Fatty acids (FA) are carboxylic acids with different amounts of carbons. Based on the differences between saturated and unsaturated hydrocarbon chains, it can be divided into three categories: saturated fatty acid (SFA, no double bonds between them), monounsaturated fatty acid (MUFA, one double bond), and polyunsaturated fatty acid (PUFA, multiple double bonds). Excessive intake of SFA is the main cause of elevated blood cholesterol, triglyceride, and low-density lipoprotein cholesterol (LDL-C), which leads to arterial lumen stenosis and atherosclerosis, and increases the risk of coronary heart disease. MUFA has hypoglycemic, lipid-lowering, cholesterol-lowering, and antithrombotic effects. SFAs and MUFAs can increase airway inflammation and promote the development of asthma. However, the correlation between maternal SFA and MUFA intake and infant asthma risk has not been reported. The most widely studied PUFA are N-3 PUFA and N-6 PUFA, which mainly derived from vegetable oil, fish oil, and microorganism. As an important component of membrane phospholipids, PUFA can play an immunomodulatory role by affecting the production of eicosanoids, cell membrane fluidity, and gene expression. Maternal intake of PUFAs, especially N-3 PUFAs during pregnancy, can reduce the risk of infant asthma by regulating Th1/Th2 cytokines and immune responses, but a few studies are still controversial. Therefore, large-scale multicenter randomized controlled clinical trials are still warranted to further verify the efficacy of N-3 PUFAs on asthma.