Association Between Soy Product Intake and Insomnia in Chinese Middle-Aged and Older Adults: A Cross-Sectional Study

Insomnia has various adverse effects on middle-aged and older adults. Improving insomnia by adjusting diet has attracted attention. This study investigated the relationship between soy product intake and insomnia in middle-aged and older adults and explored the role of inflammatory factors.

The study included 877 middle-aged and older adults aged ≥45 years which from general patients who made an appointment or were admitted to the cardiology department at Wenling Hospital in Taizhou City. The proportion of female participants is 35.01%. Soy product intake was assessed using the Food Frequency Questionnaire (FFQ), sleep was quantified using the Insomnia Severity Index (ISI). The median (IQR) of soy product intake is ≤1 time per week (≤1 time per week, 2-6 times per week) and the mean/SD value of insomnia score is 5.43/5.13.

In Chinese middle-aged and older adults, soy product intake was negatively correlated with insomnia (|r|s ≥ 0.117, ps < 0.001), C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α) and triglyceride (TG) levels (adjusted β: -0.139, 95% CI: -0.265 to -0.012; β: -0.049, 95% CI: -0.091 to -0.006; β: -0.043, 95% CI: -0.085 to -0, respectively). There was no significant correlation between soy product intake and White Blood Cell (WBC), Absolute Neutrophil Count (GRAM), Platelet Count (PLT), Interleukin-1β (IL-1β), Interleukin-2 (IL-2), Interleukin-6 (IL-6), Hemoglobin (Hb), Red Blood Cell (RBC), Low-Density Lipoprotein Cholesterol (LDL-C), High-Density Lipoprotein Cholesterol (HDL-C) and Total Cholesterol (TC) levels.

Lower levels of soy product intake are associated with higher rates of insomnia in the middle-aged and older adults. Additionally, soy product intake is negatively correlated with peripheral blood CRP, TNF-α and TG levels. This study provides a new clinical perspective for middle-aged and older adults to enhance sleep through a balanced diet, wherein the inflammation and lipid may play a potentially crucial role.