Association between dietary zinc intake and herpes simplex virus seropositivity in US adults: A cross-sectional study

Background: Zinc is an essential trace element crucial for immune function maintenance. However, the relationship between dietary zinc intake and herpes simplex virus (HSV) infection has not been elucidated. This study determined the association between dietary zinc intake and HSV seropositivity, providing new insights into HSV prevention and treatment. Methods: This cross-sectional observational study used data from the United States National Health and Nutrition Examination Survey, conducted between 2007 and 2016. This study cohort comprised adults who provided comprehensive 24-h dietary recall data. Multivariate logistic regression, stratified analysis with interaction, restricted cubic splines (RCS), and threshold effect analyses were used to explore the potential association between dietary zinc intake and HSV seropositivity. Results: In total, 10,689 participants aged 20–49 years were enrolled. Of which, 9,290 (69.9%) were positive for HSV serology (HSV group, including HSV-1 and HSV-2 infections), with 55.5% being female and an average age of 35.9 years. In the fully adjusted model, a significant inverse association was observed between dietary zinc intake and HSV seropositivity (quartile variable, Q4 vs Q1, Odd’s ratio: 0.80, 95% confidence intervals: [0.7–0.91], p = 0.003). Consequently, the association between dietary zinc intake and HSV seropositivity exhibited an L-shaped curve (p <0.001) in the RCS，with an estimated threshold of 16.87 mg/day. Conclusion: This study suggests that a higher intake of dietary zinc may be linked to a lower prevalence of HSV seropositivity. Notably, among adults in the US, an L-shaped relationship was observed between dietary zinc intake and HSV seropositivity, with an estimated threshold of 16.87mg/day.