Association between dietary flavonoid intake and anxiety: data from NHANES 2017-2018

Anxiety disorders are among the most prevalent mental health conditions, characterized by excessive fear, tension, avoidance behaviors, and heightened threat perception. Approximately 1 in 14 individuals meets the diagnostic criteria for an anxiety disorder. Flavonoids, bioactive compounds found in fruits, vegetables, and tea, possess antioxidant, anti-inflammatory, and neuroprotective properties. However, evidence on the relationship between flavonoid intake and anxiety risk remains limited. This study examines the association between flavonoid intake and anxiety risk and explores the effects of specific flavonoid subclasses.

This study utilized data from the National Health and Nutrition Examination Survey (NHANES). Individual flavonoid intake was assessed using two-day 24-hour dietary recalls, and anxiety status was evaluated through a standardized anxiety questionnaire. To assess the relationship between flavonoid intake and anxiety risk, weighted logistic regression analysis was performed. Additionally, restricted cubic spline (RCS) analysis was employed to evaluate potential nonlinear associations. We conducted subgroup analyses for flavonoids that showed significant associations in the logistic regression, including theaflavin-3-gallate, total flavones, total flavanones, total isoflavones, and naringenin. These analyses aimed to explore the moderating effects of demographic characteristics such as sex, age, marital status, smoking status, and body mass index (BMI).

We analyzed data from 1,637 participants in the NHANES. Significant differences were observed between the anxious and non-anxious groups in age, poverty-income ratio (PIR), BMI, smoking status, marital status, education level, and flavonoid intake. The anxious group had higher age (47.12 vs. 42.81 years, P < 0.0001), PIR (P < 0.0001), and BMI (P = 0.01). They also had a higher proportion of females, unmarried individuals, and current smokers (P < 0.0001). Logistic regression analysis showed that genistein, petunidin, naringenin, apigenin, and total flavones were significantly associated with reduced anxiety risk (P < 0.05). Subgroup analysis confirmed protective effects in males, married individuals, participants with General Educational Development (GED)-level education, and specific ethnic groups. RCS analysis suggested nonlinear relationships, with total flavones, total flavanones, and naringenin showing protective effects at low intake levels (P < 0.05). All models demonstrated good fit (P < 0.001).

Flavonoid intake is inversely associated with anxiety risk, particularly Theaflavin-3-gallate, Total Flavones, Total Flavanones, Total Isoflavones, and Naringenin. Further studies are needed to confirm optimal intake levels and underlying mechanisms.