This study utilized data from the 2023 KNHANES to examine the association between GAD and oral functional impairments, specifically difficulties in chewing and speaking, among Korean postmenopausal women. Furthermore, the research investigated the mediating role of health literacy in this relationship. The analysis revealed that individuals with GAD experienced significantly greater chewing difficulties compared to those without GAD. Additionally, GAD was found to significantly reduce health literacy, which in turn had a notable indirect effect in worsening both chewing and speaking impairments, thereby providing statistical evidence for the mediating role of health literacy. These findings align with previous studies linking mental health disorders to oral health outcomes [6,8,9], and this study uniquely contributes by empirically validating this association within the specific population of postmenopausal women.

Postmenopausal women represent a demographic characterized by heightened susceptibility to both GAD and oral functional impairments, attributable to a combination of biological and psychosocial factors. The reduction in estrogen levels during menopause is linked to decreased salivary secretion, mucosal atrophy, xerostomia, and increased vulnerability of periodontal tissues, collectively exacerbating oral functional decline [2]. Psychological stressors, including anxiety, further activate the sympathetic nervous system and contribute to harmful oral behaviors such as bruxism and temporomandibular joint strain, which may intensify pain and impair masticatory performance [3,4,9,11]. Additionally, postmenopausal women often experience concomitant conditions such as alveolar bone resorption, reduced bone mineral density, and age-related deterioration of masticatory function, rendering them more functionally vulnerable compared to other demographic groups defined by age and gender. Unlike previous studies that primarily focused on young adults or the general adult population, the present study is distinguished by its emphasis on postmenopausal women, a cohort undergoing intersecting physiological and psychological changes. A key finding of this study is the significant mediating role of health literacy in the relationship between GAD and oral functional impairments. Health literacy involves not only the acquisition of health-related information but also the ability to comprehend, critically evaluate, and apply such information to promote effective health behaviors [13]. Individuals with elevated anxiety levels frequently experience deficits in attention, cognitive processing, and problem-solving skills, which hinder their ability to assimilate complex health information and implement appropriate behavioral strategies. The results of this study suggest an indirect pathway whereby reduced health literacy impairs the adoption of oral health management practices, ultimately leading to functional decline. Empirical evidence supports that populations with low health literacy are less likely to engage in preventive oral health behaviors—such as interdental cleaning, use of oral rinses, and fluoride application—and are more likely to delay dental consultations when early symptoms arise [14]. These findings highlight that improving health literacy extends beyond increasing knowledge; it represents a crucial mediating mechanism for restoring self-efficacy diminished by anxiety and promoting preventive oral health behaviors.

Although the indirect effects identified in this study (0.002 for chewing function impairments and 0.001 for speaking function impairments) are statistically significant, the absolute effect sizes are relatively small. However, these findings should be understood not as substantial changes at the individual level but as clinically and practically meaningful indicators at the population level. This implies that even slight enhancements in health literacy among postmenopausal women with GAD may reduce the cumulative risk of oral functional decline within this population.

Among postmenopausal women—who face an elevated risk of progressive tooth loss, denture dependency, masticatory dysfunction, and subsequent social withdrawal—the early identification of high-risk subpopulations characterized by coexisting mental health conditions, such as GAD, and limited health literacy is essential. The implementation of targeted educational interventions, counseling, and comprehensive oral health management for these groups may constitute a clinically significant preventive strategy.

Oral functional decline encompasses more than simple discomfort; it significantly impairs the oral health-related quality of life (OHRQoL) in postmenopausal women. Previous studies have established that functional oral health problems, such as difficulties with mastication and speech, are closely associated with diminished OHRQoL due to challenges in eating, articulation, and social interaction [19–21]. Importantly, in elderly and vulnerable populations, masticatory impairments have been correlated with limited nutritional intake and declining overall health, whereas speech difficulties may lead to social isolation and psychological withdrawal.

The pathway elucidated in this study—where GAD influences health literacy, subsequently impacting oral functional impairments—carries important clinical implications. This sequence indicates not only an immediate decline in oral function but also a heightened risk of progressive deterioration in OHRQoL over the medium to long term.

These results carry substantial implications for both clinical practice and public health initiatives. Primarily, oral health care for postmenopausal women should not be limited to routine dental examinations and educational activities; rather, it should encompass systematic screening for anxiety and the provision of individualized interventions. The integration of brief screening instruments, such as the GAD 7-item scale, within primary care and dental environments can effectively identify individuals at heightened risk for GAD. Following identification, appropriate referrals to mental health services or the establishment of multidisciplinary collaboration frameworks involving dental, mental health, and women’s health specialists are both practicable and beneficial from a clinical perspective. Furthermore, efforts to improve health literacy must go beyond the simple transmission of information and actively promote the conversion of knowledge into practical health behaviors. This objective may be accomplished through cognitive-behavioral strategies, including the use of clear, accessible language tailored to the patient’s level of understanding, the incorporation of visual supports, experiential learning methods, and structured behavioral planning [13–15].

Specifically, for individuals presenting with heightened anxiety, tailored educational approaches that address the quality of information, modes of delivery, and practical relevance are essential. This suggests that improving health literacy could serve as a viable intervention to reduce indirect functional deterioration linked to anxiety. In particular, for postmenopausal women who may experience an increased cognitive load as a result of elevated anxiety, it is clinically important to provide oral health education through succinct and focused messaging, repeated instructional sessions, and the engagement of family members.

Thirdly, the implementation of programs that combine mental health education with oral health education targeting high-risk populations—specifically individuals with GAD or socioeconomically vulnerable postmenopausal women—within communitybased interventions, such as those delivered at public health centers and local dental health facilities, is highly feasible. Such integrated approaches have the potential to promote more favorable dental care utilization patterns and to enhance OHRQoL in the long term.

This study is significant in that it empirically elucidates the mediating mechanisms linking GAD, health literacy, and oral health functional impairments among postmenopausal women, drawing upon large-scale data representative of the national population. Nonetheless, given its cross-sectional design, the study precludes causal interpretations. Furthermore, the exclusive use of selfreported measures for both health literacy and oral functional difficulties raises concerns regarding potential response bias. Importantly, unlike knowledge-based health literacy items that assess accuracy of responses, none of the ten self-reported items exhibited significant differences between GAD groups, suggesting that these measures should be applied with caution. Moreover, although the health literacy metric employed in the KNHANES [15] offers a broad overview, it lacks the granularity necessary for in-depth analysis of specific dimensions such as comprehension, evaluation, and application. Furthermore, the relatively modest absolute magnitude of the indirect effect identified in this study suggests the existence of a mediating effect; nevertheless, it also indicates that the immediate clinical implications may be limited. This constraint should be taken into careful consideration when interpreting the results. Future investigations are encouraged to utilize oral health issues as mediating variables to facilitate comparative analyses. Moreover, the application of hierarchical regression analysis is recommended to more accurately quantify the extent of the mediating effect. Longitudinal research designs are also essential to clarify the temporal and causal relationships among GAD, health literacy, and oral functional impairments. Lastly, intervention studies evaluating the efficacy of programs aimed at improving health literacy in relation to actual functional outcomes and OHRQoL are warranted.