Higher serum ascorbic acid levels are associated with lower depression prevalence in US adults: a case-control study

Mengyuan Chen; Haolong Luo; Yan Han; Yuanhong Li; Li Zhou; Xiangmei Ren

doi:10.3389/fnut.2024.1324835

Higher serum ascorbic acid levels are associated with lower depression prevalence in US adults: a case-control study

Front Nutr. 2024 Jan 26:11:1324835. doi: 10.3389/fnut.2024.1324835. eCollection 2024.

Authors

Mengyuan Chen^{1

2}, Haolong Luo^{1

2}, Yan Han^{1

2}, Yuanhong Li^{1

2}, Li Zhou^{1

2}, Xiangmei Ren^{1

2}

Affiliations

¹ Department of Nutrition, School of Public Health, Xuzhou Medical University, Xuzhou, China.
² Key Laboratory of Human Genetics and Environmental Medicine, Key Lab of Environment and Health, Xuzhou Medical University, Xuzhou, China.

Abstract

Background: Recent studies have shown that a higher intake of ascorbic acid was associated with a lower prevalence of depression. Nevertheless, the recall bias was common in dietary surveys in these studies, and it was ignored that there were differences in the absorption and utilization of ascorbic acid in the body. Hence, we aim to investigate the association between serum ascorbic acid levels and the prevalence of depression in US adults.

Methods: A total of 3,404 participants from the 2017-2018 National Health and Nutrition Examination Survey (NHANES) that underwent measurement of the Patient Health Questionnaire-9 (PHQ-9) scores and serum levels of ascorbic acid. Propensity Score Matching (PSM) successfully established a case-control study, comprising 299 participants diagnosed with depression and 1,107 as controls. We used binary logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) to explore associated risk factors for depression. Restricted cubic splines (RCS) were used to show the nonlinear relationship between serum ascorbic acid levels and the prevalence of depression.

Results: The prevalence of depression was approximately 8.8%, with a median serum ascorbic acid level of 49.9 (36.0, 67.0) μmol/L. Results revealed that the serum ascorbic acid levels of depressed patients were significantly lower than those of non-depressed individuals (42.97 VS 52.97 μmol/L). The baseline data indicated that as serum ascorbic acid levels increased from Quartile 1 (Q₁) to Quartile 4 (Q₄), the depression prevalence decreased from 12.0 to 5.4% (p < 0.05). The results of the chi-square test after PSM showed that serum ascorbic acid was still statistically significant (p < 0.001) with the prevalence of depression. Forest plot showed that compared with the Q₁ of serum ascorbic acid level, the OR and 95%CI of depression prevalence in Q₄ was 0.42 (0.30 ~ 0.61), and the adjusted OR and 95%CI of depressive prevalence was 0.49 (0.33 ~ 0.73). RCS models showed an L-shaped nonlinear relationship (P for nonlinearity <0.05) between serum ascorbic acid and depression.

Conclusion: Our results suggested that higher serum ascorbic acid levels are associated with a reduced prevalence of depression.

Keywords: NHANES; depression; propensity score matching; restricted cubic spline; serum ascorbic acid.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by the National Natural Science Foundation of China (82204056 and 81302429), the Postgraduate and Undergraduate Research & Practice Innovation Program of Jiangsu Province (KYCX21_2726 and 202010313060Y), and Jiangsu Overseas Visiting Scholar Program for University Prominent Young & Middle-aged Teachers and Presidents.