The relationship between dietary total flavonoids and thyroid function in U.S.adults, NHANES 2007–2010

• Published in: PloS one Vol. 19; no. 5; p. e0303169
• Main Authors: Wu, Jie, Jia, Chuyu, Zhang, Zirui, Hou, Zebin, Cui, Yanhua
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 21.05.2024; Public Library of Science (PLoS)
• Subjects: Adult; Adults; Age; Alcohol; Analysis; Biology and Life Sciences; Body mass index; Diet; Dietary intake; Education; Epidemiology; Ethnicity; Family income; Female; Flavonoids; Flavonoids - administration & dosage; Health surveys; Humans; Income; Isoflavones; Male; Medical research; Medicine and Health Sciences; Medicine, Experimental; Middle Aged; Nutrition Surveys; Poverty; Secondary schools; Smoking; Social Sciences; Spline functions; Subgroups; Surveys; Thyroid; Thyroid diseases; Thyroid Function Tests; Thyroid gland; Thyroid Gland - metabolism; Thyroid Gland - physiology; Thyroid hormones; Thyroxine; Thyroxine - blood; Triiodothyronine; United States; Variables; Variance analysis; United States; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0303169

Although small studies have shown that flavonoids can affect thyroid disease, few epidemiological studies have explored the relationship between dietary total flavonoids (TFs) intake and serum thyroid function. The aim of this research was to evaluate the relationship between TFs and serum thyroid function. Our study included 4,949 adults from the National Health and Nutrition Examination Survey (NHANES) 2007-2010. Multivariable linear regression, subgroup analyses, and interaction terms were used to explore the relationships between TFs and thyroid function. And we also used restricted cubic splines (RCS) to investigate possible nonlinear relationships. After adjusting for covariates, we found that log10-transformated dietary total flavonoids intake (LgTFs) was negatively associated with total thyroxine (TT4) (β = -0.153, 95% CI = -0.222 to -0.084, P<0.001). Subgroup analyses revealed a stronger and statistically supported association in subjects with high annual family income (β = -0.367, P<0.001, P for interaction = 0.026) and subjects with high poverty to income ratio (PIR) (β = -0.622, P<0.001, P for interaction = 0.042). And we found a U-shaped curve association between LgTFs and free triiodothyronine (FT3) (inflection point for LgTFs: 2.063). The results of our study demonstrated that a higher intake of total flavonoids in the diet was negatively associated with a lower TT4. Furthermore, the associations were more pronounced in high annual family income and high PIR adults. And we found a U-shaped relationship between LgTFs and FT3. These findings provided guidance for future thyroid dysfunction diet guidelines.