Antioxidant-rich diet intake reduces risk of hypothyroidism, finds study

A new study published in the journal of BMC Endocrine Disorders found that antioxidants such as zinc, selenium, magnesium, and vitamins C, A, and E were linked to a 56% decreased incidence of hypothyroidism.

One of the key glands in the endocrine system, the thyroid plays a crucial role in homeostasis, growth and development, and healthy reproduction. The clinical spectrum of hypothyroidism, an endocrine disorder characterized by decreased blood thyroxin levels, ranges from no symptoms to severe problems. The pathophysiological process of hypothyroidism involves inflammation and oxidative stress.

Hypothyroidism is a widespread thyroid illness that affects the health of people worldwide. Numerous illnesses have been linked to the comprehensive dietary antioxidant index (CDAI), which measures the total antioxidant capability of the diet. It is unclear, therefore, how CDAI and the risk of hypothyroidism are related. Using data from the National Health and Nutrition Examination Surveys (NHANES), this study investigated the relationship between CDAI and the risk of hypothyroidism. This work was set to offer a theoretical foundation for lowering the burden of thyroid disorders from the standpoint of dietary improvement.

The National Health and Nutrition Examination Surveys (NHANES) database from 2007–2012 provided the data for this investigation. Vitamins C, A, E, magnesium, zinc, and selenium were used to determine CDAI, which stands for the total dietary nutrient capacity. Hypothyroidism was defined as thyroid stimulating hormone (TSH) > 5.6 mIU/L.

The association between CDAI and hypothyroidism was assessed using weighted multivariate logistic regression models and propensity score matching (PSM) analysis, with odds ratios (ORs) and 95% CIs. The association between CDAI and hypothyroidism was further assessed using subgroup and sensitivity analysis. Additionally, the relationship between hypothyroidism and the elements of CDAI was investigated.

There were 7,959 participants in total, including data on thyroid function and total food intake. Of them, hypothyroidism was present in 213 (2.68%) patients. This research found that a high CDAI was associated with a reduced incidence of hypothyroidism after adjusting for all other variables.

This association was more pronounced in male individuals aged <65 years with a BMI of ≥25 kg/m2. Even after excluding those who used thyroid hormones, there was still a strong correlation between high CDAI and low risk for hypothyroidism. Overall, the people in the US who had a high CDAI were also less likely to have hypothyroidism. To uncover their link, further extensive prospective research is still required.

Reference:

Chang, J., Wang, N., Cheng, Y., & Chen, X. (2025). Relationship of comprehensive dietary antioxidant index and hypothyroidism risk: evidence from the National Health and Nutrition Examination Surveys 2007–2012. BMC Endocrine Disorders, 25(1). https://doi.org/10.1186/s12902-024-01806-y