A dietary intervention may improve tiredness in children with subclinical hypothyroidism (SCH), according to the results of a study published in the International Journal of Environmental Research and Public Health.
Dietary supplementation of specific nutrients has not been shown to alter thyroid function or improve clinical symptoms, but the effects of a broader dietary intervention on SCH symptoms has not yet been determined. To investigate whether a diet of unprocessed foods rich in a variety of nutrients improves thyroid functioning and tiredness in SCH, 61 children were enrolled in a randomized controlled trial.
Diagnosis of SCH (thyrotropin [TSH] level >4.2 mU/L and free thyroxine [FT4] within the normal range) was confirmed by a pediatrician. Individuals with clinical hypothyroidism (FT4 <10 pmol/L) or immunologic abnormalities and those who were undergoing treatment with thyroid hormone were excluded.
At baseline, 3 months, and 6 months, participants’ thyroid hormones were measured and their parents completed Pediatric Quality of Life multidimensional fatigue scale questionnaires. In total, 29 children (mean age, 7.7±3.1 years) were randomly assigned to the intervention group and 32 (mean age, 8.1±3.3 years) were randomly assigned to the control group.
The intervention group received dietary advice on the appropriate proportions of foods with the highest concentration of the most important nutrients for thyroid functioning, such as iron, selenium, vitamin A, and iodine. This was accomplished through dietary advice recommending beef 3 times per week, green vegetables 5 times per week, and daily consumption of full-fat milk and butter. Participants were asked to maintain all other dietary habits. A diary was provided to all parents to record adherence to this dietary advice in the intervention group or the daily dietary patterns of the control group.
Overall adherence to the dietary advice was 88.5% in the intervention group and 40% in the control group (P <.001). Both groups met approximately 80% of the green vegetable adherence, and adherence to the advice for the remaining components was >90% for the intervention group. After 6 months, no significant differences were seen in TSH or FT4 levels or thyroid peroxidase antibody positivity between the 2 groups or from baseline in either group. One individual in the control group, however, did have TSH levels that rose above 12 mU/L, and therefore met the criteria for thyroxine supplementation.
After 6 months, the intervention group had significantly improved overall fatigue (P =.04) and sleep scores (P =.03) on the Pediatric Quality of Life fatigue scale compared with the control group, even though the control group’s baseline fatigue scores were slightly higher than the intervention group. No correlation between fatigue scores and TSH levels was established, and no significant differences in growth parameters or changes in lipid profiles were observed between the 2 groups.
Although TSH levels did not change significantly in either group during this study, children in the dietary intervention group had significantly improved general fatigue and sleep scores after 6 months, indicating that the effect of the dietary intervention worked independently from thyroid functioning.
Future research should investigate whether dietary intervention affects other risk markers in SCH, such as dimethylarginine and intima thickness.
van der Gaag E, van der Palen J, Schapp P, van Voorthuizen M, Hummel T. A lifestyle (dietary) intervention reduces tiredness in children with subclinical hypothyroidism, a randomized clinical trial. Int J Environ Res Public Health. 2020;17(10):3689.