The Impact of Mediterranean Diet on Patients with Hashimoto Thyroiditis

Abstract Background Hashimoto's thyroiditis is one of the most common autoimmune disorders. Patients typically present with nonspecific symptoms, such as fatigue, weight gain, cold intolerance, constipation, and dry skin, which can significantly impair patients' quality of life. Conventional treatments focus on hormone replacement therapy for hypothyroidism, but emerging research suggests dietary interventions, like the Mediterranean diet, may provide added benefits. Many patients continue to suffer from difficulty losing weight despite reaching an euthyroid state while on Levothyroxine. The Mediterranean diet emphasizes fruits, vegetables, whole grains, legumes, nuts, olive oil, fish, poultry, and dairy in moderation. The diet has been known for promoting cardiovascular health and reducing inflammation. Aim Our aim was to explore the Mediterranean diet's impact on Hashimoto's disease and how it affects thyroid autoantibodies and thyroid profile parameters. Methods A single arm clinical trial was performed on 40 female patients diagnosed with Hashimoto’s thyroiditis. Our study participants were started on a modified mediterranean dietary plan for 12 weeks. Evaluation of TSH, free T3, free T4, thyroid peroxidase autoantibodies, thyroglobulin autoantibodies, and BMI was done at baseline and at the end of the study. All of our study participants were kept on their pre-intervention Levothyroxine doses throughout the study. Results We achieved statistically significant reductions in autoantibodies levels, with median % change of (−28.36% (−45.75– −19.05)) for thyroid peroxidase autoantibodies and (−26.09% (−42.76– −14.15)) for thyroglobulin autoantibodies (P < 0.01). Regarding thyroid function tests, statistically significant changes were seen in TSH (−24.95% (−39.6– 18.51)), free T3 (28.4% (9.38 – 66.79)), and free T4 (29.05% (12.79 – 60.49)), with a P-value <0.01. BMI reductions achieved were also statistically significant with a mean % change of −6.78% (−10.34– −3.70), P < 0.01. Conclusion In conclusion, the Mediterranean diet shows promise as a complementary therapy for Hashimoto's thyroiditis, offering lower disease activity, as well as weight reduction. Further research, including randomized controlled trials, is needed for confirmation. Nonetheless, promoting adherence to this diet could offer a safe, accessible, and cost-effective approach to better disease control.