Patients suffering from Hashimoto’s thyroiditis have two reasons why they may avoid consuming dairy products. The first reason is that Hashimoto’s thyroiditis patients are more likely to have food sensitivity to dairy proteins, meaning that the immune system becomes reactive to the proteins found in dairy products. The food sensitivity will lead to the production of inflammation chemicals by the immune system when you eat dairy and inflammation chemicals can affect your energy, your mental and physical health.
The second reason is lactose intolerance, which has to do with the genetically inherited inability to produce adequate amounts of lactase, which is the digestive enzyme that allows the break down of lactose into its simple sugar components. It turns out that patients with Hashimoto’s thyroiditis have a higher incidence of lactose intolerance. Lactose intolerance can cause gastrointestinal symptoms such as abdominal bloating, cramps, diarrhea, and nausea.
You need to be aware that if you have lactose intolerance you may suffer from poor absorption of essential nutrients and even medications. Because patients with Hashimoto’s thyroiditis may be treated with thyroid hormone medications, the absorption of their thyroid hormone medication may be affected because of the lactose intolerance issue.
This is the reason why if you have Hashimoto’s thyroiditis and are taking thyroid medication you may have unstable thyroid tests over time, and when you limit your lactose intake, the dose of thyroid hormone medication may need to be reduced simply because the absorption of thyroid hormone has improved.
You also need to be aware that some thyroid hormone medications (i.e. Levothyroxine) may contain lactose themselves as part of the inactive ingredients of the tablet. When this is the case, the medication itself can contribute to malabsorption of the active form of thyroid hormone and can even promote symptoms if you have lactose intolerance.