Doctors from UCLA Health addressed concerns on Mar. 9 regarding the relationship between Hashimoto’s disease, thyroid cancer risk, and dietary restrictions. The discussion was prompted by a question from a reader whose friend with Hashimoto’s disease feared developing thyroid cancer and had encountered strict dietary advice online.
Hashimoto’s disease is an autoimmune disorder that affects the thyroid gland, which plays a key role in regulating metabolism, heart rate, body temperature, brain development, bone health, and weight management. In this condition, the immune system attacks the thyroid tissue, leading to reduced hormone production over time. Symptoms can include fatigue, dry skin, muscle weakness, facial puffiness, brittle nails, constipation, hair loss, swollen tongue, increased sensitivity to cold, sleepiness or depression, and changes in menstrual cycles. Diagnosis is made through blood tests and treatment options range from monitoring to hormone replacement therapy.
The doctors said that “Hashimoto’s disease is not considered to be a precancerous condition.” However, they noted that some studies have found higher rates of papillary thyroid cancer among people with Hashimoto’s disease. The cause of this association remains unclear but may involve chronic inflammation common in autoimmune diseases.
Regarding diet recommendations circulating on social media—such as avoiding gluten, dairy products, tofu or tomatoes—the doctors explained these are based on specific considerations. Gluten avoidance is suggested because celiac disease often co-occurs with Hashimoto’s; both are autoimmune conditions. Dairy products may be restricted due to lactose intolerance symptoms overlapping with those of celiac disease. Tofu avoidance relates to evidence that soy compounds can reduce absorption of levothyroxine—a synthetic hormone used in some thyroid treatments. Tomatoes are sometimes avoided due to ongoing debate about whether nightshade vegetables contribute to inflammation.
The doctors emphasized that their overview should not be taken as medical or dietary advice but rather as information for patients to discuss with their healthcare providers: “While our overview can be helpful to your friend, this is not medical or dietary advice. Instead, we hope that they will use the information to craft questions to ask their own medical team. Each case of every disease is unique to the patient and needs guidance specific to their needs and circumstances.”
