Can thyroid function be influenced by exercise and diet? i was told no. i find that difficult to believe. what is the truth?

Not true: Actually there are those that believe that diet and exercise can influence the thyroid. I am among them. The question is really "how much?" that is a tougher answer. I believe that regular exercise can improve thyroid function. Naturapathic doctors use a combination of different foods to treat thyroid deficiency. I am not aware of any data to support this but have seen it be effective.

Somewhat: Exercise promotes mitochondrial biogenesis. Since thyroid cells have mitochondria, exercise can be good for the thyroid as well. Cadmium is excreted in sweat, so exercise can also promote heavy metal detox. Some foods are goitrogens, such as soy. Foods that contain iodine can help support thyroid function. Foods with lead or mercury can add to the toxic load. Beware bpa and phthalates too.