Health Claims

These three drugs don’t block the pituitary’s response to a brain signal that turns on the thyroid, so they probably stop the signal earlier—right in the brain—when it comes to cold-triggered thyroid activity.

When animals get cold, their brain tells their thyroid to speed up their metabolism through nerve signals, and certain drugs can block this — showing it's controlled by the nervous system.

The way your body handles stress might change in conditions like chronic fatigue and fibromyalgia — and that change could actually be your body trying to cope, not something broken.

People with chronic fatigue or fibromyalgia often have low cortisol, but it's not because their brain or hormone glands are damaged — it's more about how the system is working, not broken parts.

People with chronic fatigue or fibromyalgia often have a sluggish stress-response system and lower-than-normal cortisol levels, but not every study agrees because they look at different people or use different methods.

Your thyroid can still work normally even if you're not getting quite enough iodine, thanks to built-in backup systems that kick in for months or years.

People who don’t get quite enough iodine don’t seem to have a clear difference in thyroid problems compared to those who get enough — most studies show no big link, even though a few suggest there might be a small risk.

We don't have strong enough proof to say whether mild or moderate iodine deficiency really affects thyroid function, because the studies done so far aren't very reliable or consistent.

For kids, teens, and adults, not getting quite enough iodine doesn’t seem to clearly affect thyroid hormone levels — some studies see no change, others see mixed results, so we can’t say for sure either way.

Pregnant women with slightly low iodine levels don’t seem to have noticeable changes in their thyroid hormones compared to those with good iodine levels — their thyroid still works fine even if their iodine isn’t perfect.

Not getting enough iodine when kids are growing can hurt their brain development for good, because iodine is needed to make important brain hormones.

If jade perch on fish farms are fed homemade food that's really low in iodine and vitamin C, they might end up with thyroid problems — and this was seen in real farm conditions by checking the food and the fish's tissues.

Fish raised on farms might get thyroid tumors over time if their food lacks important nutrients, and we've seen signs of this in jade perch that were fed a poor diet.

Farmed jade perch are getting tumors in their thyroid because their food is missing important nutrients like iodine and vitamin C — scientists found this by checking the fish tissues and their feed.

When baby zebrafish have higher stress hormone levels early in life, it seems to change how certain genes in their brain work—turning down one gene linked to stress control and turning up another—hinting at how early stress might rewire their stress response system.

Scientists used light to turn on special cells in baby zebrafish that make a stress hormone, and found it stayed high for a long time — showing a new way to study long-term stress in developing fish.

If baby zebrafish have too much of a stress hormone early in life, they might not react as strongly to stress later on — like their stress system gets 'numb' and stays that way.

Most thyroid lumps in adults from iodine-poor areas of Russia are harmless, and only a tiny fraction look suspicious for cancer under the microscope.

In parts of Russia where people don’t get enough iodine, about 1 in 5 adults has a swollen thyroid gland, based on ultrasound checks done in large health surveys.

In some parts of Russia where people don’t get enough iodine, lots of adults have lumpy thyroid glands, and most of those lumps are harmless. In two areas, Chechnya and Tula, over half and nearly half of adults had these lumps when checked with scans and tests.

Being around blue light at night, like from phones or screens, might keep your body from making the sleep hormone melatonin because it keeps stress hormone levels high, making it harder to fall and stay asleep.

Your thyroid evolved when humans ate lots of animal foods high in zinc, iron, and magnesium, so these nutrients might be the best for keeping it working well.

Not getting enough iodine might cause abnormal cell growth in important glands and organs like the thyroid, breasts, uterus, and prostate.

Eating fat from animal foods gives your body cholesterol that it needs to make important hormones, and it might also help keep your blood sugar and stress levels steady.