The thyroid

I’m often asked “Is there a diet for underactive thyroid?”

There isn’t, but what you eat can affect thyroid function. Confused? Read on!

Approx read time: 4 mins
Woman sleeping, hugging a cushion.

What is the thyroid?

The thyroid is a gland in the neck, about the size of a plum and weighing less than a slice of bread.

Despite its diminutive size and weight the thyroid has a huge amount of control over the way the body works, in particular the speed at which body cells work – such as metabolism, breathing, heart rate, rate of digestion, nervous system function, menstruation, body temp, cholesterol levels and more.

What does the thyroid do?

The thyroid secretes two hormones, called T3 and T4. T4 gets converted to T3, so really it’s *all* about the T3 in the end. Simplifying it quite radically, these two hormones are made from iodine bound with a protein, therefore healthy thyroid function relies heavily on there being enough iodine in the diet.

By the way, dairy is a great source of iodine, so cutting dairy can significantly affect thyroid function.

The head honcho, the director of the Thyroid Department if you will, is the hypothalamus in the brain. The hypothalamus tells the pituitary how much thyroid hormone should be in the blood.

The pituitary gland is a sort of thyroid ‘thermostat’ because it detects the level of T3 and T4 in the blood then sends a message to the thyroid telling it to secrete more or less hormone to keep a balance. But instead of sending an email 🙂 it sends thyroid stimulating hormone, or ‘TSH’.

So to make it clearer:

Big Boss hypothalamus: “Pituitary, I have set the goal-level of thyroid, go out and check it constantly!”

Middle manager pituitary: “Ok boss!” Goes out to check ALL THE TIME. Sends email to its assistant, the thyroid gland: “THYROID LEVELS ARE LOW, SECRETE MORE HORMONE!”

Minion thyroid: “OK boss!” Then. “Oh bugger, I’m pranged up and can’t come to work today, or ever, really.” Or “This is not even my fault, it’s a failure of the Pituitary or hypothalamus, they’re not giving me the right instructions, yet I’m the one who gets it in the neck!” (Scuse pun..)

What can go wrong?

The thyroid can start to produce too much or too little hormone. More commonly, too little, which is what this article is about.

This is known as hypothyroidism and needs treating with lifelong drugs as it doesn’t correct itself. Some potential causes are pregnancy (this can be temporary or lasting hypothyroidism), certain drugs, Hashimoto’s Disease, autoimmune disfunction, chronic inflammation, chronic stress, over-exercising and heredity. 

Ten times more women than men have hypothyroid and 1 in 20 people in the UK are sufferers.

Just to reiterate, it might not even be the thyroid gland’s direct fault, it may be a problem with the pituitary or hypothalamus giving wrong instructions.

What are the symptoms of hypothyroid?

Too many to list but the more common ones are:

  • unusual tiredness and fatigue,
  • feeling the cold more than usual; general temperature fluctuations,
  • muscle weakness,
  • hair loss,
  • eyebrow thinning,
  • poor nail quality,
  • slow weight loss,
  • low heart rate,
  • depression and anxiety.

Is there a diet for underactive thyroid?

Because the thyroid controls metabolism an underactive thyroid, if left untreated, can make it more difficult to stay at a healthy weight.

Moreover it can be hard for medical practitioners to get drug dosage right and even when a person’s thyroid readings are ‘normal’ they can still be heavily symptomatic because the levels are not normal for *them*. It’s often a case of trial and error.

There is no dietary intervention to address hypothyroidism but it’s essential to get enough iodine in the diet. The richest sources of iodine are non-oily fish and dairy products, and to a far lesser extent shellfish, meat and poultry. We bear this – and many other factors – in mind when we write the Nutrition for Everyone plan each week.

If you’re already taking thyroid medication, it’s really important to take it away from eating times as some foods can hinder absorption, particularly calcium-rich foods and soya.

So there you have it – although it’s a vast topic, much vaster than I can cover here!

Do you want better health?

The Nutrition for Everyone plan will help you maximise the essential nutrients your body needs for robust health.

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Thank you for reading this article. Please note that while we share a lot of awesome information and research you should be aware our articles are strictly for informational purposes and do not constitute medical advice intended to diagnose, cure, treat or prevent any disease.