Firstly, why is the thyroid so important?
“The thyroid gland influences almost all of the metabolic processes in the body. The two hormones made by the thyroid help regulate the metabolism and impact how fast your heart beats, how deep you breathe and whether you lose or gain weight. It also controls body temperature, cholesterol levels and menstrual cycles. These two hormones, known as T-3 and T-4, are released by the thyroid into the bloodstream, and sent through the body.” – Dr Michael Mosley, creator of the Fast 800
What are the signs your thyroid is out of balance?
“Over or under-active levels of thyroid hormones are relatively common conditions, but can lead to a range of symptoms. Excess levels of thyroid hormones (hyperthyroidism) can dangerously speed up the body’s metabolism. This can cause issues including hyperactivity, mood swings, insomnia, excess sweating, unexplained weight loss, and light or infrequent periods. It can be tricky to spot the signs of an underactive thyroid (hypothyroidism), as many of the symptoms are the same as other conditions. These include tiredness, sensitivity to the cold, weight gain, constipation, depression, slow movement and thoughts, muscle weakness and cramps, dry and scaly skin, brittle hair and nails, heavy or irregular periods and loss of libido.” – Dr Michael Mosley
How does the thyroid get out of whack in the first place?
“There can be genetic or lifestyle factors. Most underactive thyroid cases are caused by the immune system attacking the thyroid gland. This damages the thyroid so it can’t make enough of a hormone called thyroxine. An underactive thyroid can also occur due to treatment for an overactive thyroid, or as the result of thyroid cancer. Another cause in the UK is a lack of dietary iodine, as the body needs iodine to make thyroxine. We get most of our iodine from white fish or milk; if you don’t consume either, you may want to consider eating seaweed (a very rich source of iodine) or supplementing. Hypothyroidism can also be hereditary. Those with overactive thyroids may have Graves’ disease, an autoimmune condition in which the immune system attacks the thyroid. This mostly affects young to middle-aged women, and is hereditary. Other things that can affect the thyroid gland are stress, nutritional deficiencies, glandular fever, major trauma such as a car accident, and pregnancy.” – Dr Michael Mosley
How common are thyroid problems?
“More common than you think. Women are ten times more likely to be affected by thyroid imbalances than men due to the delicate female hormonal cycle. In periods of hormonal unrest, such as childbearing, or emotional, physical and mental stress, women are especially prone to be affected.” – Dr Ursula Levine, GP at Lanserhof at The Arts Club
“An underactive thyroid, is more common than an overactive one. But you can start with an overactive thyroid which then becomes underactive, or vice versa. According to the National Institute for Health & Care Excellence (NICE), hypothyroidism is found in about 2% of the UK population, affecting 1 in 50 women. Hyperthyroidism is also more common in women than men. Doctors don’t know why this is, but it could be because autoimmune conditions are also more common in women.” – Dr Michael Mosley
Can the thyroid affect fertility?
“If you have an underactive thyroid, this can interfere with ovulation, which will impact your fertility. You may also have longer or heavier periods, or your periods can stop completely, which will make it harder to conceive. Graves’ disease is the most common cause of an overactive thyroid. The condition can cause lighter, irregular periods, which can make it difficult to conceive. The good news is pregnancy can happen as normal once your thyroid function is balanced, so make sure you check in with your GP if you are planning on getting pregnant.” – Dr Michael Mosley
What can your GP do if you think your thyroid needs some TLC?
“Your GP can do a thyroid function test, which looks at levels of thyroid stimulating hormone (TSH), which controls the production of thyroid hormones, and thyroxine (T4) in the blood. A high level of TSH and low level of T4 could mean you have an underactive thyroid. Your GP will also be able to test for an overactive thyroid. The blood test will check levels of your TSH, T3 and T4 hormones.” – Dr Michael Mosley
Is medication always the best solution?
“Taking medication can help maintain normal thyroid levels, but eating a balanced diet and taking the right supplements can also help, and reduce the risk of inflammation. Iodine is the most obvious supplement to take for thyroid health. The UK is one of the most iodine-deficient countries in the world because we don’t add iodine to salt as many other countries do. This is a particular problem for pregnant women as their iodine requirement is 50% greater than for non-pregnant women.” – Dr Michael Mosle
How can you eat to support your thyroid?
“One of the most important things you can do to maintain a healthy thyroid is eat a well-balanced, Mediterranean diet. About 70% of our autoimmune system is found in the gut. When this is inflamed, an immune response is triggered, which can play a role in the development of thyroid disease. To reduce the risk of inflammation, follow a Mediterranean diet, which is widely seen as the most nutrient-rich diet on the planet, containing lots of vegetables, fruit, whole grains, lentils, beans, nuts, seeds, spices and olive oil, as well as some oily fish, cheese and full-fat yoghurt. It’s also important to try and avoid processed foods like takeaways, as they can cause autoimmune flare-ups. I usually advocate eating a wide variety of vegetables, but for people with thyroid issues, avoid raw cruciferous veggies like cauliflower, cabbage, kale and Brussels sprouts. Uncooked, they contain certain chemicals that can interfere with thyroid hormone synthesis.” – Dr Michael Mosley
If our immune system is closely linked to our gut, does gut health also play a role in thyroid conditions?
“Quite possibly. Science shows gastro-intestinal function and bowel integrity can be impacted by alterations in cellular thyroid physiology. Leaky gut syndrome also increases the risk for autoimmune thyroid disorders. In the onset, the inflammation can result in an overproduction of thyroid hormones. When the inflammation persists, it can prevent the thyroid from producing enough hormones.” – Dr Ursula Levine
“As the thyroid affects every system in the body, it’s not surprising it can have a big effect on the gut. Hashimoto disease, which is the most common cause of hypothyroidism, can lead to nausea, heartburn and vomiting because the stomach is slow to empty. For similar reasons you can also get wind, bloating and constipation.” – Dr Michael Mosley
Can thyroid issues cause food intolerances and vice versa?
“Although hypothyroidism isn’t known to cause food intolerances, the two conditions may coexist. A recent study found the blood of 4.6% of participants indicated signs of coeliac disease, and 2.3% of the participants tested positive for the disease – a prevalence markedly higher than in the general population.” – Dr Michael Mosley
Ultimately, what’s the one thing we can all do for better thyroid health?
“Make sure you are getting enough iodine in your diet. If you are drinking cow’s milk you are probably fine, but nut milks contain hardly any iodine. Try to eat a couple of portions of white fish a week, and try seaweed. Some cheeses have decent amounts of iodine, including mozzarella. A healthy diet can improve the body’s ability to absorb hormones, and is a simple, tasty way to help with the effects of an imbalanced thyroid.” – Dr Michael Mosley
“Consider your lifestyle choices. Reduce stress; increase the amount of exercise you go; and aim for a healthy diet that excludes refined grains, sugars, soy products, peanuts and caffeine. Also try to stop smoking and limit your alcohol consumption.” – Dr Ursula Levine
If you think you are suffering from a thyroid imbalance, your GP should be your first port of call. For more information visit the NHS.
*Features published by SheerLuxe are not intended to treat, diagnose, cure or prevent any disease. Always seek the advice of your GP or another qualified healthcare provider for any questions you have regarding a medical condition, and before undertaking any diet, exercise or other health-related programmes.