Unless you suffer from a problem with it, you probably don’t think much about the thyroid gland – the little, butterfly-shaped organ which sits at the base of the front of your neck, below your Adam’s apple and alongside your windpipe. Carol Wilson, my sister and a science teacher in the UK, had certainly never given this part of her anatomy a thought – until she awoke one morning with an odd sensation in her throat. “It wasn’t sore,” she recalls, “but it felt as if I’d swallowed a golf ball.” An ultrasound revealed she had nodules in her thyroid, a gland important in helping to regulate metabolism and body temperature. Wilson’s experience, in her mid-20s, is not unusual; thyroid issues present far more often in women than men – possibly as much as eight times more; some experts believe as many as 30 per cent of women will develop a condition of the thyroid in their lifetime, and nodules – such as those that presented in her case – are among the most common. According to Dr Elaine Cheung Yun Ning, a Hong Kong specialist in endocrinology, diabetes and metabolism, the most common thyroid diseases include hyperthyroidism – an overactive thyroid which presents with tremors and palpitations; hypothyroidism – when the thyroid is underactive and the patient lacks energy and may be prone to weight gain; and nodules, like those Wilson had. Diseases of the thyroid have been observed for thousands of years. In 1600BCE, seaweed – which contains iodine – was used in China for the treatment of goitre, a non-cancerous enlargement of the thyroid gland. The most common cause of goitre worldwide (the condition affects up to 800 million people globally) is an iodine deficiency in the diet. Jet Li and hyperthyroidism: the illness haunting martial arts superstar The Greek philosopher Aristotle referenced goitre, and Greek physician Hippocrates and Plato described the gland itself, proposing its function as a salivary gland. Italian polymath Leonardo da Vinci was the first to provide an illustration of the gland – which wasn’t called thyroid until 1656, when the anatomist Thomas Wharton named it after its shape; the name is derived from a Greek word meaning shield-like. Although goitre are usually painless, a large goitre can cause a cough and make it difficult to swallow or breathe. To sustain thyroid health, and healthy production of thyroxine, an important hormone, we need iodine, which is commonly found in seafood, dairy products, and eggs – and in iodised table salt. A French chemist discovered iodine in 1811 and a little under a century later it was established as a key component of the thyroid. Wilson had no idea of its place in the thyroid until she developed a problem. She knew about iodine, though: “a grey solid that turns into a purple gas”. To excise the nodules that had developed, Wilson had half her thyroid surgically removed. Cheung says this is common. “Patients with certain thyroid diseases may need to have their thyroid removed. And then they need to be put on long-term thyroxine replacement. With optimal replacement and monitoring, they can live a totally normal life and have a normal life expectancy,” she says. The remaining half of Wilson’s thyroid functions well enough for her not to need replacement thyroxine, though she has been warned this may change in the future, as she ages. She is now 48. So how do we look after the little gland? Cheung recommends avoiding medication or food which may affect thyroid function. This means cutting out highly processed foods packed with sugar or sugar-free substitutes, preservatives, MSG, and fat. It may come as a surprise, but some cruciferous vegetables such as cauliflower, cabbage, kale, kohlrabi, watercress, bok choy, and Brussels sprouts can be problematic, also. They may be packed with good nutrients such as vitamin C and folate, but eating them raw in large amounts could mess with your thyroid, as they contain natural chemicals – goitrogens – which can interfere with hormone production. Steaming or boiling them will rid them of up to 90 per cent of the goitrogens. Environmental hazards can upset thyroid function, too. Non-stick cookware, for example, was linked to thyroid disease in a 2010 study. A later study found that exposure to soft plastics may also disrupt healthy thyroid function. It might not be possible to avoid these altogether, so the key is to minimise exposure: choose fresh food rather than frozen or tinned, and store food in glass or ceramic containers rather than plastic ones. Why thyroid problems should be examined by health professionals Other ways to support thyroid health are no different from supporting good overall health: being physically active, getting enough sleep, and eating a healthy diet. Clinical studies suggest that taking a daily dose of the mineral selenium can support the thyroid – but you’d get all the selenium you need from eating a couple of Brazil nuts every day. Three other conditions that affect the thyroid are Hashimoto’s, Graves disease and cancer . Hashimoto’s is the most common cause of hypothyroidism and is most common in middle-aged women. It develops when the body’s immune system attacks and destroys the thyroid gland and its ability to produce hormones. Graves disease – named after the doctor who first described it a century and a half ago – is also an autoimmune disease and is the most common cause of hyperthyroidism in young women. Cancer of the thyroid often presents as a swelling, not dissimilar to Wilson’s. Happily, as in her case, most nodules are benign, only 5 per cent prove malignant. The thyroid – fact or fiction Fiction: a lump or nodule in the thyroid means you have thyroid cancer. Fact: only 5 per cent of thyroid nodules are cancerous. Fiction: all people with thyroid problems have bulging eyes. Fact: bulging eyes are just one symptom of a thyroid problem, most common with hyperthyroidism. Fiction: only middle-aged or older women have thyroid problems. Fact: men and women can develop thyroid disease at any age. One in five women develop thyroid problems by the age of 60. Fiction: thyroid problems are best diagnosed by identifying symptoms. Fact: about 60 per cent of people with thyroid disease don’t know they have it. Fiction: you can’t lose weight with hypothyroidism. Fact: if your dosage of medicine is effective, hypothyroidism won’t affect your ability to lose weight.