Why are more and more people concerned about thyroid disease?
When it comes to thyroid disease, most people’s knowledge of the thyroid gland used to be limited to “big neck disease”, but why are more and more people concerned about this disease now? I guess it has to do with the following three reasons.
First, in recent years, the incidence of thyroid disease has been increasing, especially with thyroid cancer as the representative. According to the data from the United States, the number of thyroid cancer surgeries has increased by 60% in the past 30 years, and in China, the incidence of thyroid cancer is also rising rapidly, especially in the female group, becoming one of the ten malignant tumors with the highest incidence.
Secondly, with the improvement of living standard, modern people pay more and more attention to health. At present, most units will organize routine physical examination every year, and non-unit people will also do an “annual check-up” for their own body regularly at their own expense. Once the indicators are found to be abnormal, they will start to seek medical advice everywhere, or go online to find the answer themselves.
Third, the ultrasound program is routinely carried out. In the past, the examination of the thyroid gland was often limited to palpation by the doctor, but with the popularity of ultrasound, many small nodules that were previously undetected are nowhere to be seen.
The nuclear leakage incident at Wuhan Union Medical College Hospital, which was a big deal a few years ago, may have caught the attention of many people. The cause of the incident was that four female professors of gynecology at Wuhan Union Medical College Hospital were found to have thyroid cancer at the same time. After investigation, the truth of the matter is that several tests have shown that the radiation levels in the working environment of the female professors suffering from cancer did not exceed the standard. So why was it? In fact, it was not the nuclear leak that caused the cancer in the professors, but the ultrasound that detected the previously undetected lesions. Examples such as these are not uncommon in recent years.
The thyroid gland: a “factory” specializing in the production of thyroid hormones
Having said that, let’s get back to the subject and reacquaint ourselves with the thyroid gland. What is the thyroid gland? In short, the thyroid gland is an endocrine organ in our body whose function is to synthesize and secrete thyroid hormones. The role of these hormones is mainly related to our body’s growth and metabolism, simply put, it is “burn calories, grow, grow brain”.
Is thyroid disease caused by eating?
So, is thyroid disease caused by eating or not? The answer cannot be generalized.
Diet has a certain impact on the thyroid gland, mainly because some ingredients in food may affect the synthesis and secretion of thyroid hormones. However, in addition to diet, thyroid disorders are also related to ionizing radiation, genetics, and stress. In short, thyroid disorders are the result of a combination of internal and external factors!
The component of food most closely related to thyroid disease is the iodine it contains. Why? Let’s look at the following data: a healthy human body contains about 20-50mg of iodine, 70%-80% of which is found in the thyroid gland; iodine is the raw material for synthesizing thyroid hormones and is a trace element needed by the human body on a daily basis; 80%-90% of the iodine needed by the human body comes from food. So is the more iodine you consume the better? Too much or too little iodine intake can lead to thyroid disorders.
For a healthy adult, a daily intake of 150ug-300ug of iodine is appropriate, usually up to 1000ug, and too little iodine may lead to endemic goiter, endemic cretinism or neonatal hypothyroidism, while too much iodine may lead to goiter, hyperthyroidism, part of hypothyroidism and autoimmune thyroiditis. The iodine intake may lead to goiter, hyperthyroidism, hypothyroidism and autoimmune thyroiditis.
What are the foods that we eat every day that have a high iodine content? From the table below, we can see that seafood such as wakame, nori, kelp and seafood are all high in iodine content. In addition, there are also cola, barbecued pork, dried bean curd, which also have relatively high iodine content.
Another issue that we are all concerned about is iodized salt. Some people believe that the mandatory promotion of iodized salt in recent years is the reason for the increase in the incidence of thyroid disease. So is it or not? According to China’s regulations, each gram of salt should contain no more than 20-50ug of iodine, which is 120-300ug according to the World Health Organization’s recommended daily salt intake, which is not excessive for a normal adult’s daily iodine intake.
In fact, in recent years, the implementation of universal salt iodization has done more good than harm, and the incidence of iodine deficiency diseases such as endemic goiter and endemic cretinism, which were common in some iodine deficient areas in the past, has decreased significantly, and the intelligence level of newborns has been effectively improved. As for whether iodized salt causes cancer, there is no reliable evidence to show a direct relationship between salt iodization and the increased incidence of thyroid cancer.
How to eat iodine properly?
Having said that, many people may ask how to consume iodine in a reasonable way. Our answer is that it varies from person to person, from place to place, and from disease to disease.
What does “depending on the person” mean? When people are at different stages, they have different needs for thyroxine, which means they have different needs for iodine. For example, when teenagers are growing up, their growth and metabolism are more vigorous, so they should take more iodine at this time. Pregnant women, in addition to their own supply, also need to provide the thyroid hormone required by the fetus, so they should also eat more food with high iodine content.
”Due to the place”, that is, according to the different environmental iodine content of different areas, iodine intake according to the need. High iodine areas are mainly concentrated in the eastern coast, such as Fujian, Zhejiang, Shandong, etc. Then people in these areas can eat less food with high iodine content in their diet; while inland low iodine areas, they should eat more food with high iodine content.
”Due to the disease”, that is, patients with different thyroid diseases should adjust their recipes according to the condition of their disease. For example, patients with hyperthyroidism, which contains more thyroid hormones, should try to avoid eating foods with high iodine content, so as not to produce too much thyroid hormones in the body and cause aggravation of symptoms; while for patients with hypothyroidism caused by iodine deficiency, they can eat more foods with high iodine content to provide more raw materials for the synthesis of thyroid hormones in the body.
However, there are some special cases, such as patients with Hashimoto’s thyroiditis, where the lesions gradually destroy the normal cells of the thyroid gland, resulting in a decrease in hormone release, or hypothyroidism. So should we eat more food with high iodine content at this time? This is not the case. To use an analogy, the thyroid gland is like a factory, and each cell is like a worker. Without changing the efficiency of work, too much increase in production ingredients does not improve the output of the product, but on the contrary may increase the burden of the workers and affect the internal harmony. Therefore, for Hashimoto’s thyroiditis, one should also try to avoid excessive consumption of foods with high iodine content.
Another question of interest to thyroid cancer patients is whether they can eat iodine-containing foods or not after thyroid cancer surgery. Some studies suggest that limiting iodine intake can reduce the risk of thyroid cancer recurrence and metastasis, but in fact, there is no conclusive answer to this opinion. Unless you are preparing for iodine 131 treatment, you do not need a strict iodine-free diet, just don’t eat too much food with high iodine content at one time.
Having said all this, a brief summary of our opinion is that we should treat the issue of iodine supplementation scientifically, and that a balanced diet, iodine supplementation according to needs and maintaining a dynamic balance of iodine levels in the body is the way to go! The purpose of iodine intake is to synthesize thyroid hormones, so there are two reference standards for assessing whether to eat more or less iodine: one is thyroid function, whether it is hypothyroidism or hyperthyroidism; another more direct assessment standard is urinary iodine. The normal adult urinary iodine level is 100-300ug/L. If it is lower than 100ug/L, then it is iodine deficiency, and it is time for appropriate iodine supplementation; and if it is greater than 300ug/L, then it is iodine overload, and it is necessary to limit the intake of high iodine foods.
Thyroid patients, don’t get hung up on these issues either!
There are many other foods that may be related to thyroid disease, so we will briefly discuss them here for some common questions. The most frequently asked question is whether cruciferous vegetables can be eaten or not. What is the origin of cruciferous vegetables, such as broccoli, cabbage and radish, and the thyroid gland?
In fact, it is mainly related to the presence of a trace substance called thioside. Thioside can be hydrolyzed in the body to produce isothiocyanate, which is similar in composition to thiourea antithyroid drugs and can inhibit the synthesis of thyroid hormones. However, isothiocyanates only play this role when the blood level is high, unless you eat a few pounds at once, there is little effect on the average normal person. In addition, isothiocyanates themselves are also good antioxidants that are beneficial to the human body and can reduce the risk of cardiovascular disease and certain cancers such as lung, colon and breast cancer. With that said, you should also understand whether you should eat it or not, and whether you can eat it.
Secondly, there are some popular sayings that you can’t eat beef and mutton, dairy products and other “hairy” things with thyroid nodules, which will easily cause the nodules to grow. The answer is “no”. There is no reliable evidence to prove that the consumption of beef, lamb and dairy products is directly related to the occurrence of thyroid disease, so our view is that we should eat as much as we like, but of course everything should be done in moderation.
Finally, let’s talk about what to look for when taking thyroid-related medications. Thyroid medications can be divided into two categories, depending on their effects. One type is the supplemental thyroid hormone, which is often referred to as Eugenol. Some soy products such as soy milk and tofu may affect the absorption of the drug, so try to avoid eating these foods before and after taking the drug.
There is another category of thyroid hormone lowering, called anti-thyroid drugs, such as Sage, propylthioxypyrimethamine, mainly for the treatment of hyperthyroidism. The actual fact is that when you take this kind of medication, you can eat a little more cruciferous vegetables, which can play a synergistic role, but of course, it is also based on your personal preference. In the end, medication is the key, and the overall goal is to keep the thyroid function in the normal range.
How about it, now do you know what thyroid disease and diet have to do with each other?