Different studies and meta-analyses found that the intake of foods and supplements such as fruits, vegetables, milk and dairy products, seafood and moderate amounts of genistein may be beneficial in reducing the risk of thyroid cancer, and may possibly alleviate the symptoms and support treatment of this cancer. However, relatively low and extremely high intake of dietary iodine, intake of starchy and sugary foods and foods that cause obesity may increase the risk of this cancer. Hence, following a personalized nutrition plan with the right foods and supplements included and staying physically active are essential when it comes to cancer care and prevention.
Thyroid Cancer Incidence
Thyroid cancer is a type of cancer which affects the thyroid gland, a small butterfly-shaped gland located at the base of our neck. Thyroid cancer is also one of the most common types of endocrine cancer. According to the American Cancer Society, about 44,280 new cases of thyroid cancer may be diagnosed in 2021.
Thyroid cancer is commonly seen in people in their 30s and above, however, it can develop at any age. Women are more likely to develop this cancer than men. Exposure to radiation in the head or neck is one of the common risk factors of thyroid cancer.
The four types of thyroid cancers include:
- Papillary Thyroid Cancer – found in 80% of thyroid cancer cases; grows slowly, but may spread to lymph nodes in the neck.
- Follicular Thyroid Carcinoma – second most common thyroid cancer; Hurthle cell cancer is a rare and more aggressive type of follicular thyroid cancer.
- Medullary Cancer – a rare type of thyroid cancer; spread/metastasis to the lymph nodes is common at the time of diagnosis
- Anaplastic Thyroid Cancer – least common type of thyroid cancer; tumors grow rapidly and spread to other parts of the body; hardest to treat
Symptoms of Thyroid Cancer
During the early stages of thyroid cancer, there may not be any signs or symptoms. However, as the disease progresses, it may lead to many symptoms of cancer including:
- A lump (nodule) in the neck that might grow quickly
- Increasing hoarseness and other voice changes
- Difficulty in breathing
- Difficulty in swallowing
- Persistent cough – not due to a cold
- Pain in the throat and neck going up to the ears
- Painless swelling in the neck
Many of these symptoms may also be seen in other non-cancerous health conditions and may not necessarily be due to thyroid cancer. However, if you experience any such signs or symptoms related to throat cancer, consult your doctor immediately.
Treatment Options for Thyroid Cancer
The treatment of thyroid cancer is decided based on different factors including the type of cancer, extent of spread or stage of the cancer, general health and medical history of the patient. In many cases, thyroid cancers can be cured with treatment.
People with thyroid cancer may have to undergo surgery to remove the thyroid, post which they are often treated with thyroid hormone therapy. Radioactive iodine treatment is also often used after thyroid removal to destroy any remaining thyroid tissue that wasn’t removed during surgery. Other treatments for thyroid cancer include radiation therapy, chemotherapy, targeted drug therapy and supportive (palliative) care.
Association of different Foods and Lifestyle Factors with Thyroid Cancer Risk
When it comes to any cancer including thyroid cancer, following a personalized diet including the right foods and supplements and a healthy lifestyle becomes crucial. Below are some examples of studies which evaluated the association of different foods and lifestyle factors with the risk of thyroid cancer.
Relatively Low and Extremely High Intake of Dietary Iodine may Increase the Risk of Thyroid Cancer
Researchers from the Soonchunhyang University College of Medicine and Sungkyunkwan University School of Medicine in Korea analyzed the Urinary Iodine concentration (UIC) data from 1170 patients with thyroid nodules and found that a relatively low iodine intake corresponding to UIC <300 μg/L and extremely excessive iodine intake corresponding to UIC ≥ 2500 μg/L may increase the risk of thyroid cancer in an iodine-replete area in Korea. (Hye Jeong Kim et al, Eur J Nutr., 2017)
Another study done by the researchers from Soonchunhyang University College of Medicine and Sungkyunkwan University School of Medicine in Korea also found that relatively low iodine intake corresponding to UIC < 300 μg/L and more than excessive iodine intake corresponding to UIC ≥ 500 μg/L can also increase the risk of occurrence of BRAF mutations in the thyroid which may result in the development of papillary thyroid cancer. (Hye Jeong Kim et al, Eur J Nutr., 2018)
Intake of Starchy and Sugary Foods may Increase the Risk of Thyroid Cancers
Researchers from the Istituto di Ricerche Farmacologiche Mario Negri Milan, Italy analyzed data from a case control study conducted in Italy between 1986 and 1992 involving 399 thyroid cancer cases and 616 controls and found that starchy and sugary foods which are known to have high levels of glycemic index and glycemic load (measure of the potential to raise blood sugar levels) may increase the risk of thyroid cancers. (G Randi et al, Ann Oncol., 2008)
Intake of Vegetables, Milk products and Seafood may Reduce the Risk of Thyroid Cancer
In a hospital-based study in Sicily (South Italy), the researchers from the University of Catania analyzed the dietary information from 106 thyroid cancer patients and 217 controls who were recruited at the University Hospital G. Rodolico of Catania and concluded that following a diet with limited starchy foods and products rich in salt, fat and sugar, and a higher consumption of cruciferous/non-cruciferous vegetables, milk and dairy products and seafood along with 1 to 2 L of daily water intake may help in reducing the risk of thyroid cancer. (Maria Fiore et al, Food Chem Toxicol., 2020)
Another study done by the researchers from the Yale School of Public Health New Haven and Miami Cancer Institute in the US, and Peking Union Medical College Hospital-Beijing, Sichuan University and Capital Medical University, Beijing in China also found that those who followed dietary patterns rich in fruits and vegetables had a reduced risk of thyroid cancer, especially among women aged 50 years or older. They also found that the risk of thyroid cancer increased among men with a high intake of starchy foods and desserts. (Jiaxin Liang et al, Am J Transl Res., 2020)
Intake of Moderate amounts of Genistein may Reduce the Risk of Thyroid Cancers in Females
Researchers from the Icahn School of Medicine at Mount Sinai in New York, Yale University in Connecticut, Miami Cancer Institute in Florida and Chinese Academy of Medical Sciences and Capital Medical University in China, analyzed data from a population-based study conducted in Connecticut from 2010 to 2011, including 387 thyroid cancer cases and 433 population-based controls, and found that intake of moderate amounts of genistein may reduce the risk of papillary thyroid macro-carcinomas, with tumor size >1 cm in diameter, in females. (Qian Wang et al, Cancer Epidemiol Biomarkers Prev., 2020)
Adolescent overweight and obesity may Increase the Risk of Papillary Thyroid Cancer in Adulthood
Researchers from the Seoul National University and Ewha Womans University College of Medicine in Seoul, Korea analyzed data from a case-control study conducted in the Republic of Korea involving 1,549 papillary thyroid cancer patients and 15,490 controls and found that adolescent overweight and obesity was associated with a higher risk of papillary thyroid cancers in adulthood. (Kyoung-Nam Kim et al, Sci Rep., 2020)
Hence, reduce the intake of obesity causing foods such as red and processed meat, fried foods, processed foods and other fast foods to reduce the risk of thyroid cancer.
Association between Alcohol and Thyroid Cancer Risk
Researchers from the Shinhan University in Uijeongbu and National Cancer Center in Goyang, Korea did a meta-analysis of 3 observational studies, 20 case-control studies, and 11 population-based studies, involving a total of 7,725 thyroid cancer patients and 3,113,679 participants without thyroid cancer, obtained through literature search in Pubmed and Embase databases and found that unlike most of the other types of cancer, alcohol intake decreased the risk of thyroid cancer. (Seung-Hee Hong et al, Cancer Res Treat. 2017)
Different observational studies and meta-analyses indicate that following a diet containing foods such as fruits, vegetables, milk and dairy products, seafood and moderate amounts of genistein may be beneficial in reducing the risk and may possibly even alleviate the symptoms and support treatment of thyroid cancer. However, relatively low and extremely high intake of iodine, intake of starchy and sugary foods high in glycemic index and foods that cause obesity such as red and processed meat as part of the diet, may elevate the risk of thyroid cancer. Taking the right foods and staying physically active is essential when it comes to cancer care and prevention.
Cancer patients often have to deal with different chemotherapy side effects which affect their quality of life and look out for alternative therapies for cancer. Taking the right nutrition and supplements based on scientific considerations (avoiding guesswork and random selection) is the best natural remedy for cancer and treatment related side-effects.