Is Soybean Good For Thyroid Patients?
Discover whether soybean is beneficial or harmful for thyroid patients. Learn about its impact on thyroid function, potential risks, and how to include it in a balanced diet safely
Written by Dr Sonia Bhatt
Last updated on 12th Mar, 2025
The thyroid gland is one of the most critical organs of the human body as it releases hormones that regulate the main metabolic functions of the human body. So, the importance of this organ cannot be stressed enough, and taking effective care of it is imperative. In this regard, the role of diet and the right food is crucial, and one item that needs special mention is soybeans.
Soybeans contain nutrients that are beneficial to the body. Having the characteristics of protein, they include essential amino acids and isoflavones, which are plant-derived oestrogens, also known as phytoestrogens. Furthermore, it comes with vitamins like folic acid vitamins and minerals, such as magnesium and potassium. All these together give soybeans a great nutrient profile, which also helps in curbing thyroid-related issues.
The Role of Soybean in Thyroid Function
Soybean plays a key role in managing thyroid functions; here are the details –
Soybean and Thyroid Hormone Production
Thyroid hormone synthesis needs iodine, and the constituents in soybeans reduce iodine absorption and lower the production of thyroid hormones. Therefore, people with adequate iodine in their bodies are not affected, but for those who suffer from iodine deficiency, over-consumption of soybeans further worsens their thyroid disorders, leading to hypothyroidism.
Impact of Isoflavones on Thyroid
Soy contains isoflavones, which behave like the female sex hormone, i.e., oestrogen. Isoflavones can help regulate hormones, especially oestrogen, which is necessary for all women in the period of menopause. They can also fluctuate thyroid hormone levels or interfere with thyroid hormone drugs in high doses.
The overall impact of isoflavones on thyroid function is not conclusive as various factors like age, diet, medication, and current health condition determine the final outcome.
Benefits of Soybean Consumption
Soybean offers a host of benefits, and here is all you need to know –
Soybean as a Source of Protein
It has the ability to replace animal protein, and for individuals seeking plant-based protein options, it offers a great alternative. It has all nine essential amino acids that the human body cannot produce on its own.
The amino acids in soy protein support muscle recovery and growth, making soy an excellent option for athletes and active individuals. Soybean promotes satiety. Hence, it reduces hunger and helps in weight management.
Soy products like tofu, tempeh, and soy milk serve as effective substitutes for meat and dairy items. It has the similar protein levels but not the saturated fats.
Other Health Advantages of Soybean
In addition to protein, soybeans offer the following perks:
- Betters Heart Health: Soybeans have isoflavones and unsaturated fats, which help reduce bad cholesterol (LDL) and enhance good cholesterol (HDL).
- Improves Bone Health: The calcium, magnesium and phosphorous content of soybean helps improve bone health and lower the chances of osteoporosis.
- Reduces Oxidative Stress: Antioxidants present in soybeans reduce oxidative stress and lower the chances of chronic diseases such as cancer and diabetes.
- Elevates Digestive Health: Soybeans are filled with dietary fibre, which promotes gut health through regular bowel movement and by fostering healthy gut bacteria.
Potential Risks and Concerns
The risks and concerns related to the usage of soybeans include the following –
Goitrogenic Effects of Soybean
Soybeans are among the food items that affect the iodine absorption by the thyroid gland. Hence, they are also known as goitrogenic foods, and excessive consumption may lead to –
- Reduced levels of thyroid hormones
- Hypothyroidism, and goitre in particular, in iodine-deficient groups
Another fact about the use of soybeans is that raw or unprocessed soy have high goitrogen substances that are dangerous to thyroid patients. But, when you cook soybeans, the goitrogenic activity is significantly limited, making them safer for thyroid patients.
Interaction with Thyroid Medications
Soybeans can reduce the effectiveness of thyroid hormone replacement drugs, including synthetic thyroxine (levothyroxine). This interaction may lead to:
- Decreased efficacy of medications
- Thyroid hormone changes
Research Findings and Clinical Studies
Research highlights both the benefits and risks of soy for thyroid health. Here are some highlights –
- According to Harvard Health, people with normal iodine consumption and moderate soybean consumption will not harm the thyroid gland.
- In its guidelines, the Endocrine Society has cautioned that those consuming large amounts of soybeans may need to change the prescribed dose of thyroid hormone medication for hypothyroidism.
Expert Opinions and Recommendations
It is important to take moderate amounts of soybean and associated foods for patients who are suffering from thyroid disorders. The common belief is that soybeans are not unsafe for thyroid health as long as people consume enough iodised foods and avoid taking soy products together with thyroid medicines.
Dietary Considerations for Thyroid Patients
Here are some dietary considerations that thyroid patients must pay attention to –
Recommended Soybean Intake
For thyroid patients, moderation is key:
- Limit soy consumption to 1-2 servings daily, such as:
- 1 cup of soy milk
- ½ cup of tofu or tempeh
- Do not over-depend on refined soy products that contain concentrated isoflavones.
Combining Soy Foods with Thyroid Treatment
To minimise risks and maximise benefits:
- Pairing: Soy foods should be taken together with iodine-containing foods such as fish, seaweed, or iodised salt.
- Timing: One should not eat soy products around the time of taking their medications.
- Diversity: You should also add other types of plant protein sources, like lentils and chickpeas, to your diet.
Conclusion
Soybeans have all the necessary amino acids, making them an excellent alternative to animal protein. While it is an excellent food option, its iodine absorption capabilities make it a cautious choice for those with thyroid disorders.
Having said that, the additional benefits of soybeans make it a great dietary choice for those battling thyroid disorders. However, such individuals need to ensure they are consuming it in moderate amounts and that it is not interfering with their medications. So, keep these details in mind and use soybeans to create a balanced and nutritious diet.
Consult Top Endocrinologists
Consult Top Endocrinologists
Dr. Nithin Reddy Modhugu
Endocrinologist
6 Years • MBBS, MD (General Medicine), DNB (Endocrinology)
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Dr. Nithin's Endocrine Clinic, Hyderabad
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Dr. Gayatri S
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8 Years • MBBS,MD( GEN MEDICINE), DM ( ENDOCRINOLOGY)
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Sanjeevani Hospital, Krishna district
Dr. Arunava Ghosh
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Kolkata
VDC Clinic, Kolkata
