What are the disadvantages of eating millet? Weighing the pros and cons

November 11, 2025 •

5 min read

While millets have been hailed as a nutritional powerhouse, a 2024 review in Frontiers in Sustainable Food Systems noted that antinutritional factors can hinder nutrient absorption, a key disadvantage of eating millet if not prepared properly. This highlights that like any food, millets have a nuanced profile that requires careful consideration for optimal health.

Quick Summary

Millets contain antinutrients that can inhibit mineral absorption, potential goitrogens affecting thyroid health, and high fiber that may cause digestive issues for some individuals. These drawbacks are primarily associated with excessive intake, especially in susceptible people or those with existing conditions.

Key Points

Antinutrients hinder mineral absorption: Compounds like phytates and tannins in millets can reduce the bioavailability of essential minerals such as iron, zinc, and calcium.
Goitrogens may affect thyroid function: Excessive consumption of millets, especially pearl millet, can interfere with iodine uptake by the thyroid, particularly for individuals with pre-existing thyroid conditions or in iodine-deficient areas.
High fiber can cause digestive discomfort: The high fiber content of millets may lead to bloating, gas, and cramps for some people, especially when introduced rapidly into the diet.
Proper preparation can reduce negative effects: Soaking, sprouting, or fermenting millets before cooking can significantly decrease antinutrient levels and improve digestibility.
Risks are generally tied to excessive intake: Most disadvantages are associated with consuming very large quantities of millet, especially in unprepared forms or as a sole staple, rather than moderate inclusion in a balanced diet.
Individual health context matters: People with sensitive digestive systems, thyroid disorders, or specific allergies should be more cautious with millet intake and consider professional medical advice.

Millets, a group of ancient, small-seeded grains, have garnered significant attention in recent years for their nutritional benefits, gluten-free nature, and resilience as a crop. However, as with any food, a balanced perspective is essential, and it's important to understand the potential drawbacks, particularly associated with excessive consumption or improper preparation. Addressing the question of what are the disadvantages of eating millet? reveals a few key areas of concern related to antinutrients, thyroid function, and digestive health.

The Impact of Antinutrients on Mineral Absorption

Antinutrients are natural compounds found in many plant-based foods, including millets, that can interfere with the body's ability to absorb essential minerals. The most prominent antinutrients in millets include phytates, tannins, and oxalates.

How antinutrients affect the body

Phytates: Phytic acid, or phytate, is a primary storage form of phosphorus in many seeds and grains. It has a strong chelating ability, meaning it binds to minerals like iron, zinc, and calcium, forming insoluble complexes that the body cannot easily absorb. This can be a concern for people who consume a millet-heavy diet, especially in regions where malnutrition is already an issue. Research indicates that the high phytate content in certain millets could be a health risk, particularly for tribal communities and poor farmers who depend on it as a primary staple.
Tannins: These polyphenolic compounds can reduce the bioavailability of minerals, especially iron. High levels of tannins can also interfere with protein digestion. Darker-colored millets often contain higher concentrations of tannins.
Oxalates: Found in foxtail millet, oxalates can bind with calcium and potentially contribute to the formation of kidney stones in susceptible individuals.

Goitrogens and Thyroid Health Concerns

One of the most frequently discussed disadvantages of millets is their goitrogenic effect, which can interfere with thyroid function. Millets contain compounds known as goitrogens, specifically C-glycosylflavones like vitexin and glucosylvitexin, which can inhibit iodine uptake by the thyroid gland and disrupt thyroid hormone synthesis.

Factors influencing goitrogenic effects

Excessive consumption: The goitrogenic effect is most notable with excessive, long-term consumption of millet as a staple food, especially in iodine-deficient populations. A study in Western Sudan, for instance, linked high millet intake in an iodine-deficient region to a greater prevalence of goiter.
Individual differences: Not all individuals will be equally affected. People with pre-existing thyroid conditions, such as hypothyroidism, are more sensitive to the goitrogenic compounds and should monitor their intake.
Processing: While cooking can reduce the goitrogenic effect of some foods, some studies suggest that the effect in millets may not be completely eliminated by heat and can even increase with certain processing methods.

Digestive Challenges and Allergies

Although millets are rich in beneficial fiber, this can present a challenge for some digestive systems, particularly when intake is suddenly increased.

Common digestive issues

Gas and Bloating: The high fiber content can lead to gas and bloating as the gut bacteria work to digest it. For those unaccustomed to high-fiber diets, a gradual introduction is recommended.
Delayed Digestion: The slow digestibility of millet's high fiber content can cause some individuals to experience a feeling of fullness for a longer period, which can be a pro for weight management but a con for those with sensitive digestive tracts.

Allergic potential

While less common than allergies to grains like wheat, millet allergy is possible. Symptoms can include digestive upset, skin rashes, and respiratory issues. Individuals with existing grain allergies should be cautious. For those with celiac disease, although millet is naturally gluten-free, it is crucial to ensure it is certified gluten-free to avoid cross-contamination from processing facilities that handle other grains.

Strategies to Mitigate the Disadvantages

Fortunately, many of the drawbacks associated with millets can be minimized or eliminated with proper preparation.

Reducing antinutrients and enhancing digestion

Soaking: Soaking millets overnight activates the phytase enzyme, which helps break down phytic acid and improves mineral bioavailability. It also softens the grains, aiding digestion.
Germination (Sprouting): Sprouting is a highly effective way to reduce antinutrients like phytates and tannins. It also enhances the nutritional profile, increasing enzyme activity and making nutrients more bioavailable.
Fermentation: Fermenting millets into batters for dishes like dosas or idlis significantly reduces antinutrient content and enhances protein and mineral availability.
Thorough Cooking: Thoroughly cooking millets helps to further break down some of the less-desirable compounds and improves digestibility.

Navigating Millet Consumption: Summary and Conclusion

Millets are a nutritional powerhouse, offering fiber, protein, and a range of vitamins and minerals. Their low glycemic index and gluten-free status make them an excellent choice for many individuals. However, the potential disadvantages of eating millet, including the presence of antinutrients that inhibit mineral absorption, goitrogens that can affect thyroid function in excessive amounts, and high fiber that can cause digestive issues, require mindful consumption and preparation.

For most people who consume millets in moderation as part of a varied diet, these risks are minimal. The key lies in traditional preparation methods like soaking, sprouting, and fermenting, which effectively reduce the antinutrient load. Individuals with specific health concerns, particularly thyroid disorders or sensitive digestive systems, should pay closer attention to portion sizes and preparation, and consult a healthcare professional for personalized advice. By understanding these nuances, you can enjoy the many benefits of millets while minimizing any potential drawbacks. For more detailed information on nutrient bioavailability, you can consult research articles on reputable sites such as the National Institutes of Health (NIH) website.

Comparison: Effects of Millet on Individuals with and without Health Concerns


Aspect	General Population (Balanced Diet)	Individuals with Health Concerns (e.g., Hypothyroidism, IBS)
Antinutrients	Minimal impact on mineral absorption due to variety in diet.	Potential for mineral deficiencies if relying heavily on millets without proper preparation.
Thyroid Function	Risks from goitrogens are negligible when millets are consumed moderately and iodine intake is adequate.	Increased risk of interfering with thyroid hormone production and iodine uptake; requires caution and professional medical advice.
Digestive System	High fiber content can aid digestion and gut health; potential for temporary gas/bloating when first introduced.	May experience significant discomfort, gas, or bloating; need to introduce millets slowly and utilize preparation methods that aid digestion.
Allergic Potential	Very low risk of allergic reaction, as millet is not a major allergen.	Higher susceptibility to allergies; should be cautious and monitor body's response.

Frequently Asked Questions

Yes, millets contain goitrogens, and excessive consumption, particularly of pearl millet, has been linked to interfering with thyroid function, especially in individuals with iodine deficiency. People with hypothyroidism should be particularly cautious.

Due to its high fiber content, millet can cause digestive issues such as gas, bloating, and discomfort in some people, especially those with sensitive digestive systems or when large amounts are introduced too quickly.

You can reduce antinutrients like phytates and tannins by soaking, sprouting, or fermenting millets before cooking. Soaking overnight, for instance, can significantly lower the phytic acid content.

Millet is generally safe for most people when consumed in moderation. However, individuals with thyroid disorders, sensitive digestive systems, or a rare millet allergy should be cautious.

Yes, millets contain antinutrients that can bind to minerals like iron, zinc, and calcium, hindering their absorption. This effect can be minimized with proper processing and a varied diet.

The primary risks of eating too much millet include potential interference with thyroid function due to goitrogens and reduced mineral absorption due to high levels of antinutrients. These issues are more pronounced with excessive, long-term intake.

Some types of millets, like foxtail millet, contain oxalates. In individuals prone to kidney stones, particularly calcium oxalate stones, limiting intake might be advised. Always consult a healthcare provider for personalized guidance.