What Foods Should You Avoid If You Have Beriberi?

November 19, 2025 •

3 min read

According to the National Institutes of Health, beriberi is most common in areas where the diet includes unenriched, processed white rice, which has a drastically reduced thiamine content. To effectively manage this condition, it is critical to know what foods you should avoid if you have beriberi and focus on a thiamine-rich diet instead.

Quick Summary

This guide outlines the key dietary restrictions for managing beriberi, a vitamin B1 deficiency. It details specific foods to eliminate or limit, such as refined carbohydrates, alcohol, and raw seafood, to help improve thiamine levels and aid recovery.

Key Points

Refined Grains: Polished white rice and white flour products are stripped of thiamine during processing and should be avoided or replaced with whole-grain alternatives.
Alcoholic Beverages: Excessive alcohol consumption interferes with thiamine absorption and storage, making it a critical item to avoid for recovery.
Raw Fish and Shellfish: These contain thiaminase enzymes that destroy thiamine; they should be cooked thoroughly or excluded from the diet.
Excessive Tea and Coffee: Certain compounds in these drinks can hinder thiamine absorption, so moderation is advised.
Processed Carbs and Sugars: High-sugar items and highly processed carbohydrates deplete thiamine and should be significantly reduced.
Cassava: A diet heavily based on cassava can create a net thiamine deficit and should be avoided.

Beriberi, a condition resulting from a severe deficiency of vitamin B1 (thiamine), is most often caused by a poor diet. While supplements are typically prescribed for treatment, dietary changes are paramount for preventing recurrence and supporting overall health. A successful recovery plan involves not only adding thiamine-rich foods but also eliminating those that deplete or inhibit the body's absorption of this vital nutrient.

Refined Grains and High-Sugar Foods

Highly refined and processed carbohydrates are a major contributor to thiamine deficiency because the milling process removes the thiamine-rich outer layers of the grain. The body uses thiamine to metabolize carbohydrates, so consuming high amounts of low-thiamine carbs creates a further deficiency.

Polished White Rice

Polished white rice is famously associated with beriberi, particularly in regions where it is a dietary staple. The process of milling removes the rice germ and husk, where the majority of thiamine resides. Switching to brown rice or other whole grains is a crucial step for individuals with beriberi.

White Flour and Sugar

Similar to white rice, white flour and products made from it (like white bread and pastries) have most of their thiamine stripped during processing. These, along with excessive amounts of refined sugar, should be minimized or eliminated.

Alcohol and Its Impact

Excessive alcohol consumption is a significant risk factor for thiamine deficiency, particularly in developed countries. Alcohol interferes with the absorption and utilization of thiamine in several ways:

It reduces the body's ability to absorb thiamine from the gastrointestinal tract.
It can damage the liver, which plays a key role in storing thiamine.
Heavy alcohol use often leads to poor dietary habits, further reducing nutrient intake.

For those recovering from beriberi, especially alcohol-related forms like Wernicke-Korsakoff syndrome, abstinence from alcohol is essential.

Foods Containing Thiaminase Enzymes

Certain raw foods contain enzymes called thiaminases, which break down and destroy thiamine. Cooking typically deactivates these enzymes, but raw consumption can be problematic for those with or at risk of thiamine deficiency.

Raw Fish and Shellfish

Raw freshwater fish and shellfish, including shrimp, mussels, and clams, are known to contain thiaminases. While cooking these items neutralizes the enzyme, consuming them raw can exacerbate a deficiency. This is particularly relevant in areas where uncooked fish is a traditional part of the diet.

Ferns

Some varieties of ferns, which are consumed in certain cultures, also contain thiaminase enzymes.

Beverages High in Anti-Thiamine Factors

Certain beverages contain compounds, such as tannins, that can interfere with thiamine absorption.

Tea and Coffee

Excessive consumption of tea and coffee, both of which contain anti-thiamine factors, should be moderated. While the impact is generally small for most people, it can be a contributing factor in those already at risk.

Other Thiamine-Depleting Foods

Cassava: Although it contains some thiamine, a diet heavily reliant on cassava can lead to a net thiamine deficit, as the high carbohydrate load requires more thiamine to metabolize than the food provides.
Sulfite-Rich Foods: Processed foods that use high levels of sulfites as a preservative can destroy thiamine content. Limiting processed items is generally beneficial for thiamine levels.

Creating a Thiamine-Friendly Diet

Transitioning away from thiamine-depleting foods is crucial. To rebuild thiamine stores, focus on incorporating a wide variety of nutrient-dense, thiamine-rich alternatives.

Excellent sources of thiamine include:

Whole Grains: Brown rice, whole wheat bread, oats, and fortified cereals.
Legumes: Lentils, soybeans, and beans.
Pork: A particularly good source of thiamine.
Nuts and Seeds: Especially sunflower seeds.
Vegetables: Green leafy vegetables, beets, and potatoes.
Fish: Cooked fish and other seafood are safe and healthy options.

Comparing Food Choices


Food Type	Poor Thiamine Source (Avoid)	Excellent Thiamine Source (Choose)
Grains	Polished white rice, white bread	Brown rice, fortified cereals, whole wheat bread
Protein	Raw freshwater fish, raw shellfish	Cooked fish, pork, legumes
Beverages	Excessive alcohol, strong black tea/coffee	Water, fruit juices (e.g., orange)
Processed Items	High-sugar foods, sulfite-preserved foods	Whole foods, nuts, seeds

Conclusion

Effectively managing beriberi requires a comprehensive approach that targets both dietary deficiencies and inhibitors. By actively avoiding polished rice, excessive alcohol, and raw thiaminase-containing foods, and by prioritizing a diet rich in whole grains, legumes, and lean protein, individuals can significantly support their thiamine recovery. Consultation with a healthcare provider is essential for a personalized treatment plan, which may include thiamine supplementation. A balanced diet, however, remains the cornerstone of long-term prevention and wellness for anyone affected by beriberi.

Visit MedlinePlus for more information on Beriberi and its causes

Frequently Asked Questions

Polished white rice is harmful because the milling process removes the germ and husk, which contain most of the grain's thiamine (vitamin B1). As a result, it provides minimal thiamine while its high carbohydrate content increases the body's thiamine requirement for metabolism.

You should limit your intake of coffee if you have a thiamine deficiency. Coffee contains anti-thiamine factors, such as tannins, that can interfere with thiamine absorption, especially when consumed in large amounts.

Eating raw fish can worsen a thiamine deficiency because certain raw seafood contains thiaminase enzymes. These enzymes actively destroy thiamine in the body, which can be detrimental to recovery.

Alcohol negatively impacts thiamine levels by reducing the body's ability to absorb the vitamin and by hindering its storage in the liver. This effect makes alcohol consumption a major risk factor for beriberi.

Certain types of raw ferns are known to contain thiaminase enzymes, which destroy thiamine. While most common vegetables are beneficial, it is wise to avoid raw ferns.

For beriberi recovery, brown rice or other whole-grain rice varieties are the best choice. Unlike polished white rice, they retain their thiamine-rich outer layers and nutrients.

Yes, cooking shellfish like shrimp or clams deactivates the thiaminase enzymes they contain, making them a safe and nutritious part of a balanced diet for beriberi recovery.

You should avoid highly refined carbohydrates like white sugar and white flour, but not all carbs. Complex carbohydrates from whole grains, legumes, and certain vegetables are essential and provide important thiamine.