Is Rice Healthier After Being Refrigerated? Understanding Resistant Starch

November 22, 2025 •

3 min read

According to a 2015 study, cooked rice that was cooled for 24 hours at 4°C and then reheated had 2.5 times as much resistant starch as freshly cooked rice. This surprising fact points to the growing body of evidence suggesting that cooling rice in the refrigerator might actually improve its nutritional profile, particularly in relation to resistant starch.

Quick Summary

Cooling cooked rice transforms some digestible starches into resistant starch through a process called retrogradation, which may offer health benefits. This resistant starch acts like fiber, supporting gut health, potentially aiding weight management, and helping to regulate blood sugar levels. Proper food safety procedures are crucial to prevent bacterial growth.

Key Points

Resistant Starch: Refrigerating cooked rice creates resistant starch (RS) through a process called retrogradation, making it harder for your body to digest.
Lower Glycemic Index: The higher RS content in cooled rice results in a lower glycemic index, causing a smaller and slower blood sugar spike.
Improved Gut Health: Resistant starch acts as a prebiotic, feeding beneficial gut bacteria and promoting the production of short-chain fatty acids.
Weight Management: Due to its slower digestion, refrigerated rice may contribute to a greater feeling of fullness and fewer absorbed calories.
Food Safety is Crucial: Improper cooling of cooked rice can lead to the growth of Bacillus cereus bacteria, which can cause food poisoning.
Proper Cooling Technique: To be safe, cool cooked rice within one hour by placing it in shallow containers in the refrigerator.
Reheating Maintains Benefits: Reheating cooled rice does not eliminate the resistant starch, allowing you to enjoy the benefits with warm food.
Beneficial for Diabetics: Individuals with diabetes or insulin resistance may find cooled rice a better dietary option for managing blood glucose levels.

The Science of Resistant Starch and Rice

When rice is freshly cooked, its starch is easily digested and absorbed, leading to a rise in blood glucose levels. However, refrigerating cooked rice initiates starch retrogradation. During this process, starch molecules restructure into resistant starch (RS), which isn't digested in the small intestine and acts like a prebiotic in the large intestine, feeding beneficial gut bacteria.

Resistant Starch and Blood Sugar Control

Resistant starch contributes to a lower glycemic response as it doesn't cause a rapid glucose spike like digestible starches. Consuming cooked and cooled rice can lead to a slower, more stable rise in blood sugar, potentially benefiting individuals managing blood glucose.

The Impact on Gut Health and Digestion

Fermentation of resistant starch by gut bacteria produces short-chain fatty acids (SCFAs) like butyrate. SCFAs nourish colon cells, support a healthy gut barrier, and may reduce inflammation. A gut microbiome supported by prebiotics like resistant starch is associated with better digestive health and potentially increased feelings of fullness, which could aid in weight management.

Important Food Safety Precautions

Proper food safety is crucial with cooked rice to prevent the growth of Bacillus cereus, bacteria whose spores can survive cooking. If rice cools slowly at room temperature, these spores can multiply and produce toxins causing food poisoning.

To minimize risk:

Cool rice rapidly within one hour of cooking.
Store in shallow, airtight containers in the refrigerator.
Avoid leaving cooked rice at room temperature for long periods.
Consume refrigerated rice within 24 hours.
If reheating, ensure it's steaming hot throughout (at least 165°F).

Comparison of Freshly Cooked vs. Refrigerated Rice


Feature	Freshly Cooked Rice	Refrigerated Rice (Cooled 12-24 hrs)
Starch Type	Primarily digestible starch	Higher percentage of resistant starch
Glycemic Index (GI)	Higher	Lower
Blood Sugar Impact	Can cause rapid blood sugar spikes	Causes a slower, more stable rise in blood sugar
Gut Health	Less benefit; starch is digested early	Acts as a prebiotic, feeding good gut bacteria
Digestion Speed	Rapid digestion and absorption	Slower digestion; acts more like fiber
Calorie Content	Higher number of absorbed calories	Fewer absorbed calories due to undigested starch
Preparation	Eaten immediately after cooking	Requires extra step of cooling in refrigerator

Versatility and How to Incorporate Refrigerated Rice

Refrigerated rice is versatile and can be used in various dishes. Prepare a large batch for meal prep and use it throughout the week in fried rice, salads, or reheated side dishes. Light reheating helps preserve the resistant starch.

Creative Ways to Use Cooled Rice

Fried Rice: Use cold rice for better texture.
Salads: Add cooled rice to grain bowls or salads for extra resistant starch.
Stuffed Vegetables: Mix with other ingredients to stuff vegetables.
Cold Rice Pudding: Create a lower-glycemic dessert.

The Final Verdict

Refrigerating rice offers nutritional advantages by increasing resistant starch, which benefits blood sugar control and gut health. However, strict adherence to food safety guidelines for rapid cooling and storage is essential to prevent food poisoning from Bacillus cereus. By following these practices, you can safely enjoy the health benefits of cooled rice.

For more in-depth nutritional information on resistant starch and its benefits, explore resources such as the CSIRO's information page on the topic(https://www.csiro.au/en/research/health-medical/nutrition/Resistant-starch).

Frequently Asked Questions

No, reheating refrigerated rice does not reverse the formation of resistant starch. Once the starch retrogrades during cooling, its structure is largely stable, and the health benefits are maintained even after the rice is reheated.

For optimal safety, cooked rice should be stored in the refrigerator for no more than 24 hours before consumption. After cooking, it must be cooled rapidly within one hour before refrigerating.

The bacterium associated with food poisoning from improperly stored rice is Bacillus cereus. Its spores can survive cooking and multiply rapidly if the rice is left to cool slowly at room temperature.

The formation of resistant starch through cooling applies to all starchy foods, including different types of rice. The exact amount of resistant starch formed can vary depending on the rice variety and amylose content.

For some individuals, especially those with irritable bowel syndrome (IBS), a sudden increase in resistant starch can cause mild side effects like gas and bloating, as the gut bacteria ferment the undigested starch.

Some studies suggest that adding a small amount of oil to rice while cooking and then cooling it can further increase the resistant starch content by forming starch-lipid complexes, but cooling is the primary driver of retrogradation.

Yes, it is safe to eat rice cold directly from the refrigerator, provided it has been cooked, cooled, and stored properly and consumed within 24 hours. Many people use it for salads and other cold dishes.