Shiitake Mushroom Glycemic Index
Shiitake mushrooms are low-calorie, low-carb mushrooms with a very low GI and virtually zero glycemic load, making them safe and useful for blood sugar management.
Back to GI ChartOverview
Shiitake mushrooms are an edible fungus native to East Asia that are now used worldwide in stir-fries, soups, sauces, and meatless main dishes. They have a naturally low glycemic index of around 15, similar to other mushrooms, because they contain very little digestible carbohydrate and are mostly water and fiber. A typical serving provides so few carbs that the glycemic load is essentially zero, meaning shiitakes do not raise blood sugar in any meaningful way. Instead, they contribute savory umami flavor and small amounts of fiber, B vitamins, and minerals while adding minimal calories. Shiitakes are also notable for unique bioactive compounds such as beta-glucans and lentinan, which are being studied for potential immune and cholesterol benefits. For people with diabetes, prediabetes, or insulin resistance, shiitake mushrooms are an easy way to bulk up meals, replace some meat, and add depth of flavor without adding glycemic load.
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Nutrition Facts for Shiitake Mushroom
Per serving: 1 cup (145g)
Macronutrients
Expanded Analysis
Digestion Rate
Because shiitake mushrooms are low in starch and high in water and fiber, there is very little carbohydrate available to be digested into glucose. Most of the small amount of natural sugar is embedded in a fibrous matrix, and when shiitakes are cooked they maintain a chewy texture that slows how quickly any carbohydrate is absorbed. When eaten in realistic portions, their impact on the blood glucose curve is negligible.
Satiety Effects
Shiitake mushrooms are not particularly energy dense or protein rich, but they can still contribute to satiety by adding bulk, texture, and savory flavor to meals. Using shiitakes to replace some refined starches or to extend meat in stir-fries, stews, or pasta dishes increases the volume of food without adding many calories or carbohydrates. This can help people feel fuller on fewer carbs and support better portion control.
Energy Density
At roughly 34 calories per cup cooked, shiitake mushrooms are a very low-energy-density food. Most of their weight is water, with modest amounts of fiber, protein, and minimal fat. For individuals working on weight and blood sugar management, swapping some high-calorie, high-carb ingredients with shiitakes can lower the overall calorie and carbohydrate load of the meal while keeping it satisfying.
Traffic Light Summary
Better Blood Sugar Management for Shiitake Mushroom Lovers
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The Science Behind the Glycemic Index
How GI Was Measured
GI values for mushrooms are determined using the same standardized method as other foods: volunteers consume a portion that provides 50 g of available carbohydrate, and their blood glucose response over two hours is compared with the response to pure glucose. Because mushrooms contain so little carbohydrate, reaching 50 g of available carbs would require eating an unrealistically large amount, so published GI values are often extrapolated or based on smaller portions combined with carbohydrate-rich test meals.
Why This Food Has This GI
Shiitake mushrooms have a very low GI largely because they provide minimal digestible carbohydrate and significant water and fiber relative to their weight. The limited starch and natural sugars they contain are absorbed slowly from the digestive tract, and the total amount is too small to produce a notable glucose spike. Added oils, sauces, and other ingredients in mushroom dishes usually have a bigger influence on blood sugar than the mushrooms themselves.
Factors Affecting GI
- Cooking method: pan-searing or roasting with oil does not significantly change GI because the carbohydrate content remains very low.
- Food combinations and portion size: the glycemic impact of a shiitake-containing meal is usually dominated by the starches or sugars served alongside, such as rice or noodles, and even generous mushroom portions contribute very little additional carbohydrate.
- Added sauces: sweet glazes or sugary stir-fry sauces can raise the GI and GL of the overall dish much more than the mushrooms themselves.
Blood Sugar Impact
Short-Term Effects
Shiitake mushrooms have essentially no short-term effect on blood sugar when eaten in typical amounts. Their carbohydrate content is very low, and what little carbohydrate they contain is diluted within a high-water, high-fiber matrix. When shiitakes are included in stir-fries, soups, or grain bowls, any observed blood glucose rise is almost entirely due to the rice, noodles, or other starches they accompany. For someone monitoring glucose closely, shiitake mushrooms can be considered a very safe ingredient that does not need to be ‘budgeted’ like bread, pasta, or sweets. Even fairly large portions mainly change the volume and fiber content of the meal rather than the glucose curve, so most people do not need to count them toward carbohydrate limits except in very precise clinical situations.
Long-Term Effects
Over time, regularly using shiitake mushrooms to replace more energy-dense and carbohydrate-heavy ingredients can support better weight management and overall metabolic health. Some research suggests that mushroom consumption, including shiitakes, may be associated with improved lipid profiles and markers of inflammation, factors that are important in diabetes and cardiovascular risk. While shiitakes themselves do not directly lower HbA1c, their role in creating lower-calorie, lower-carb meals can contribute to better glycemic control as part of an overall pattern.
Insulin Response
Because shiitakes contain very little carbohydrate, they provoke only a minimal insulin response. The protein and small amount of carbohydrate are handled easily by the body without demanding large insulin surges. In mixed meals, the insulin needed is driven by accompanying carbohydrate sources; shiitakes neither significantly increase nor decrease this requirement on their own.
Second Meal Effect
Shiitakes have not been specifically studied for a second-meal effect. However, their ability to bulk up dishes without adding many carbs can help reduce reliance on refined starches across the day, which may indirectly support more stable glucose and insulin patterns between meals. When shiitakes are used to create more filling, vegetable-focused lunches and dinners, some people notice fewer late-evening cravings and less snacking on high-GI foods, which further supports smoother glucose profiles from one meal to the next.
Health Benefits
Shiitake mushrooms offer a mix of culinary and potential health benefits for people with and without diabetes. They deliver deep umami flavor that can reduce the need for added salt and rich sauces, helping make lower-calorie meals more satisfying. Nutritionally, they provide small amounts of fiber, B vitamins, copper, and selenium in a very low-calorie package. Shiitakes also contain beta-glucans and other polysaccharides that have been studied for their immune-modulating and cholesterol-lowering effects. While many of these findings come from concentrated extracts or animal research, including shiitakes in an overall vegetable-rich eating pattern aligns well with dietary recommendations for metabolic and heart health.
Zero glycemic load
Shiitake mushrooms provide so little digestible carbohydrate per serving that their calculated glycemic load is effectively zero, meaning they do not significantly affect blood sugar levels even when eaten in generous portions alongside other foods.
View StudyContains beta-glucans
Shiitakes contain beta-glucan fibers similar to those found in oats and barley, which have been linked to improved cholesterol levels and potential immune benefits in experimental studies.
View StudyMay support immunity
Compounds such as lentinan isolated from shiitake mushrooms have been investigated as immune-modulating agents and adjunctive cancer therapies in some countries, suggesting a broader immune-supporting role that goes beyond basic nutrition and may influence inflammatory pathways.
View StudyHelps replace higher-calorie ingredients
Using shiitakes to replace portions of meat or refined starches in recipes can lower calorie density and saturated fat intake without sacrificing flavor, supporting weight and cardiovascular risk management.
View StudyRisks & Precautions
Allergies
Although relatively uncommon, mushroom allergies can occur and may cause symptoms ranging from mild itching to severe reactions. Anyone with a known mushroom allergy should avoid shiitake mushrooms.
Overconsumption
Eating very large amounts of shiitake mushrooms, especially raw or undercooked, has been associated with a rare condition called shiitake dermatitis, a line-shaped rash likely related to a compound called lentinan.
Medication Interactions
There are no well-documented direct drug interactions with shiitake mushrooms when consumed as food. People using immunosuppressive therapy should speak with their physician before taking concentrated shiitake supplements.
Toxicity Warnings
Shiitake mushrooms should be stored in the refrigerator and cooked thoroughly to minimize microbial contamination and foodborne illness risk. Foraged mushrooms should never be eaten unless positively identified by an expert, since toxic look-alike species can cause severe poisoning. People who develop a rash or unusual symptoms after eating shiitakes should seek medical advice and avoid further exposure until evaluated.
Special Populations
Pregnancy
Cooked shiitake mushrooms are generally considered safe during pregnancy as part of a balanced diet. Raw or undercooked mushrooms are best avoided for food safety reasons.
Kidney Issues
Shiitakes contain moderate amounts of potassium and phosphorus. People with advanced kidney disease on restricted diets should account for mushroom intake in their overall potassium and phosphorus budget.
Heart Conditions
Shiitakes can support heart-healthy eating patterns when used to reduce sodium- and fat-heavy ingredients. High-sodium sauces in some mushroom dishes may not be suitable for those with heart failure or uncontrolled hypertension.
Who Should Limit It
Individuals with mushroom allergies, those who have previously experienced shiitake dermatitis, and people with strict potassium or phosphorus limits may need to limit or avoid shiitake mushrooms. Anyone on immunosuppressive therapy or with complex medical conditions should also discuss heavy use of mushroom supplements with their healthcare team rather than self-prescribing concentrated extracts.
Portion Guidance
Recommended Serving
A common serving is about 1 cup cooked shiitake mushrooms (around 145g), which has essentially zero glycemic load and can be counted as a non-starchy vegetable.
Portion Scaling & Glycemic Load
- 50g cooked shiitake mushroomsGL: 0
- 145g cooked shiitake mushrooms (1 cup)GL: 0
- 250g cooked shiitake mushroomsGL: 0
Visual Examples
- A generous layer of sliced shiitakes covering a dinner plate portion of stir-fry
- A full soup bowl of broth loaded with shiitake slices and vegetables
- Roughly the volume of a large fist when sautéed and piled on a plate
Frequency of Consumption
Shiitake mushrooms can be included several times per week as part of mixed dishes or sides without concern for raising blood sugar.
Impact of Preparation
Raw
Raw shiitake mushrooms are rarely eaten and can be tough and less digestible; cooking improves texture and safety by softening the cell walls and reducing the risk of gastrointestinal upset. Lightly cooking also helps develop flavor so that smaller portions feel satisfying.
Cooked
Sautéing or simmering shiitakes in soups and stews softens their texture and rounds out flavor without adding carbohydrates. Their GI and GL remain effectively zero, so the main glycemic impact still comes from whatever starches are cooked alongside them.
Roasted
Roasting shiitakes at high heat concentrates flavor and slightly reduces moisture but does not change their negligible carbohydrate content. The intense roasted taste can make vegetable-forward dishes more appealing, which is useful when trying to shift away from heavy, starch-based meals.
Fried
Deep-frying shiitakes or preparing them in tempura batter adds fat and refined carbohydrates from the batter, which can increase calorie density and glycemic impact of the overall dish. For people with diabetes and cardiovascular risk factors, these richer preparations are best saved for special occasions in small portions.
Boiled
Boiling shiitakes in soups or broths leaches some water-soluble nutrients into the liquid, which is usually eaten as part of the meal and keeps the overall glycemic load very low.
Processed
Dried shiitakes are commonly used in Asian cooking; once rehydrated and cooked, their nutritional profile is similar per gram of dry weight. Their carb content still remains low at typical serving sizes, and they are convenient to keep on hand for quick, diabetes-friendly meals. Because they store well and add intense flavor, they make it easier to prepare lower-calorie, vegetable-forward dishes instead of relying on refined starches or heavy sauces.
Storage Effect on GI
Refrigeration and reheating of cooked shiitakes do not meaningfully alter their GI or GL because the carbohydrate fraction is so small. The main considerations are food safety, flavor, and texture when using leftovers in soups, stir-fries, or grain bowls.
Cooking Effect on Nutrients
Cooking slightly reduces some heat-sensitive vitamins but can make certain beneficial compounds more bioavailable. Using minimal added salt and oil preserves their health benefits in diabetes-friendly meals, and pairing them with other vegetables increases the overall micronutrient density of the plate.
Usage Guidance
For Blood Sugar Management
Optimal Pairings
- Stir-fries that combine shiitakes with non-starchy vegetables and a lean protein
- Soups and broths where shiitakes replace some noodles or rice
- Grain bowls where shiitakes provide volume so portions of rice or noodles can be smaller
- Omelets or egg scrambles loaded with shiitakes and greens instead of breakfast potatoes or large pieces of toast
Using shiitake mushrooms to bulk up dishes allows you to reduce portions of higher-GI starches without making the meal feel smaller. This lowers the overall glycemic load of the meal and helps keep post-meal glucose levels steadier. Because shiitakes add umami and texture, they make vegetable-forward plates more satisfying, which can make it easier to stick with lower-carb choices over time.
Meal Timing Tips
Shiitake-containing dishes can be eaten at any meal. Many people with diabetes find them especially helpful at lunch and dinner in place of some starch, which can improve later post-meal and overnight blood sugars. Including them in evening meals that are lighter on refined carbohydrates may also reduce late-night snacking driven by hunger or cravings.
Best Ways to Reduce GI Impact
- Use shiitakes in place of some noodles or rice in stir-fries and soups.
- Pair shiitakes with lean protein and plenty of other non-starchy vegetables.
- Avoid heavy, sugary sauces when cooking dishes that include shiitakes.
- Use dried shiitakes for intense flavor to make vegetable-based dishes more satisfying.
Culinary Uses
Common Uses
Shiitake mushrooms are widely used in Asian cuisines in stir-fries, soups, noodle dishes, braises, and vegetarian mains, and they also work well in modern fusion recipes like grain bowls and lettuce wraps.
Simple Preparation Ideas
- Sauté sliced shiitakes with garlic and a splash of low-sodium soy sauce.
- Add rehydrated dried shiitakes to chicken or vegetable broth for extra umami.
- Roast shiitake caps with olive oil and herbs as a side dish.
- Mix finely chopped shiitakes into lean ground meat or bean patties to boost flavor while stretching portions.
Recipe Ideas
- Stir-Fried Shiitake Mushrooms with Bok Choy and Tofu
- Miso Soup with Shiitake Mushrooms and Greens
- Garlic-Roasted Shiitake Mushrooms over Cauliflower Rice
Substitution Tips
Use shiitakes instead of some meat in stir-fries to lower calories and saturated fat while keeping rich flavor. Substitute them for part of the noodles or rice in bowls to reduce carbohydrate load, or swap them in for high-calorie toppings like bacon bits on salads and baked potatoes.
Diet Suitability
Diabetes
Highly suitable as a non-starchy, low-carb vegetable that can be used liberally in meals to increase volume without raising blood sugar.
Keto
Very suitable for ketogenic diets because they are low in net carbs and can replace higher-carb ingredients in stir-fries, omelets, and soups.
Low-Carb
Excellent fit for low-carb diets as a way to add volume and flavor without adding carbohydrates, making plates look and feel more substantial.
Low-GI
Perfect for low-GI eating patterns because they have a very low GI and negligible GL, especially when paired with other low-GI foods.
Weight Loss
Helpful for weight-loss diets by increasing meal volume for very few calories when used to replace denser foods, supporting portion control, satisfaction, and gradual reductions in refined carbohydrates.
Heart-Healthy
Support heart-healthy patterns by helping reduce reliance on high-sodium meats or rich sauces when used creatively in stews, stir-fries, and pasta dishes.
Plant-Based
A valuable ingredient in vegetarian and vegan diets, adding savory flavor and texture to plant-based dishes and helping replace some processed meat substitutes.
Food Comparisons
Alternatives & Substitutions
Lower GI Alternatives
- Other low-GI mushrooms such as white or portobello mushrooms
- Non-starchy vegetables like broccoli or zucchini used in similar dishes
- Leafy greens such as spinach or kale that can take on similar flavors in stir-fries and soups
Foods Replaced by This
- Replacing part of the rice or noodles in stir-fries with extra shiitake mushrooms
- Using shiitakes instead of bread or crackers as a topping base in some recipes
- Swapping mushroom-heavy vegetable sautés for creamy pasta side dishes
- Using shiitakes in place of sugary, starchy casserole toppings to keep carbohydrate load lower
Budget-Friendly Options
- Dried shiitake mushrooms bought in bulk and rehydrated at home
- Switching between shiitakes and less expensive white mushrooms in mixed dishes
- Buying frozen mixed vegetables that include mushrooms when fresh options are expensive
Allergy-Safe Alternatives
- Other non-fungal vegetables like eggplant or zucchini for people with mushroom allergies
- Tofu or tempeh for plant-based protein and texture if mushrooms are not tolerated
- Legume-based dishes such as lentil stews or chickpea sautés that provide chew and protein without fungi
Research Library
Health-Promoting Properties of Mushrooms
Review
Edible mushrooms, including shiitake, contain polysaccharides and other compounds with potential cholesterol-lowering and immune-modulating effects.
View SourceEdible mushrooms and beta-glucans: impact on human health
Review
A review of mushroom-derived beta-glucans notes immune-modulating and potential cardiometabolic effects, while emphasizing that human data on lipid and glycemic outcomes are still emerging.
View SourceDietary mushrooms and cardiometabolic risk
Review
Observational and experimental evidence suggests regular mushroom intake may support healthier body weight and cardiovascular risk markers when part of a balanced diet rich in vegetables.
View SourceShiitake mushrooms: nutrition, benefits, and culinary uses
Overview
Consumer-oriented summary highlighting that shiitake mushrooms provide beta-glucans, eritadenine, minerals, and vitamin D, with potential benefits for cholesterol, blood pressure, and immune health, though more research is needed for definitive diabetes outcomes.
View SourceMaster Your Metabolic Health
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Frequently Asked Questions About Shiitake Mushroom and Blood Sugar
Medical Disclaimer
The information provided on this page is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician, dietitian, or other qualified health provider with any questions you may have regarding a medical condition or dietary changes, especially if you have diabetes, allergies, or other health concerns. Never disregard professional medical advice or delay in seeking it because of something you have read here.
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