Introduction: What Is Resistant Starch?
Resistant starch is a type of dietary fiber that resists digestion in the small intestine and ferments in the large intestine. Unlike regular starch, which is broken down into glucose and absorbed in the small intestine, resistant starch behaves more like soluble fiber. It offers a variety of health benefits, including improved gut health, better blood sugar control, and increased feelings of fullness.
But do potatoes have resistant starch? This is a common question among health enthusiasts and those following low-carb, ketogenic, or diabetic-friendly diets. Potatoes are often considered a starchy vegetable and are sometimes avoided due to their high glycemic index. However, the way potatoes are prepared and consumed can significantly influence their starch composition — including the presence of resistant starch.
In this article, we’ll explore what resistant starch is, how it benefits the body, and whether potatoes are a significant source of this beneficial compound. We’ll also discuss how to maximize resistant starch content in potatoes and compare them to other food sources.
Understanding the Different Types of Resistant Starch
Before diving into whether potatoes have resistant starch, it’s important to understand the different types of resistant starch. There are four primary types:
- Type 1: Physically inaccessible starch, found in whole or partially milled grains, seeds, and legumes. It’s trapped within the cell walls and cannot be digested.
- Type 2: Intrinsic granular starch, which is naturally resistant due to its physical structure. It’s found in raw potatoes, raw bananas, and some legumes.
- Type 3: Retrograded starch, formed when starchy foods are cooked and then cooled. This category is especially relevant to potatoes.
- Type 4: Chemically modified starch, often used in food processing to impart specific textures without full digestion.
The resistant starch content in potatoes is primarily Type 2 and can convert to Type 3 through common cooking and cooling techniques.
Do Potatoes Have Resistant Starch? The Science Behind It
Yes, potatoes do contain resistant starch, but the amount depends heavily on both the potato variety and how it’s prepared. According to several studies, raw potatoes have a high resistant starch content — about 7–8 grams per 100 grams of raw potato. However, once potatoes are cooked, their starch becomes gelatinized, meaning it’s easier to digest and the resistant starch content dramatically decreases.
One of the fascinating properties of resistant starch is that it can return to a more resistant form when cooked potatoes are cooled. This process is called retrogradation. Whether you’re eating potato salad or baked potatoes the next day, cooling potatoes after cooking can increase their resistant starch levels significantly.
For example:
- A hot, freshly cooked potato has almost no resistant starch — around 0.3 grams per 100 grams.
- If that same potato is cooled in the fridge for 24 hours, it can gain around 3–4 grams of resistant starch per 100 grams.
This means that by making simple changes to how we prepare and eat potatoes, we can increase their content of resistant starch — and along with it, the health benefits.
How Potato Type Influences Resistant Starch Levels
Not all potatoes are created equal. Some varieties naturally contain higher levels of resistant starch than others:
- Yukon Gold Potatoes: These are higher in both digestible and resistant starch compared to other types.
- Russet Potatoes: Typically richer in starch overall, but much of it becomes digestible after cooking.
- Sweet Potatoes: While nutritious, they generally contain less resistant starch than white or yellow potatoes, especially when cooked.
Additionally, smaller whole potatoes (like fingerlings) can retain more resistant starch when boiled and cooled than larger varieties that are mashed or baked.
How Cooking Methods Affect Resistant Starch Content
As previously discussed, cooking breaks down starch granules, a process called gelatinization, reducing resistant starch levels. However, certain techniques — especially those that involve cooling — allow the structure of starch molecules to realign into a more resistant form.
Here’s how different cooking methods influence resistant starch levels:
| Cooking Method | Average Resistant Starch (per 100g, cooked) |
|---|---|
| Boiled and cooled | 3–4 g |
| Baked and cooled | 2–3 g |
| Mashed | 1–1.5 g |
| Fried (French fries) | Negligible |
| Raw | 7–8 g |
From this table, it’s clear that boiling and cooling potatoes is the most effective method to preserve, and even enhance, the amount of resistant starch in this beloved tuber.
Why Resistant Starch in Potatoes Matters
The health benefits of resistant starch in potatoes are gaining scientific attention. These benefits parallel those seen from fiber-rich plant foods and are especially valuable for metabolic and gut health.
1. Improved Blood Sugar Control
Resistant starch has a milder impact on blood sugar than regular starch. Since it’s not broken down in the small intestine, it doesn’t cause sharp glucose spikes. This can help in managing insulin sensitivity and is especially beneficial for people with type 2 diabetes.
A meal containing cooled, cooked potatoes instead of hot ones can significantly lower the post-meal glucose response, offering a practical way to enjoy this vegetable without the usual glycemic setbacks.
2. Gut Health and Digestive Benefits
Resistant starch acts as a prebiotic — it feeds the beneficial gut bacteria in the large intestine. These bacteria ferment resistant starch into short-chain fatty acids (SCFAs) such as butyrate, which nourish the colon cells and reduce inflammation.
Butyrate is also linked to protection against colon cancer and improved gut barrier function. Including potatoes with resistant starch may therefore support digestive wellness.
3. Increased Satiety
Resistant starch can also increase feelings of fullness and prolong satiety after meals. Because the body does not fully digest this type of starch, energy absorption is gentler and more prolonged. Pairing potatoes with proteins or healthy fats can further extend this effect.
How to Maximize Resistant Starch in Potatoes
If you’re interested in harnessing the power of resistant starch in potatoes, here are some science-backed strategies:
1. Cook Then Cool
Allowing potatoes to cool in the refrigerator after cooking (for at least 24 hours) creates retrograded starch. This structural change allows the starch to “reset” into a more crystalline form that is harder for digestive enzymes to break down.
2. Reheat Cold Potatoes
Many fear eating cold potatoes, but interestingly, you can reheat them without significantly reducing their resistant starch content. A 2012 study showed that reheating cooled potatoes in the oven or microwave can preserve most of the resistant starch. This opens the door to enjoying potato dishes without losing significant nutritional benefits.
3. Avoid High-Fat Additions
While butter, sour cream, and cheese make potatoes tasty, they can slow gastric emptying and increase calorie density without enhancing resistant starch. If your goal is digestive or blood sugar support, enjoy potatoes with vinegar-based dressings or fresh herbs.
4. Pair With Acidic Ingredients
Adding vinegar or lemon juice can help slow starch digestion. Acid lowers the pH of the food and delays carbohydrate breakdown, offering a synergistic effect with resistant starch.
Comparing Resistant Starch Content: Potatoes vs. Other Foods
While potatoes are a decent source of resistant starch, especially when cooled after cooking, they aren’t the only — or even the top — food for this nutrient.
Here’s a comparison of resistant starch per 100g:
| Food Type | Average Resistant Starch (g/100g) |
|---|---|
| Raw potato | 7–8 |
| Cooked and cooled rice | 1.5–2 |
| Cooked and cooled pasta | 2–3 |
| Raw plantains | 8–10 |
| Canned chickpeas (drained) | 2.5–3 |
| Green bananas (raw) | 8–12 |
While potatoes don’t outperform green bananas or plantains in resistant starch content, they remain a versatile and widely consumed option — especially for those who prefer savory over fruity flavors.
Are Potatoes Good for Weight Loss?
Potatoes are often thought of as too high in carbs to be considered “diet-friendly.” But the resistant starch and fiber content — especially when potatoes are cooled — can support weight management.
A few factors make potatoes a potentially helpful inclusion:
- High in resistant starch, promoting satiety
- Naturally low in calories — a medium baked potato is only around 110 calories
- High satiety index compared to many processed carbohydrates
However, portion control and preparation methods are key. Pairing potatoes with vegetables, lean proteins, and limiting fatty toppings or frying can make them an excellent, satisfying component of a balanced diet.
Conclusion: Embracing the Resistant Starch in Potatoes
So, do potatoes have resistant starch? The answer is a resounding yes — but only under certain conditions. Raw potatoes contain naturally occurring resistant starch, and cooked and cooled potatoes undergo retrogradation to regain some of that beneficial structure. By simply adjusting our cooking methods — boiling, cooling, and even reheating — we can enjoy potatoes while tapping into their gut and blood sugar benefits.
Potatoes should not be altogether rejected from healthy diets. Instead, we can make informed choices to enhance their value. Whether you’re a fitness enthusiast, someone managing diabetes, or simply looking to improve your digestive wellness, cooled potatoes can be a smart, accessible, and affordable solution.
Incorporate them in salads, eat leftovers cold, and aim for whole, unprocessed forms of the potato. With a little kitchen science and mindful eating, you can reap the benefits of resistant starch from this humble root vegetable — all without sacrificing flavor.
References:
- USDA Food Composition Database
- Turner NW, Morell C, Copeland L. (2015). Interactions between starch and phenolic compound affect the digestibility of the starch and uptake of phenolics in a model system. Food Chemistry.
- Nilsson AC, Ostman EM, Holst JJ, Björck IM. (2008). Including indigestible carbohydrates in the evening meal of healthy subjects improves glucose tolerance, lowers inflammation, and potentiates sleep.
What is resistant starch and why is it important?
Resistant starch is a type of starch that resists digestion in the small intestine and ferments in the large intestine. This fermentation process produces beneficial short-chain fatty acids like butyrate, which can support gut health. Due to its fiber-like properties, resistant starch is often grouped with dietary fibers and is associated with a range of health benefits, including improved digestion, better blood sugar control, and enhanced satiety.
Unlike regular starch, resistant starch doesn’t cause spikes in blood sugar levels, making it a key component in managing insulin sensitivity and supporting metabolic health. It also promotes the growth of beneficial gut bacteria, contributing to a balanced microbiome. Because of these beneficial effects, resistant starch is of particular interest to nutritionists and health-conscious individuals alike.
Do potatoes contain resistant starch?
Yes, potatoes do contain resistant starch, though the amount varies depending on the type of potato and how it’s prepared. Raw potatoes have the highest amounts of resistant starch, but very few people eat them raw due to texture and potential digestive discomfort. Most studies suggest that the cooling of cooked potatoes significantly increases their resistant starch content, especially after refrigeration for several hours or overnight.
Interestingly, the process of cooking and then cooling potatoes—known as retrogradation—causes the starch structure to change, making more of it resistant to digestion. For instance, potato salad made with cooled boiled potatoes contains more resistant starch than hot mashed potatoes. Choosing whole potatoes and allowing them to cool after cooking can maximize their resistant starch content and improve their nutritional profile.
Which potato varieties have the most resistant starch?
While most potato varieties contain resistant starch, some are naturally richer in starch than others and thus have more potential to form resistant starch after cooking and cooling. Waxy potatoes tend to have less starch and may yield less resistant starch, while starchy varieties like Russet or Idaho potatoes typically have higher overall starch content, which translates to more resistant starch when cooled properly.
However, the variety alone isn’t the only factor. The way potatoes are prepared and stored also significantly impacts final resistant starch levels. Regardless of the type, cooling potatoes in the refrigerator after cooking increases their resistant starch content. Reheating them after cooling doesn’t diminish these benefits entirely, though eating them cold preserves more resistant starch than reheating.
How does cooking affect the resistant starch content in potatoes?
Cooking breaks down the cellular structure of potatoes and gelatinizes the starch, reducing the amount of resistant starch temporarily. When potatoes are cooked, their starch granules absorb water and swell, making them easier to digest. This increases the digestible starch content but decreases the resistant portion. However, this change is reversible to some extent through proper post-cooking handling.
Cooling potatoes after cooking allows the starch to undergo retrogradation, during which the molecular structure realigns into a form that’s more resistant to digestion. For best results, cook potatoes and then refrigerate them for at least 24 hours before consumption. Even reheating after cooling doesn’t remove all the resistant starch, though it might slightly reduce the overall content compared to eating them cold.
What are the health benefits of the resistant starch in potatoes?
Consuming resistant starch from potatoes has been associated with several health benefits. It helps regulate blood sugar levels by slowing down the absorption of glucose, which can be especially helpful for people with insulin resistance or type 2 diabetes. Additionally, resistant starch supports a healthy gut by acting as a prebiotic, meaning it feeds beneficial gut bacteria, which in turn can improve digestion and support immune function.
Regular intake may also help with weight management, as it increases feelings of fullness and reduces appetite. This is due to its slower digestion and positive impact on satiety hormones. Moreover, the fermentation of resistant starch in the colon produces short-chain fatty acids like butyrate, which nourish the cells lining the intestines and may reduce inflammation and lower the risk of certain colonic diseases, such as colorectal cancer.
Can I increase the resistant starch in potatoes by storing them differently?
Yes, storing potatoes properly after cooking can significantly increase or preserve the amount of resistant starch. The best method involves cooking the potatoes and then cooling them in the refrigerator for several hours or overnight. This cooling process facilitates retrogradation, where starch molecules restructure into a form that resists digestion. The longer the cooling period, the more resistant starch is formed.
Reheating stored potatoes doesn’t entirely reverse this process, so dishes like cold potato salad or leftover mashed potatoes that have been chilled overnight are still better sources of resistant starch than freshly cooked, hot potatoes. Freezing can also preserve resistant starch effectively, especially if you’re planning to use the potatoes in a future meal. The key is to avoid consuming them immediately after cooking when the resistant starch levels are at their lowest.
How much resistant starch is in potatoes compared to other foods?
Potatoes are a moderate source of resistant starch compared to other foods. For example, one medium cooked and cooled potato can provide around 3 to 4 grams of resistant starch. By contrast, green bananas, raw oats, or certain types of legumes like lentils or kidney beans can offer higher concentrations, especially when consumed raw or prepared in a way that enhances resistant starch content.
While potatoes may not be the richest source, they are more commonly consumed in many diets and offer a versatile, palatable way to increase resistant starch intake. Their starch content, especially after cooling, makes them a valuable component of a balanced diet for individuals aiming to improve gut health, enhance satiety, or regulate blood sugar levels through dietary means.