Cornstarch: Is It Healthier Than Flour, Safe, and Are There Side Effects?

Cornstarch is a product made from parts of the corn kernel. Cornstarch is a pure carbohydrate, but flour has more nutrients.

Cornstarch is a common ingredient in a wide variety of foods and beverages. It’s used by home cooks and in commercial settings. 

Cornstarch is not a very nutrient-rich food, though, so it’s an open question whether or not cornstarch is bad for you. In general, if you’re looking for a good flour alternative, cornstarch is not your healthiest choice. 

Cornstarch is a product made from parts of the corn kernel. It’s made by milling the starchy center of the kernel into a finely grained product. 

Cornstarch is considered a refined grain. The refining process removes parts of the corn kernel, which also removes certain nutrients from the final product. 

This product is mostly used as a thickener in cooking. You can add it to sauces, soups, and baked goods to modify the texture without significantly changing the flavor. It also has uses as a commercial thickening agent. It’s used in products as diverse as:

• Paint
• Glue
• Commercial cleaners

There are a few different varieties of cornstarch. These include: 

• Normal cornstarch
• Waxy cornstarch 
• High-amylose cornstarch 

Of the three, normal cornstarch and waxy cornstarch are easier to digest than high-amylose cornstarch. 

Cornstarch is essentially a pure carbohydrate. Starch is the main carbohydrate found in cornstarch. 

There are three types of starch found within cornstarch: 

• Rapidly digested. This version breaks down quickly in your digestive system. It can cause quick spikes in your blood sugar levels after meals. 
• Slowly digested. Your body needs more time to break down this type of starch. This type gradually releases sugar into your blood. 
• Resistant starch. This type of starch can’t be digested the way that your body normally digests food — with enzymes in your small intestine. However, it can be broken up and fermented by microorganisms that live in your intestines. This creates short-chain fatty acids that are useful for both your health and the health of the organisms living in your gut (your microbiome). 

The nutrients found in 100 grams of cornstarch include: 

• Water — 8.32 grams
• Protein — 0.26 grams
• Total fat — 0.05 grams
• Total carbohydrates — 91.3 grams
• Fiber — 0.9 grams
• Calcium — 2 milligrams
• Iron — 0.47 milligrams
• Magnesium — 3 milligrams
• Phosphorus — 13 milligrams
• Potassium — 3 milligrams
• Sodium — 9 milligrams
• Zinc — 0.06 milligrams
• Copper — 0.05 milligrams
• Manganese — 0.053 milligrams
• Selenium — 2.8 micrograms
• Choline — 0.4 micrograms

Cornstarch can sometimes be used as a flour substitute. They both help thicken certain foods and beverages. Still, you can’t just swap all of the flour in your recipes for cornstarch. That would significantly alter the texture and consistency of your baked goods. 

Some recipes require certain ratios of starch to gluten. Normal wheat flour contains both ingredients. Cornstarch, though, is gluten-free. 

Compared to cornstarch, 100 grams of enriched, bleached, wheat flour contains significantly more: 

• Protein — 10.9 grams
• Calcium — 19 milligrams 
• Iron — 5.62 milligrams
• Magnesium — 26.7 milligrams
• Selenium — 15.7 micrograms

There are many flour alternatives on the market that are healthier than cornstarch. If you’re looking for a good flour substitute, try something like: 

• Almond flour. This contains healthy fats and fibers. It’s also gluten-free. It can make you feel fuller than normal flour and can reduce your blood sugar after snacking. 
• Coconut flour. This gluten-free flour has beneficial fats and fibers. It’s great for grain-free diets.  
• Oat flour. This flour has more fiber and protein than normal wheat flour. Gluten-free versions also exist. 

If you do want to use cornstarch as a flour replacement, you should only use one and a half teaspoons of cornstarch for every tablespoon of wheat flour that a recipe requires.

Cornstarch has a high glycemic index. This is a scale that assesses the carbohydrates in a particular food by seeing how quickly they affect your blood sugar levels. Foods with a high glycemic index cause your blood sugar levels to rapidly go up after you’ve eaten. 

This can be a problem for people who need to constantly regulate their blood sugar, like those with type 2 diabetes. These foods can also lead to problems like obesity. 

If you have a medical issue that can be affected by rapid spikes in your blood sugar, you should try to avoid foods with a lot of cornstarch. Alternatively, try using high-amylose cornstarch because it has a higher amount of resistant starch than other varieties. This type won’t affect your blood sugar levels as much as regular cornstarch.  

Eating cornstarch can also be problematic for your overall heart health. Data indicates that low-carbohydrate diets can greatly benefit people who are concerned about their hearts. Specifically, they lower your risk of heart disease and may also positively impact your long-term heart health. Carbohydrate-rich cornstarch is difficult to incorporate into a low carbohydrate diet.

Plus, research shows that carbohydrates with a high glycemic index are the worst for your heart’s health. Eating lots of carbohydrates like cornstarch can, therefore, greatly increase your risk of developing heart disease.    

There are a few reasons why cornstarch could be a healthy choice for a thickening agent. The fact that cornstarch is gluten-free is great for people with conditions like Celiac disease and non-Celiac gluten sensitivity (NCGS).

Celiac disease is a genetically-caused autoimmune disorder. It affects around one in every 100 people. Symptoms of those exposed to gluten can vary widely and include problems like diarrhea, malnutrition, and infertility. People with NCGS also need to avoid gluten in their diets, or they will experience symptoms like headaches and fatigue. 

Normal wheat flour contains lots of gluten. So do barley and rye products. Pure cornstarch doesn’t contain any gluten, though, so it’s safe for people with both of these conditions. 

Cornstarch also contains a small amount of dietary fiber. Americans typically don’t get enough dietary fiber, so even the little bit in cornstarch can help. 

If you don’t get enough fiber, that can increase your risk of encountering conditions like: >

• Heart disease 
• Colon cancer
• Insulin sensitivities

Finally, cornstarch is sometimes used to help people with glycogen storage diseases like severe fasting hypoglycemia. These people need a constant input of sugar because their bodies can’t store it properly. Taking doses of cornstarch can help them go longer without eating. This can also help them sleep through the night.