Cornstarch is a versatile ingredient you probably have in your pantry. It can thicken foods such as soups and pie filling. It also helps form a crisp crust when used as coating for fried foods. Although it enhances the flavor of many foods, the health benefits of eating cornstarch are limited.
Cornstarch is gluten-free so it can serve as a wheat flour substitute and can be a quick source of glucose and calories for athletes, but the health benefits of cornstarch are limited.
What Is Cornstarch?
Starch is the most abundant carbohydrate in the human diet, accounting for more than 50 percent of your carbohydrate consumption. Starch also accounts for 70 to 80 percent of all calories eaten by humans worldwide. It is found in plant walls and is particularly plentiful in tubers such as cassava and potatoes and in grains such as wheat, oats, barley, rice and corn.
Each corn kernel has three main parts: the germ, bran and endosperm. The bran is the hard outside shell, which is high in fiber. The germ is the lower part of the kernel, which can sprout into a new plant and is rich in fats. Most of the starch in corn is inside the endosperm, which makes up the interior layer of the kernel.
To make cornstarch, sometimes called maize starch, farmers first separate the bran, germ and endosperm of corn kernels. Next, the starch from the endosperm of the kernels is extracted through a process called wet milling. Finally, the cornstarch is dried and packaged. Cornstarch is considered a highly processed food.
Besides being used as a common food additive, cornstarch has many commercial uses. It can be found in batteries, baby powder, bioplastics, matches and cosmetics. When mixed with water, cornstarch forms a non-Newtonian fluid called "oobleck," which is a liquid when stirred but a solid when force is exerted upon it.
Health Benefits of Cornstarch
Most of the nutrition in corn is found in the bran and germ of the kernels. Because cornstarch does not contain the germ and bran of the corn kernel, as cornmeal and corn flour often do, it is nearly flavorless. It also lacks nutrition.
One cup of commercial cornstarch has 488 calories, with little or no fiber, protein, fat or vitamins. Because of this lack of nutrition, the health benefits of cornstarch are limited. If you are an underweight individual or a weight trainer looking to gain weight quickly, cornstarch can help increase your calorie intake.
Your digestive system breaks down carbohydrates into glucose, which your body uses as fuel. Without the fiber, fat or protein to slow down this process, cornstarch provides your body with energy more quickly than whole-grain carbs.
Another benefit of cornstarch is that it is gluten-free. Because of this, it can serve as a wheat flour substitute for those with celiac disease or another form of gluten intolerance. That said, oat flour is also gluten free, but is a more nutritious option. One cup of oat flour has significantly more fiber, protein, potassium, phosphorous and magnesium than cornstarch.
Health Risks of Eating Cornstarch
Without any fiber, protein or fat to slow down the conversion of carbohydrates into blood glucose, eating high amounts of cornstarch can cause a spike in blood glucose levels. A December 2015 study published in the American Journal of Clinical Nutrition found that consumption of starches increases risk of Type 2 diabetes, while eating fiber decreases risk.
Just as with other grains, when it comes to corn, eating the whole unprocessed kernel, with the bran and germ still intact, is healthier than eating its processed derivative — cornstarch. When eating whole corn, you still consume the starch inside the kernels — which your body needs for fuel — but you also get fiber, protein, vitamins and minerals to help slow down the absorption of glucose and decrease risk of vitamin deficiencies.
One medium ear of corn has about:
- 88 calories
- 1.4 grams of fat
- 19.1 grams of carbs
- 3.3 grams of protein
- 2 grams of fiber
- 6.4 grams of sugar
- 275 milligrams of potassium
- 91 milligrams of phosphorous
Benefits of Modified Cornstarch
There are three different ways to consume the starch in corn: as commercial cornstarch used for cooking and devoid of most nutrition; as cornstarch still intact inside the kernel and surrounded by the bran and germ of the corn; and as modified cornstarch. Modified cornstarch is altered chemically, physically or enzymatically to improve a certain property, such as digestibility.
One type of modified cornstarch — high-amylose cornstarch — has been shown to have positive effects on health. A December 2014 report from Rutgers University states that high-amylose cornstarch decreases blood glucose and insulin response and increases satiety, or how long someone feels full after eating.
Cornstarch is composed of two polymers: amylose and amylopectin. In naturally produced cornstarch, amylopectin, which has a smaller molecular profile, is more abundant than amylose. In high-amylose cornstarch, this ratio is modified, and the concentration of amylose is increased to 40 to 70 percent.
Because amylose has a larger molecular profile than amylopectin, high-amylose cornstarch is more difficult to digest, which, as the Rutgers University report explains, makes it a healthier option than unmodified commercial cornstarch. Talk to your health care provider if you are predisposed for Type 2 diabetes and are looking for food options to keep your blood glucose and insulin levels in check. High-amylose corn starch might be a good option.
Topical Applications of Cornstarch
Using cornstarch for the skin is a good topical option if you have certain medical conditions. The National Institute of Diabetes and Digestive and Kidney Diseases suggests applying talcum powder or cornstarch to feet after washing to prevent diabetes related foot infections. Cornstarch helps keep naturally moist areas of the body dry.
The National Cancer Institute also suggests applying cornstarch to skin as a way to relieve pruritus. Pruritus is an itchy feeling that makes you want to scratch your skin, which is caused by several medical conditions, including liver, kidney and thyroid disorders, blood disorders and cancer. These cornstarch medical uses are another reason to have this ingredient in your home.
- Chemistry: LibreTexts: "5.1: Starch and Cellulose"
- USDA: "Basic Report: 20027, Cornstarch"
- Encyclopedia of Food Grains: "Maize: Wet Milling"
- Encyclopaedia Britannica: "Endosperm"
- Harvard T.H. Chan School of Public Health: "Whole Grains"
- Corn Refiners Association: "Starches"
- Cornell Chronicle: "The Secret of Oobleck Revealed at Last"
- USDA: "Basic Report: 20132, Oat Flour, Partially Debranned"
- American Journal of Clinical Nutrition: "Carbohydrate Quality and Quantity and Risk of Type 2 Diabetes in US Women"
- USDA: "Basic Report: 11167, Corn, Sweet, Yellow, Raw"
- Food and Drug Administration: "Science Review of Isolated and Synthetic Non-Digestible Carbohydrates"
- Foods: "Starch Characteristics Linked to Gluten-Free Products"
- Corn (Third Edition), 2019: "Specialty Corns"
- National Institute of Diabetes and Digestive and Kidney Diseases: "Diabetes and Foot Problems"
- National Cancer Institute: "Pruritus (PDQ®)–Patient Version"
- Rutgers University: "Battling Obesity With Resistant Starch"