Cornstarch is popular in baking recipes as a filler and thickening agent, and it’s also an ingredient in many processed foods, but is it bad for you?
In this article we’ll review some of the medical research on cornstarch to determine whether it’s a risk to your health, as well as offer some healthier alternatives.
High Glycemic Index
Foods rich in carbohydrates can be measured on a scale called the glycemic index, which indicates how quickly the food raises blood sugar when eaten in isolation.
Blood sugar spikes can be harmful to the cardiovascular system even in nondiabetic subjects, as suggested by an animal study.
The glycemic index is a scale from 1-100, and cornstarch is a 97 which is very high. This suggests that cornstarch can spike blood sugar to unhealthy levels if eaten in large portions.
It’s worth noting that the glycemic index changes based on the composition of the meal. Eating carbs with fats, with acids and with proteins all lower the glycemic index of the meal overall. That being said, higher glycemic index foods are still considered somewhat less healthy.
Low in Nutrients
Cornstarch is a nutrient-poor food. Per calorie, it doesn’t offer much nutritional value. In large quantities it can provide a fraction of certain trace minerals like selenium, but in the amount used in processed foods and most recipes, cornstarch isn’t providing much other than filler carbs.
It’s important that health-conscious consumers try to eat nutrient-dense foods for most of their calories, as this dietary model has been shown in medical research to improve health outcomes overall, which shouldn’t be surprising.
It’s a common misconception that corn starch is made by grinding whole corn kernels into a flour. However, that is corn flour, while corn starch is made by removing the outer layer of a corn kernel and processing the endosperm of the corn kernel into a consistent, fine white powder.
Much of the nutritional value of corn is lost during this manufacturing process.
Eating a minimally processed, whole-foods diet is generally associated with improved health, and cornstarch clearly doesn’t fit into that diet model.
Healthier Cornstarch Alternatives
Psyllium husk is a fibrous powder made from a plant called Plantago ovata. It’s dense and can act as a thickening agent like cornstarch.
The reason we consider it healthier than cornstarch is because it’s much higher in fiber, and lower glycemic index. 100 grams (g) of psyllium husk powder contains 75 g fiber according to the U.S. Department of Agriculture (USDA).
100 g of cornstarch contains only 1.9 g fiber.
We know from medical research that increased fiber intake benefits gastrointestinal (GI) health, and can aid in weight loss efforts, which is why psyllium husk is one of the most popular fiber products in GI supplements like Colon Broom.
Coconut flour is made by drying whole coconuts, making it a minimally-processed alternative to cornstarch.
We consider it to be a healthier alternative because it’s much higher in nutrients. Per 100 g, coconut flour contains 1,867 milligrams (mg) potassium, 67 mg calcium and 33.3 g fiber according to the same USDA FoodData database linked above.
Cornstarch contains 3 mg potassium, 2 mg calcium and 0.9 g fiber for the same dose.
The database didn’t measure trace minerals like selenium and phosphorus, but it’s likely coconut flour would be higher in these too.
Clearly, coconut flour provides a much higher dose of vitamins and minerals than cornstarch. It can also make a great replacement because it’s relatively odorless and plain.