If you didn’t know anything at all about how to tell a good dog food from a bad one, you would probably take the health claims made by manufacturers on pet food packages at face value. For example, a manufacturer might claim that their product is “all natural,” but what exactly does that mean? Pet foods are not as closely regulated as human foods, so descriptors like this don’t have a standard definition. Another thing you may not realize about pet foods is that many of the ingredients you think about as healthy for your own consumption are actually unhealthy for your dog – one of them is corn.
How is Corn Used in Dog Food?
There is a great deal of debate regarding the quality of corn as an ingredient in dog food. Many veterinarians claim that corn provides a valuable source of digestible carbohydrate and dietary fiber for dogs. In fact, many veterinarians sell dog food products in their clinics that are made with high quantities of grain, including corn-based ingredients. As a grain, corn can be used in a variety of different ways. Below you will find a list of definitions for different corn-based ingredients as defined by The Dog Food Project and the American Association of Feed Control Officials (AAFCO):
- Corn Bran – The outer coating of the corn kernel; an inexpensive source of fiber that serves primarily as a filler ingredient to add bulk to lower quality pet foods.
- Corn Cellulose – A product obtained by use of a chemical process from the outer cell walls of corn; typically used to add bulk and fiber to inexpensive pet foods, has no nutritional value.
- Corn Germ Meal – Ground corn germ that consists of the germ and other parts of the corn kernel from which the corn oil has been removed; an inexpensive by-product rich in protein but often used as a filler.
- Corn Gluten – An inexpensive by-product of human food processing that serves mainly as a binder and offers very little nutritional value.
- Corn Gluten Meal – The dried residue from corn after the larger part of the germ and starch has been removed, the separation of which is made by a process used in the wet milling manufacture of corn starch or syrup; an inexpensive by-product that serves mainly as a binder and a source of protein.
- Corn Syrup – A syrup made from prepared cornstarch, typically used as a sweetener; typically used as an additive in pet foods to make the product more attractive.
In addition to these corn derivatives, you may also see things like “whole grain corn” or “ground corn” on the ingredients list – you may also see “corn flour” which is simply ground corn. Although you may think of corn as a healthy whole grain for inclusion in your own diet (and there are many veterinarians who would agree that it is a beneficial ingredient for dogs as well), even AAFCO states that whole grains are generally not good for most dogs. Of whole grains in general AAFCO states, “whole grains are commonly used as a carbohydrate source for energy… however, in lower quality pet foods, they may be used as the main ingredient, which is not healthy for most dogs”. Even if you agree with veterinarians that corn is not necessarily a harmful ingredient, you should be able to understand that as a grain and a plant-product, it has no place at the top of the ingredients list for any quality dog food product.
What are the Nutritional Benefits of Corn?
Before you can make up your own mind regarding corn as a beneficial or harmful ingredient, you should learn about its nutritional content. According to Organic Facts, corn is a rich source of Vitamins A, B, and E as well as minerals like phosphorus, magnesium, iron, copper, and zinc. As a source of energy, corn contains about 342 calories per 100 grams which is the highest calorie content by weight for cereal grains. One cup of corn contains about 12 grams of dietary fiber and, in humans, it has been linked to relief from digestive issues such as constipation and has even been shown to help reduce the risk for colon cancer.
Nutritional Myths About Corn in Pet Food
Given the previously stated nutritional benefits, you might be thinking that corn doesn’t sound so bad. Before you make your final decision, however, you should view the issue from both perspectives. Here are some myths and misconceptions (along with the facts behind them) that the pet food industry has been perpetrating about corn for years:
- Corn is highly digestible for dogs. In general, whole grains are considered more easily digestible than grain-based by-products for dogs, but that doesn’t mean that all grains are good for them. The fact of the matter is that corn needs to be processed in order to make it digestible for dogs. This process involves refining the whole kernel into flour and then cooking it. Even if the corn on a pet food label is listed as “whole”, it is still likely to have gone through this process.
- Corn is a low-glycemic ingredient. Not only do many dog owners worry about the digestibility of the carbohydrates in their dog’s food, but they also worry about the glycemic index (GI) – the degree to which the product affects your dog’s blood sugar. Some say that corn is a low-glycemic food, but it actually varies depending how it is processed – the more finely it is ground, the higher the GI rating. To give you an idea what this means, consider the fact that meats generally have a GI rating of 0. Barley is rated at 25 and oatmeal at 49. Whole corn has a GI rating of 53 and corn meal has a rating of 69.
- Corn is a nutritious ingredient for dogs. Many people associate the words “whole grain” with healthy, but that is not necessarily the case for corn – especially when it comes to dogs eating corn. One of the best ways to measure the nutritional value of an ingredient is to check its “completeness score” as determined by the USDA’s National Nutrient Database. This score is based on a measure of how complete an ingredient is in terms of its vitamin, mineral, and fiber content – the higher the score, the more “complete” the ingredient. Corn is valued at 34 while quinoa earns a 45, peas a 53, and spinach a whopping 91.
- Corn is biologically valuable for dogs. When considering whether an ingredient is good for your dog or not, you have to consider more than just the nutrient content – you also have to think about the biological value. The term “biological value” applies primarily to proteins and it is a scale for measuring their nutritional worth – basically, it is a measurement of the protein’s ability to provide essential amino acids. Eggs have the highest biological value at 100 with fish meal at 92 and beef at 78 – corn gets a 54.
By now it should be clear to you that things aren’t always what they seem – especially in the pet food industry. There are many little tricks that pet food manufacturers use to make their products appear better than they really are. One of these tricks is called ingredient splitting and it is frequently used for corn ingredients. As you may already know, the ingredients list for a pet food product is listed in descending order by volume – that means that the ingredients used in the highest volume appear at the top of the list. The top of the list is where you want to see the quality ingredients – things like meat.
Now, put yourself in the shoes of a pet food manufacturer who wants to make as much money on his product as possible. What would you do? For one thing, you might use more low-quality ingredients than high-quality ingredients because they are cheaper. But your customers don’t want to see “corn” at the top of the ingredients list. The way many pet food manufacturers get around this problem is by subdividing an abundant ingredient in to smaller portions. Instead of just using “corn”, you might divide it into “corn meal” and “corn flour”. In doing so, you split the volume of the corn in half, allowing a higher quality ingredient to appear before these ingredients on the list.
Is Corn Okay for My Dog?
In the end, it is really up to you to decide whether or not corn is an okay ingredient for your dog. This will depend on variety of factors. For one thing, you need to think about whether corn is the main ingredient in the product or if it is only used in a small quantity. You also need to think about whether your dog is going to have a reaction to the corn. The fact of the matter is that grains like corn cause allergies or insensitivities in many dogs, but part of that has to do with the quality of the grain and whether or not it has been contaminated by something undetectable.
The pet community may never come to an agreement regarding whether corn is okay for dogs, but you need to make this decision for yourself. Take what you have learned about corn as an ingredient in dog food (both the good and the bad) and decide if you want to take the risk with your dog. Our personal recommendation is to avoid corn as an ingredient in dog food, but everyone is entitled to their own opinion.