Updated: Feb 16, 2019
Grain-free diets are everywhere you look these days! But are they really any better for your pet than regular commercial diets? The most common reasons most of my clients elect for a grain-free diet is that they have come to believe that these diets are higher quality, that grain is not an appropriate energy source, and/or they suspect their pet has a food allergy. Today we will break down all of these myths.
Just because it's Grain-free doesn't mean it's the healthier option
Regarding the perceived increased quality of grain-free diets, there is no available research to back up this claim. Grains are, in fact, a nutritious source of complex carbohydrates, protein, fats, vitamins and minerals. Additionally, many grain-free diets are often substituted with other inexpensive starches such as potatoes, legumes, and tapioca. The single most important way to ensure your pet is getting a high quality diet is to purchase diets from a reputable pet food company that performs the Association of American Feed Control Officials (AAFCO) feeding trials. You can read more about AAFCO here.
Research does not support the use of grain-free diets
Are domesticated animals really meant to be utilizing grain as an energy source? A study performed in a 2013 issue of the journal Nature suggests the answer is yes! This study found that domesticated dogs have adapted genes specializing in starch (and thus grain) digestion over time. But what about cats? Since they are carnivores, shouldn't they be grain-free? A 2017 study by nutritionists at Tufts University found that many grain-free cat diets contained similar amounts, and sometimes higher amounts, of carbohydrates compared to regular diets. Cats can use carbohydrates as an energy source, but they do utilize proteins more efficiently than carbohydrates, and do require a higher level of protein in their diet than dogs. Grain-free diets are clearly not the solution to this, so speak with your veterinarian to determine the best type of food for your feline companions.
Proteins are the typical allergy, not grains
Finally, we come to food allergies, the biggest myth of all. Where this falsehood originated is a mystery, but the reality is that proteins are typically the number one food allergy in dogs and cats as shown by a 2016 study. The most common allergens in dogs are beef, chicken, and dairy. In cats, they are beef, fish, and chicken. It should be noted that approximately 20% of dogs and about 5% of cats in this study did have grain allergies. While grain allergy is possible, it is not probable for most pets. Additionally, any over the counter diet is inappropriate for treating a suspected food allergy regardless. Diet manufacturers can substitute any ingredient that they want as long as the nutrient analysis remains the same. If you picked a certain over the counter food because it contained fish as a protein source, you could very well be feeding chicken or any number of unknown ingredients to your pet. Secondly, cross-contamination between different diets is a known phenomenon in the manufacturing process. Even if the manufacturer, is in fact, sticking to the posted ingredient list for a certain diet, the food is still rendered useless for a food trial since it may contain remnants of a previously made product. Prescription diets are the only appropriate remedy for a suspected food allergy, and they are only available through your veterinarian.
I hope this has clarified any misconceptions about grain-free diets. If you are ever considering a switch in your pet's diet, always speak with your veterinarian first. Published by Dr. Vanessa Rucker, DVM