No doubt about it, the trend toward eliminating grains and substituting white potatoes or sweet potatoes in commercial and home-prepared foods for dogs is a source of controversy between dog caretakers, veterinarians, nutritionists and manufacturers. Still, more and more people continue to subscribe to the no-grain philosophy. Proponents of grain-free foods claim that ingredients such as sweet potatoes, white potatoes and other vegetables and fruits provide dogs with the healthy carbohydrates they need for a balanced diet. In addition to the grains-versus-potatoes argument, dog caretakers disagree whether white potatoes and sweet potatoes provide comparable nutritional value. If you're thinking about removing grains in favor of other carb sources, you might be wondering whether you should opt for sweet potatoes or white potatoes. Below, we'll examine the pros and cons of both.
White potatoes and sweet potatoes originate from two different plant families. White potatoes are from the Solanaceae family. The green areas of the peel and sprouts of a white potato contain solanine, a poisonous substance that, when eaten raw or cooked, may cause your dog to experience symptoms ranging from gastrointestinal disturbances to neurological problems. Sweet potatoes, members of the Convolvulaceae plant family, have no solanine, but they are not trouble-free. Vegetable gardens producing white potatoes or sweet potatoes present dangers for dogs. Moldy sweet potato plants may lead to serious respiratory distress, for instance; and ingested sweet potato vines can cause your dog to hallucinate.
Although the carbohydrate content of white potatoes and sweet potatoes is similar, eating white potatoes, which are high on the glycemic index, causes a dog's blood sugar to rise quickly. This should be avoided, especially for dogs with diabetes, because a spike in glucose requires the pancreas to release large amounts of insulin to lower blood sugar levels. Sudden fluctuations of blood sugar levels can lead to hyperactivity, nervousness, aggression and reactive or compulsive behavior in dogs. Sweet potatoes are lower on the glycemic index, which, along with their high fiber content, allows the dog's blood sugar level to rise more gradually, which is preferable.
Dogs suffer from some health conditions that can be exacerbated by eating sweet potatoes or white potatoes. Because white potatoes and sweet potatoes are high in carbohydrates and sugar, they can aggravate canine candida. White potatoes feed yeast, and this can cause or intensify yeast infections. Sweet potatoes are problematic as well, as they have more naturally occurring estrogen than white potatoes. High levels of estrogen in sweet potatoes may trigger or worsen food allergies and can be detrimental to any dog with a hormone antibody imbalance. Eating raw sweet potato is unsafe for dogs, because uncooked sweet potatoes contain a substance that inhibits trypsin, a natural enzyme necessary for the pancreas to digest proteins.
Vitamins and Minerals
Cooked white potatoes contain high levels of vitamin B-6, which provides mood regulation and helps your dog cope with stress. Sweet potatoes contain higher levels of vitamin C, vitamin D, iron, phosphorus and magnesium than white potatoes. Sweet potatoes and white potatoes are both good sources of potassium, a mineral that regulates fluid levels, nerve impulses and muscle contractions. Sweet potatoes are richer in calcium, which strengthens your dog's teeth and bones. White potatoes provide many of the same vitamins and minerals but in smaller amounts than are found in sweet potatoes.
The Center for Science in the Public Interest ranked sweet potatoes the most nutritious of all vegetables. Sweet potatoes contain higher levels of the antioxidant beta-carotene than most other vegetables. Receiving high marks for dietary fiber, natural sugars, complex carbohydrates, protein, vitamins A and C, iron and calcium, sweet potatoes earned 100 points more than white potatoes, the second place vegetable. Sweet potatoes are also natural stool hardeners that ease the discomfort of dogs who have diarrhea.
One promising benefit of white potatoes is that they are one of few foods containing blood-pressure-reducing natural phytochemicals called kukoamines. White potatoes are a good source of flavonoids and other "phenolic compounds that have a wide range of health-promoting properties, including antioxidant activity," according to USDA report contributor and plant geneticist Roy A. Navarre.
By Maura Wolf
VetInfo: Grain-Free Dog Food
Safe Spectrum: Potato Glycoalkaloid Toxicity: Solanine
ASPCA: Sweet Potato Vine
Los Angeles Times: Sweet Potatoes vs. White Potatoes: Are Both Bad for the Waistline?
Dr. Alfred J. Plechner: What You Need To Know About Today's Pet Foods
Center for Science in the Public Interest: Nutrition Action Healthletter - 10 Worst and Best Foods
Dog Breed Info Center: Basic Feeding Guide: Puppies and Adult Dogs
USDA Agricultural Research Service: Phytochemical Profilers Investigate Potato Benefits
About the Author
Maura Wolf's published online articles focus on women, children, parenting, non-traditional families, companion animals and mental health. A licensed psychotherapist since 2000, Wolf counsels individuals struggling with depression, anxiety, body image, parenting, aging and LGBTQ issues. Wolf has two Master of Arts degrees: in English, from San Francisco State University and in clinical psychology, from New College.