Food scores are based on ingredient quality and safety. For more information, view our evaluation criteria.
With a score of 1.6/10, Purina One Dry Smartblend is considered a very high risk dog food based on our criteria. There are 9 recipes that average 27% protein and 36% carbohydrate as calculated.
These recipes are high in carbohydrates and include grains and starches, including several types of corn products, wheat, soybean, rice, rice flour and brewers rice within the first 5 ingredients. Dogs have no nutritional requirement for carbohydrates but starch is required for extrusion in dry foods. Excessive carbohydrate is an indicator of lower food quality as it can be used to reduce manufacturing cost. Foods that are high in carbohydrates can increase insulin levels, increase the risk of obesity and cause unwanted changes to the gut microbiome.
Also high on the ingredient list are plant proteins like corn gluten meal, soybean meal and oat meal which also contribute to the high carbohydrate level. Plant proteins are a less expensive substitute for quality animal protein. You want to see animal sources because they’re more digestible and contain a wider array of amino acids than plant based protein sources.
This line is lower in protein, and the fact there are added amino acids can reflect lower quality protein that doesn’t provide these nutrients naturally.
An excessive amount of vitamins and minerals have been added to meet nutrient requirements in these recipes. This usually reflects poor quality or overly processed ingredients. Vitamin and mineral excesses, especially vitamin D and copper, can also result from added vitamin premixes, so it’s preferable that most or all vitamins and minerals come from real foods.
It’s also worth noting that the line contains sodium selenite as a source of selenium. Dogs need selenium, and it’s usually added in very small amounts. However some research suggests that sodium selenite may be associated with potential toxicity, so selenium yeast is the preferred form of this mineral.
Another quality concern is the use of glycerin, which is a sugar often found in pet food to increase food palatability, or as a preservative or humectant. It is a low quality ingredient that can cause unwanted gut changes, obesity and insulin spikes.
Soybean oil is an inflammatory seed oil that is highly processed and may contain trans fats. Studies show that ultra processed foods are linked to a higher rate of all-cause mortality in humans. Vegetable oil is also listed and it’s noted as a source of MCT oil and yet the source isn’t specified. MCT oil is found in palm oil and in low amounts in coconut oil.
For those choosing this line for its single protein recipes, it should be noted 4 of the recipes combine 2 or more proteins. The Healthy Weight recipe has turkey with chicken by-product meal, the Healthy Aging Formula has chicken with fish meal, the Small Breed Formula has beef and poultry by-product meal and the Puppy Formula has lamb with a poultry by-product meal. Fish meal and poultry by-product meal are unnamed animal proteins that can further complicate the search for a single protein food. Unnamed animal ingredients are a sign of low quality and can be made from any type or types of fish or poultry. Unnamed animal ingredients are often a less expensive, low quality ingredient that can be made from rendered waste of many proteins.
Fish meal is also listed as a source of glucosamine but as the type of fish isn’t named it’s difficult to determine the amount or quality of the glucosamine available.
There doesn’t seem to be much difference in the ingredients and guaranteed analysis of the Healthy Weight and Healthy Aging dog foods to the other recipes in this line. Healthy Weight is a bit lower in fat, but actually has the highest level of 41% carbohydrates as calculated, which can actually lead to weight gain and insulin resistance. The Digestive Health recipe has the same low level protein and high carbs but with the addition of probiotics with a guaranteed amount.
On the ingredient safety side, 7 of these 9 recipes score 0/10 which is concerning, and the recipes don’t fare much better. The concerns begin with kibble being an ultra processed dog food, which costs a loss in points across the line. The individual ingredients in dry dog foods are heated several times during processing, which can cause a significant loss of enzymes, vitamins, amino acids and phytonutrients. Processed foods are also linked to higher mortality rates in many species.
These recipes also use ingredients known to contain higher pesticide/herbicide residues, like wheat in the top 5 ingredients. Crops that are spray-dried with Roundup contain more glyphosate/herbicide residue than other crops, even genetically modified ones. Glyphosate is an antibiotic that can kill beneficial gut bacteria and has been linked to cancer and other diseases.
Corn and soybean meal are GMO crops included in the top 5 ingredients of each recipe. There are limited safety studies on genetically modified and Roundup Ready crops, although they are lacking in nutrients compared to non-GMO foods. GMO crops also strip nutrients from soils, cause increased pesticide risk and may be involved in bee die-off.
Recipes in this line contain natural flavor, which is added to make processed food more palatable. But natural flavor is often either MSG or animal digest, both low quality ingredients with limited safety studies.
The use of rice in several recipes costs ingredient safety points because of potential arsenic contamination. This is a significant concern with rice since it naturally absorbs arsenic that can contaminate the water it’s grown in. Arsenic is linked to chronic health issues.
Caramel color has been added to these foods. It’s often added to make them look more appealing to consumers. They are often used to hide the grey color of rendered ingredients and are linked to health issues.
Lastly, these recipes contain menadione, a synthetic form of vitamin K that is not required in dog food. It may be linked to immune system dysfunction, oxidative damage to cells, liver toxicity, and allergic reactions.
These concerns don’t cost points but are worth noting.
There is ingredient splitting in these recipes. That’s the practice of splitting ingredients into subcategories to make them appear lower on the list. This can also move more desirable protein ingredients higher.
These recipes also glam ingredients which is when expensive or desirable ingredients are added to appeal to consumers but may be in miniscule amounts. If these foods are below salt or other low concentration ingredients, they contribute little or no nutritional value for your dog. In this case carrots and peas are added which are the only vegetable ingredients, so it would have been good to see them higher to contribute more nutrients.
These recipes don’t specify whether fish products are from farmed or wild caught fish. Farmed fish is less nutritious than wild caught fish and does not contain the same healthy fatty acid balance.
Lastly, Purina doesn’t provide the omega-6:omega-3 ratio, which is a concern since AAFCO allows a very inflammatory ratio of 30:1.
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