Are Fruits and Veggies Necessary?
One of the greatest controversies in the raw feeding world is the topic of fruits and veggies. Do they need them? Are they beneficial? We’ll address those frequently asked questions and why PMR feeders don’t believe they serve any purpose in the diet below.
Prey Model Raw (PMR) is guided with the ratio of 80/10/10. This means: 80% muscle meat including muscular organs (heart, tripe etc.) 10% edible bones, 10% secreting organs and add ons such as fish and eggs. These are all things that are conducive to a carnivores digestive system. Our canine companions share 99.8% DNA with their wolf ancestors and their digestive system is almost identical. It was once believed that wolves would eat the stomach contents of their prey. This theory however, that they need fruits and veggies because of the stomach contents has been disproved by many. In the book ‘Wolves: Behavior, Ecology, and Conservation’ by L. David Mech he states:
“Wolves usually tear into the body cavity of large prey and … consume the larger internal organs, such as lungs, heart, and liver. The large rumen is usually punctured during removal and its contents spilled. The vegetation in the intestinal tract is of no interest to the wolves, but the stomach lining and intestinal wall are consumed, and their contents further strewn about the kill site.”
“To grow and maintain their own bodies, wolves need to ingest all the major parts of their herbivorous prey, except the plants in the digestive system.”
Recent studies found some dogs have developed more Amy2b genes than wolves and therefore are better able to digest carbs. While this is true, the number of these genes is still small and differs between breeds. This is all due to domestication and human interference with their diet.
However, nothing else about our companions have changed:
Their molars haven't become flat. Their teeth are designed to rip through flesh and crunch through bones.
Their jaws haven't developed to move from side to side like herbivores. In fact, their jaws only move up and down.
They don't have salivary amylase to break down the cellular wall of veg.
Their GI tract hasn't elongated. Herbivores have an extremely long digestive tract giving the vegetables a chance to be broken down and the nutrients to be absorbed. Dogs however, have a relatively short digestive tract designed to get food in and out quickly.
You may have also seen the recent posts from the page Voyageurs Wolf Project on Facebook of wolves eating blueberries. There is nothing new or surprising about this, just interesting to see this on camera of course. Wolves are scavengers just like dogs and they eat fruit and berries when prey is scarce and they need to fill their bellies with something. In other words, this is starvation food and doesn’t provide any real nourishment. If you take a look at their scat, most of it comes out the other end undigested as wolves’ and dogs’ digestive systems aren’t equipped to digest these things well. There are clearly a lot less calories in berries compared to meat and also nutrients that the wolves can’t metabolize very well. When the wolves have to eat berries to fill their bellies, they are losing a lot of weight.
When it comes to carbohydrates which includes fruit, veggies, and grains there is no nutritional need nor requirement in the diet. Even the AAFCO and the NRC state this. As long as there is enough fat and protein provided for energy carbohydrates are not necessary.
“Thus, there appears to be no requirement for digestible carbohydrate in dogs provided enough protein is given to supply the precursors for gluconeogenesis.”-Nutrient Requirements for Dogs and Cats
Along with there being no nutritional requirement, feeding carbohydrates can actually cause more harm than good:
They don’t have a complete amino acid profile. A complete amino acid profile is needed to function properly.
They are missing some essential vitamins and minerals that dogs and cats need such as Vitamin D,Taurine,and Vitamin B12.
Carbohydrates have been shown to deplete Vitamin B and Vitamin C.
Carbohydrates raise the stomach pH above 5. Carnivores need their stomach pH to remain between 1-2 not only for the proper digestion of bone but to also kill off pathogens.
Can prevent puppies from growing and gaining weight properly
They don’t contain the right form of Vitamin A but a precursor to it (beta-Carotene). Humans and carnivores need the retinol form of Vitamin A, not the carotenoid forms. Retinol Vitamin A is found in fish oil, eggs, meat, liver and animal fats. It cannot be found in plant products. The body needs to convert carotene to retinol, a form of vitamin A that it can use.
They don’t have the right form of Omega 3 fatty acids. Plants contain the omega 3 fatty acid ALA. Dogs and cats require Omega 3s EPA and DHA. When an herbivore eats plants it can convert ALA to EPA and DHA. Your dog or cat cannot and therefore it must be provided in the diet by feeding oily fish, grass-fed and finished meat, whole prey, or by means of approved fish/krill oils.
Carbohydrates also have anti-nutrients. Anti-nutrients are plant compounds that reduce the body's ability to absorb essential nutrients. This can lead to health issues in both humans and in companion animals. These anti-nutrients include:
Goitrogens disrupt the production of thyroid hormones by interfering with iodine uptake in the thyroid gland. Although, a person can ingest plenty of carbohydrates containing goitrogens without having thyroid issues they should be avoided in a dog or cats diet. According to Dr. Jean Dodds thyroid issues are becoming an epidemic in our pets.
Goitrogens can be found in cabbage, cauliflower, brussel sprouts, broccoli, bok choy, kale, mustard greens, collard greens and turnips.
Lectins are carbohydrate-binding proteins and in large amounts can inhibit the body’s ability to absorb nutrients. They can also bind to the intestinal wall and cause a condition known as Leaky Gut Syndrome. Lectins are found in beans, wheat and nightshade vegetables such as; bell peppers, potatoes, and eggplant. Lectins are also suspected to inhibit the uptake of Taurine contributing to DCM.
Phytate (phytic acid)
Phytate reduces the absorption of minerals from a meal. These minerals include iron, zinc, magnesium and calcium. Phytates are commonly found in whole grains like oats, seeds, rice and legumes.
Just like phytic acid, oxalate acid also reduces the absorption of nutrients. On top of that, studies have shown that oxalate acid can exacerbate stone and urolith formation especially in those that already have a preexisting condition. Oxalate acid is found in many vegetables, fruits, and seeds. Including dark leafy greens like spinach and kale, cranberries, and sweet potatoes.
Tannins are considered nutritionally undesirable because they precipitate proteins, inhibit digestive enzymes, can affect the utilization of vitamins and minerals as well as cause damage to the mucosal lining of gastrointestinal tract. Tannis can be found in numerous sources including cranberries, strawberries, blueberries, apples, apricots, barley, peaches, dry fruits, pomegranate, raspberries, barley, rice, oats, among others.
Solanine is a chemical found in vegetables of the nightshade family( potatoes, eggplant, etc.) that can cause further inflammation in those with joint issues such as arthritis and can exacerbate allergy symptoms. Solanine is also found in fruits such as blueberries and apples.
Not only do carbohydrates contain anti-nutrients some are also extremely high in sugar.
Just like in humans this can cause hyperactivity; not the good kind of energy our pets would get from fat. These foods can also cause spikes in blood sugar levels in those that are diabetic, is the primary energy source for cancer cells, is what yeast feeds on, and can cause inflammation in the body and brain.
This breakdown of anti-nutrients isn’t meant to cause any sort of fear mongering. Anti-nutrients can be minimized by boiling, soaking and cooking the carbohydrates down. However, doing so will deplete the nutrients within them minimizing their benefits.
In the end to answer the question of do they need fruits and veggies? Are they necessary? Short answer: No