Yeast is an ancient substance that helped our nomadic ancestors settle down, spurring agricultural development and giving rise to civilization as we know it today. It is also a complete, clean and sustainable protein source for dog and people!

After you read our first blog post on the protein-packed power of yeast, you might be asking:

“Where the hell has yeast been all my life?!”

The answer? It’s been here all along! Unsung. Unappreciated. Just quietly and generously flourishing, waiting patiently for us to realize all of its wonderful qualities and living its best life in the meantime.

Reality is, yeast is an ancient substance. After all, yeast is a key ingredient in creating some of our most foundational food items: beer, bread, and wine. In fact, some theories float that yeast helped our nomadic ancestors settle down, by fields of barley and rows of grapevines, spurring agricultural development and giving rise to civilization as we know it today.

Because yeasts are fungi that grow in clusters of cells (as opposed to long, tubular chains) and fungi have been around since our primordial soup days, yeast has developed some distinct evolutionary advantages. It reproduces at a mind-bogglingly fast pace, gorging itself on sugar until it ends up as a nutrient-rich organism.

As a result of these factors – its role in creating some of our favorite foods and its ability to thrive -- yeast has become ubiquitous throughout nature, culture, and diet.

Because yeast is ever-present, it follows that somewhere along the way, our canine companions also got a taste for yeasty goodness. If we look at the history of our relationship with domesticated animals, it makes sense. Back in the day, meat was far too precious of a luxury to feed to animals[1]. Our canine companions were happily chowin’ down on leftover grains, the bottom of the veggie stew pot, and other miscellaneous sundries. It was only when industrial farming matured as an industry, and society enjoyed increased affluence overall, that we began feeding dogs meat on a regular basis[2].

This somehow got tied with the notion that our dogs, as descendants of predators in the wild, are meant to eat a diet primarily composed of meat and that this the “healthiest” option because it is in alignment with their wolf ancestors.

This narrative totally excludes the fact that there’s a world of difference between a freshly slaughtered rabbit, eaten within moments of the kill, and livestock pumped with unnatural antibiotics and hormones, processed beyond recognition and packaged into bags picked up off the supermarket shelves.

Similarly, a dog that spends half the day lounging at home while their owner is at work and a wolf hunting and scavenging all day in the forest are going to have vastly different nutritional requirements. In 2018, the Association for Pet Obesity Prevention found that an estimated 60% of cats and 50% of dogs in the US were overweight or obese, a sign that their diet is imbalanced for their actual energetic needs. High-meat diets have also been associated with kidney disease, liver disease, and cancer[3],[4],[5],[6],[7],[8],[9],[10],[11].

Pure meat-based diets are making our dogs unhealthier – because it’s simply not the optimal way for them to receive nutrition.

For example:

Dogs can convert plant-based beta-carotene (provitamin A) to retinol, the purest form of vitamin A. True carnivores obtain retinol from animal sources or supplements[12].

Dogs have more copies of the AMY2B gene, which produces amylase, a starch-digesting enzyme, and amylase activity is 30x higher in dogs than in wolves.

Another starch-digesting enzyme, maltase, is also far more active in dogs than in wolves, and is primarily found in herbivores and omnivores[13].

Trust us – you’re not somehow violating some ancient biological creed by feeding your dog a plant-based diet. Eating a plant-based diet is a dog’s ancient biological creed. They’re built for it, and it is a testament of how humans, domestic animals, and (yep, you guessed it!) yeast, have evolved in harmony throughout time, to rely on one another for basic survival needs.

References

[1]: https://www.petfoodinstitute.org/pet-food-matters/nutrition-2/history-of-pet-food/

[2] http://www.beard-redfern.com/bernerboris/can_nut.html

[3] Phillips-Donaldson, D. (2018). Pet food protein: How much is too much? Adventures in Pet Food. Pet Food Industry. Available at: https://www.petfoodindustry.com/blogs/7-adventures-in-pet-food/post/7231-pet-food-protein-how-much-is-too-much

[4] Böswald, L. F., Kienzle, E. & Dobenecker, B. (2018). Observation about phosphorus and protein supply in cats and dogs prior to the diagnosis of chronic kidney disease. Journal of Animal Physiology and Animal Nutrition, 102, 31-36.

[5] Hyogo, H. & Yamagishi, S. (2008). Advanced glycation end products (AGEs) and their involvement in liver disease. Curr Pharm Des, 14, 969-972.

[6] Osher Center for Integrative Medicine (UCSF). Animal Protein and Cancer Risk. Available at: https://osher.ucsf.edu/patient-care/integrative-medicine-resources/cancer-and-nutrition/faq/animal-protein-cancer-risk

[7] Greger, M. (2016) Animal protein compared to cigarette smoking. Nutrition Facts. Available at: https://nutritionfacts.org/video/animal-protein-compared-cigarette-smoking/

[8] Snyderwine, E. G. & Schut, H. a. J. (1999). DNA adducts of heterocyclic amine food mutagens: implications for mutagenesis and carcinogenesis. Carcinogenesis, 20, 353-368.

[9] National Cancer Institute. Chemicals in Meat Cooked at High Temperatures and Cancer Risk. Available at: https://www.cancer.gov/about-cancer/causes-prevention/risk/diet/cooked-meats-fact-sheet

[10] Van Rooijen, C. et al. (2013). The Maillard reaction and pet food processing: effects on nutritive value and pet health. Nutr Res Rev, 26, 130-148.

[11] Becker, K. (2017). What’s Wrong With Feeding Fresh Food to Your Pet? Healthy Pets. Available at: https://healthypets.mercola.com/sites/healthypets/archive/2017/05/22/feeding-pets-fresh-food.aspx

[12] https://www.dsm.com/markets/anh/en_US/Compendium/companion_animals/vitamin_A.html

[13] Arendt, M. et al. (2014). Amylase activity is associated with AMY2B copy numbers in dog: implications for dog domestication, diet and diabetes. Animal Genetics, 45, 716-722.