View Full Version : Research: dog diet evolved beyond meat to grains/starch, very early on

29th January 2013, 12:37 PM
This is really interesting research -- which in part shows that dogs developed the ability to digest grains early on. Not an argument that dogs should get a cereal-full diet -- but does suggest that a firm 'anti-grain in dog food' stance -- which gets a lot of mileage on the internet!! -- is actually misguided and that intolerance for grains in dog food is likely, not a common issue at all. Here's a WebMD blog post, passed along by Telegraph columnist Pet the Vet. The blog post is easy to understand and is very balanced in suggesting the directions one could go with feeding -- and cautioning strongly against most dog foods that simply contain poor quality feed grade ingredients:


Interestingly, genetic sequencing shows that dogs have a number of genetic changes in their genome that enables them to digest grains and starch and thus benefit from their vitamins and minerals.

a study published in Nature magazine proved that dogs’ domestication complements environmental and geographical changes associated with their role as companions to humans. It’s proven in their genes, which have evolved similarly to man’s and reflect dogs’ ability to digest grains and starches.


“Ten genes with key roles in starch digestion and fat metabolism also show signals of selection. We identify candidate mutations in key genes and provide functional support for an increased starch digestion in dogs relative to wolves. Our results indicate that novel adaptations allowing the early ancestors of modern dogs to thrive on a diet rich in starch, relative to the carnivorous diet of wolves, constituted a crucial step in the early domestication of dogs."

Even though today’s dogs can digest grains and starches, I don’t recommend that such nutrients form the majority of a dog’s diet. Any grains or starches made to be consumed by our pets should be whole-food based, cooked, and included in a small to moderate quantity (30% or less of the volume of a particular meal), complementing the larger percentage of meat, vegetable, and fruit ingredients.

Although commercially available and home prepared diets that are 100 percent free of grains and starches are popular, there are nutritional benefits stemming from their inclusion. Whole grains like brown rice, barley, etc., are good sources of minerals (Selenium, Manganese, etc.) and can even serve as substrates (pre-biotics) on which beneficial bacteria (pro-biotics) grow. Starches like russet and sweet potatoes, banana, etc., are rich in vitamins (A, B6, E, etc.) and minerals (Potassium, Manganese, etc.).

This research is ironic in timing, as an Irish distributor of (excellent) raw food just wrote a booklet arguing how dogs are almost entirely carnivores. This research suggests not. It also would not match research of various canid diets which showed that coyotes for example -- who would probably be similar to early domestic dogs in that they are opportune eaters and hang about close to human settlements, scavenging -- eat a certain amount of fruit etc.

29th January 2013, 02:17 PM
The big problem with the blog is that it assumes the research article "proves" something, while, at best, it might be evidence of some dietary evolution. It proves nothing, considering other research to the contrary, regarding the eating habits of feral dogs and wolves.

29th January 2013, 06:26 PM
Yep we might not agree on this one! :lol: I don't think one can argue with actual genetic changes that occur for metabolising grains and starch -- and it makes sense if dogs were living off scraps from human settlements, when humans would have been using grain and likely feeding dogs bread scraps. It doesn't take long for dietary evolution. Genetic change doesn't happen without a purpose; and there's no reason to conserve a change unless it confers an advantage. Being able to get nutritional value from a wider range of foods is a genetic advantage for animals who have become domesticated and are living with humans.

I think the post is not arguing a food nazi perspective however! :lol: It is actually fairly nuanced.

29th January 2013, 06:40 PM
But the article does not account for the results of other studies, to wit: those that have shown that feral dogs become predators with a preference for killing and eating small animals over nibbling on vegetation and grains, and that wolves occasionally will eat fruit, seeds, nuts and vegetation.

If this truly is a genetic evolutionary disposition, then dogs in the woods would not go to the trouble of killing other animals for food, and wolves, of course, would never have considered dining on fruit, seeds, and greens.