A recent story in the Washington Times cites results of a study published by the science journal Nature. The study indicates that dogs, unlike wolves, developed an early ability to easily digest starch.
This will not make grain-free dog food advocates happy
The study examined DNA from 12 wolves and 60 dogs. The results identified multiple areas where dogs differed from wolves in both brain function and digestion. One surprising difference indicated dogs had developed the ability to absorb starches and break down fats much more efficiently than wolves.
This ability came from the development of genes which govern the digestion of starch. Various copies of these genes are involved in how efficiently a particular food is digested. Dogs have up to 15 times more copies of this starch-digesting enzyme than wolves. Dogs now more closely resemble human digestion efficiency with this enzyme when compared to wolves.
The study supports one dog domestication theory
Results from the study appears to support the theory that dogs may have begun their domesticated split from wolves as they foraged at scrap heaps around human settlements.
This new food source changed as agriculture was in its infancy. It led to biological adaptation in both humans and dogs as diets evolved to include crops grown in fields. In other words, it may have been the grains in early doggie diets that helped their evolutionary split from wolves.
Does this mean that grain in dog food is now good?
Perhaps the question that should be asked is whether grain in dog food is bad. For grain-free advocates, the answer is clear. For others, the same rules of moderation and evaluation used for any food ingredient would apply equally to grains.
While ancient dogs may have been eating and adapting to grains, it most certainly was not their primary source of food. The theory holds that the dog- human bond may have grown out of sharing this new food source. It led to an increasing tolerance of grain in both species. It suggests that both dogs and humans may have evolved together in their ability to digest starch.
While far from conclusive, the study raises some interesting questions
It appears that early diets at the beginning of canine domestication may have had a large effect on helping the dog’s digestive system to adapt. Since wolves remained in the wild, their system was not exposed to the new foods, and did not evolve in the same way.
This same study identified differences in brain function between wolves and dogs, and those results are still being studied. This may further enhance our understanding of the differences between wolves and dogs. Most notably, how and when that split began.
Further research is underway to determine whether signs of these changes pre-date other evidence of early domestication. Results of that study may reinforce or contradict the theory supported from this recent study.
And so the debate continues. Grain or no grain. What’s in your dog’s bowl?