Read this...but don't stop there

Feed Your Pet Right

I admire Dr. Marion Nestle so much it borders on hero worship. Reading her blog once a week helps keep me sane in a world full of haters on science. I'm overwhelmed by the amount of research and skepticism she and Dr. Nesheim put into this book. Here are just a few of the club-on-head moments it presented me with:

- Dogs aren't wolves. They have been eating human leftovers for as long as they have been dogs. Grains, fruits and vegetables won't kill them--old recipes for feeding your dog include sea biscuit, Scotch oatmeal, and fine flour as a supplement to the butchers scraps.
- Cats diets haven't been documented in history very often, but it was always assumed they'd supplement whatever food man gave them with yummy raw mice. That's why we put up with them, after all. (my note)
- The pet food industry is huge, profitable, and just as complexly convoluted as the human food industry.
- Veterinarian training and day-to-day success is highly subsidized by the pet food industry. The potential for conflict of interest is huge.

This book is very valuable for those and many other reasons. And yet....

It's a little dated. For one example, she states that according to the current research of the time, dogs originated "12,000 years ago at about the same time that humans were beginning to establish agricultural settlements." We have since determined--and are still testing--that more likely it was 15,000 to 30,000 years ago or even earlier. The oldest fossils and DNA crunching indicates that dogs became domesticated while man were still mostly hunter-gatherer groups.

It lumps all grains together and doesn't take into account the huge change in grain crop genetics that started in the early 1950s and goes on to this day. Today's wheat is not our great-grandfather's wheat. Neither is corn, and there's an increasing body of anecdotal evidence that corn or the contaminants in corn may cause allergies in dogs. And when did soybean meal come into the picture? I doubt if our 12,000-year-old ancestors fed soybeans to their dogs.

And how about this final advice: [just like for human diets] As long as the diet includes sufficient amounts of a variety of minimally processed foods--meat, dairy, fruit, vegetables, grains (or their substitutes)--the needs for essential nutrients and energy will be met.

That says only what it says. If you're concerned about your pet getting enough nutrition, and if you can swallow the howler about "minimally processed", pretty much any pet food is okay. But since when was enough, the whole picture? Human beings can eat preserved meat and benefit nutritionally, but it's currently classified as a carcinogen.  We can use the sugar in soda for energy, but is it health-promoting?

And going back to the minimally processed question, how about this:

You mix ("precondition") ingredients to the right consistency, and force the mix through shaping dies....the processes involve heat and pressure, extrusion cooks the food, kills contaminating microorganisms, and gelatinizes the starch so it is easier to digest. After extrusion, the kibbles are dried. Now the fun begins. The maker sprays the kibbles with additional fat, protein digests, flavor additives, and antioxidants, and gives them another round of drying. At last, the dry foods are packaged, labeled, and shipped.

Here is the result from a human study (the NutriNet-Sante cohort study), describing a link between cancer rates and ultra-processed food.
Industrial processes notably include hydrogenation, hydrolysis, extruding, moulding, reshaping, and pre-processing by frying.