What follows is a true story. It really happened, and you should draw your own conclusions.

Many years ago, my daughter and I ventured out on a snowy evening in January and brought home the sweetest, gentlest, eight-week-old Labrador Retriever puppy. We named our new chocolate lab Mousse. Mousse played ball; Mousse cuddled with the children; Mousse helped me weed the garden; Mousse stole food from the kitchen table when she thought no one was looking; Mousse hung out with the chickens and enjoyed visiting with our friends and neighbors, both human and canine. Mousse became family, and all was well.

When Mousse turned ten years later, I noticed that her coat wasn’t quite as shiny, and she was starting to get some dandruff. We decided to begin adding canola oil to the duck-and-potato kibble that Mousse had been eating since she was two. Why canola? We picked canola oil primarily for the economics. It seemed silly to buy high-quality oil for a dog, even Mousse. I wasn’t exactly sure how I felt about canola, but it seemed a reasonable compromise. And why duck-and-potato kibble? It turned out to be the most reliable way to get rid of the chronic ear infections from which she suffered when she was little.

After a few weeks of canola oil, the dandruff began to disappear and Mousse’s coat became shiny again. She was getting older, though, and definitely a little stiffer, especially in the mornings.

Then there was a big sale at the supermarket and we decided, on a whim, to try corn oil instead of canola. Just like with the canola oil, we poured a couple tablespoons of corn oil on Mousse’s kibble every day. Within days, she was so stiff that she could barely propel herself up and out in the mornings. Climbing stairs became out of the question. We were horrified. This situation called for drastic action.

We switched immediately to olive oil, hoping it would help her joints heal, and that is exactly what happened. Within a couple weeks, her joints were flexible again. She was rising easily in the mornings, and she didn’t seem to be in pain anymore. We were thrilled. It felt like magic. Although she didn’t heal completely — she no longer climbed the stairs to the second floor, for example — she was, for the most part, back to normal. 

At this point, we switched back to canola oil, promising ourselves never to use corn oil again. But what happened next shocked us: Within just a few days, Mousse’s joints began to stiffen up again. Though it was not as dramatic as it had been following the addition of corn oil to her diet, it was clear to us that things were worsening once again. We went back to the olive oil, and once again she healed. We gave the canola another try, and once more she became stiff. We returned to the olive oil, once and for all.

Here is what you need to know about products like corn oil. Corn oil is high in omega-6 fatty acids, which are strongly pro-inflammatory. Just as we need omega-3’s to reduce inflammation in our bodies, we need omega-6’s to cause inflammation, to help our immune system fight foreign invaders. It’s a balance, which we get exactly right when we eat corn on the cob, whole-grain corn meal, and the like. It’s the same scenario with soybean oil: Edamame, tofu and miso provide exactly the right balance of omega-6’s and omega-3’s, but commodity-based seed oil products, like corn oil, soybean oil, “vegetable” oil and, most especially, cottonseed oil, are sky-high in the omega-6’s that increase inflammation.

Until this experience with our beloved chocolate Mousse, I reserved judgment on “canola” oil, an acronym of sorts derived from CANadian OiL Association. But not anymore. Whatever canola oil is, it no longer has a place in my kitchen. And I no longer wonder if corn oil is having a negative effect on the health of my friends and patients — to me, the answer is clear.