A Harvard Health Blog entitled “10 Superfoods to Boost a Healthy Diet” arrived in my inbox this week. I have to say I was a little surprised to see that olive oil made the list. Are you confused about whether we should be loading up on olive oil or skipping it altogether? Do you see all the mixed messages that I see?
I recently heard Joel Kahn, MD talk about the olive oil controversy. Dr. Kahn is a Detroit-based holistic cardiologist who promotes plant-based eating within his practice and beyond. For his patients trying to reverse major cardiac disease he recommends avoiding olive oil and refers them to the book Prevent and Reverse Heart Disease by Caldwell Esselstyn, MD. He does this because the only researchers who have demonstrated the reversal of heart disease had their study patients on a no-fat plant-based diet. This includes Dr. Esselstyn, Dean Ornish, MD, Nathan Pritikin, PhD and others. Dr. Esselstyn draws a hard line on oils (see here). This is in part because some small studies (example here) that have shown that, shortly after consumption, oils have a detrimental effect on the cells that line our blood vessels, which can impact their ability to relax and dilate normally.
Dr. Kahn also thinks it makes good sense to avoid olive oil if we struggle to achieve a healthy weight and/or we have type II diabetes and are trying reverse insulin resistance. Oil generally contains a lot of calories and very few nutrients due to the processing of the whole food (olives). For all the calories, oil doesn’t make us feel full which usually means we’ll keep eating. These are some of the reasons Dr. Michael Greger considers oil a “yellow light food”, which means we should consume it minimally, regardless of our health status. We can instead fill up on unprocessed plant-based food packed with nutrients that both nourish us and satisfy our hunger.
For those of us who aren’t struggling with advanced heart disease, weight issues or type II diabetes, Dr. Kahn believes a small amount of good quality extra-virgin olive oil or organic (non-GMO) canola oil is acceptable. This is the approach I take. I use oil minimally for the purpose of enhancing the flavours and textures of those foods we know for sure are nutritional powerhouses: fruits, vegetables, legumes, whole grains, nuts and seeds…so that I’ll eat even more of them!
So is olive oil a superfood or a toxin? I’m certainly open to the fact that it may become evident in the years to come that certain oils processed in certain ways do indeed have beneficial effects for certain people. I believe there remain many unknowns but that based on what we know so far, it’s unlikely the title of “superfood” will ever be justified for our population at large.