Dr. Dean Ornish answered:
Because canola oil has significant amounts of omega-3 fatty acids, whereas, olive oil does not. The omega-3 fatty acids are truly good fats for most people. They have extraordinary health benefits.
The omega-6 fatty acids are also essential to your diet. The problem is that most Americans consume too much of the omega-6 fatty acids and not enough of the omega-3 fatty acids. While the omega-3 fatty acids reduce inflammation, the omega-6 fatty acids increase it if you consume too much of them. Inflammation increases the risk of coronary heart disease and other chronic illnesses.
Ideally, the ratio of omega-6 fatty acids to omega-3 fatty acids should be about 1 to 1, or no more than 2 to 1. Unfortunately, the ratio in the average American diet (and now that of much of the rest of the world) is between 10 to 1 and 30 to 1, which means most people are consuming way more of the omega-6 fatty acids than the omega-3 fatty acids. The best way to improve this ratio is to consume more omega-3 fatty acids and fewer omega-6 fatty acids.
Much of the excessive omega-6 fatty acids come from eating the wrong kinds of oils. Although olive oil has the reputation of being “good for you,” it has thirteen times the amount of harmful omega-6 fatty acids as beneficial omega-3 fatty acids. Corn oil is even worse, with a 46 to 1 ratio of omega-6s to omega-3s.
On the other hand, canola oil has a much more balanced ratio of 2 to 1 omega-6s to omega-3s. Flaxseed oil is rich in omega-3 fatty acids, with a ratio of 1 to 3 omega-6s to omega-3s.
So, to improve your ratio, consume more canola oil or fish oil (which contain omega-3 fatty acids) and less olive oil. This doesn’t mean you should never have olive oil - I like the taste of olive oil, and I enjoy it sometimes. It’s a healthier fat than many others, but it’s not nearly as healthy as fish oil, canola oil, or flaxseed oil.Find out more about this book: The Spectrum: A Scientifically Proven Program to Feel Better, Live Longer,...Because canola oil has significant amounts of omega-3 fatty acids, whereas, olive oil does not. The omega-3 fatty acids are truly good fats for most people. They have extraordinary health benefits. The omega-6 fatty acids are also essential to your... More