This week Health Canada banned the use of partially hydrogenated oils (PHOs), the main source of trans fats in our food. I'm obviously one of those 'all foods fit' dietitians. But this man-made ingredient was literally a recipe for disaster when it was introduced in 1911, in the form of Crisco shortening.
A Brief History
Partial hydrogenation is the process of adding hydrogen molecules to oils until they turn solid at room temperature. This discovery became particularly useful during WWII when butter was in short supply. POH products like Crisco and margarine were more affordable, and improved the shelf life and texture of products. They were widely used in baked goods, frosting, crackers, deep-frying and microwaved popcorn.
When we (prematurely) announced that saturated fats were the enemy in the 50s, people switched from butter to margarine to protect their heart health. Ironic knowing what we know now.
How Trans Fats Break Our Hearts
In the 90s several studies found that trans fats in PHOs increased bad cholesterol (LDL) and heart attack risk. We have since found it also reduces our levels of good, protective cholesterol (HDL).
When oils are partially hydrogenated they take on a trans configuration, vs the usual cis form. This unique structure is uncommon in nature and it interferes with our metabolism of omega-3 fats, the kind that protects us from heart disease. Here is an illustration using blue donuts as carbon and pink donuts as hydrogen molecules.
There is no safe level of trans fat intake.
The Ban Will Work
Canada and the U.S. made labeling of trans fats mandatory in 2002. Fast food chains and food manufacturers then voluntarily removed trans fats from their products. They were eager to take advantage of marketing a 'trans fat free' claim. Intake by the average American decreased from about 4.6g/day in 2003 to 1.3g/day in 2010.
Fast forward to 2015. The U.S. finally removed PHOs from the list of ingredients 'Generally Recognized as Safe'. Canada followed suit this week. All POHs are now illegal in Canadian food products.
It's estimated in the U.S. that 10,000 to 20,000 heart attacks will be prevented per year thanks to the ban.
When New York municipalities made the local decision to ban trans fats in 2008, it took about 3 years for heart attacks to start decreasing in a noticeable way. Hospitalizations were reduced by 6.2% and mortality by 4.5%.
Denmark was the first country to ban trans fats in 2002. They also saw cardiovascular related deaths drop by 14.2 deaths per 100,000 Danes.
How will this affect our food?
Canada's margarine and oil industry basically phased out trans fats a while ago. The products have the same texture and taste but with better nutrient profiles.
No food requires the use of PHOs. They can easily be replaced with a number of other delicious ingredients, but likely at a high price point and shorter shelf life. Overall, I don't think anyone will notice.
Take care of your hearts!