Today, Canada will become the first country in the world to introduce mandatory nutrition labelling of trans fats for most packaged foods. As a researcher devoted to cardiovascular health, I welcome this new legislation with enthusiasm because it has great potential to improve the health of Canadians.
What are trans fats? What impact do they have on health? Where are they found? The majority of trans fats in our diet originate from an industrial process called partial hydrogenation, which solidifies liquid vegetable oils to make them more stable to heat and extends shelf life of the product into which they are introduced.
Unfortunately, these industrially created trans fats have major effects on human health. Many studies conducted in very large populations around the world have shown that, gram for gram, industrial trans fats may be 10 to 12 times worse than saturated fats when it comes to increasing the risk of heart disease. Like saturated fats, industrially produced trans fats increase the bad (LDL) cholesterol in the blood.
However, unlike saturated fats, industrially produced trans fats reduce the good (HDL) cholesterol levels. They also promote the accumulation of smaller LDL particles in the blood, which are particularly damaging to our arteries. Trans fats may even disrupt the elasticity of the arteries, a phenomenon called endothelial dysfunction, which also contributes to an increased risk of heart problems.
Industrial trans fats are typically found in commercial baked goods, snack foods, deep-fried foods, partially hydrogenated margarine and vegetable shortening. The average consumption of industrially produced trans fats in the Canadian population has been estimated to range from five to 10 grams per day. And trans fats can actually add up quickly when one relies a great deal on commercially prepared foods. A doughnut and a coffee in the morning, an order of large fries for lunch, and a large portion of popcorn at the movies add up to 20 grams of trans fats in any given day!
We as Canadians have to pay particular attention to our intake of trans fats because we are among the world's largest consumers of these fats. Our average daily intake has been estimated to be about four times more than people living in Greece, Italy and France.
It must be stressed that very small amounts of trans fats also occur naturally in the fat of ruminant animals. These trans fats are naturally produced in the stomachs of cows, goats and sheep and subsequently end up in very small quantities in dairy products and red meat. The impact of naturally occurring trans fat on health has not been well documented to date. Interestingly though, data from the few studies that have been conducted on this issue suggest that, unlike industrial trans fats, natural trans fats may not be associated with health problems.
The consumption of much smaller quantities of naturally occurring trans fats, compared to industrial trans fats, also suggests that they are unlikely to have undesirable effects on health. Nevertheless, further research is undoubtedly required to shed more light on the subject of naturally produced, versus industrially produced, trans fats and their apparently different effects on health.
The good news is that the new Canadian regulation on mandatory trans fat labelling has already prompted many food companies to reduce or even eliminate industrial trans fats in their products, therefore improving the quality of foods available at the supermarket. As a result (and thankfully), the intake of industrially produced trans fats has been declining over the past few years in Canada.
However, industrial trans fats continue to lurk in many commercially prepared foods, particularly in foods from fast-food venues and restaurants, which are not yet subjected to mandatory labelling. Arguably, the most appropriate level of intake of industrially produced trans fats would be zero. Consumers need to be vigilant about the food they eat. At the individual consumer level, there remains a huge need for continuing education on the sources of industrial trans fats in our diet and their effects on health.
Countries such as Denmark have been very proactive and successful in forcing the trans fats out of their diet. While the Canadian food industry will certainly have to put up with additional costs for replacing trans fats in its food products by healthier alternatives, I have no doubt these costs will be greatly surpassed by the resulting benefit on human health. We will be far better off if industrial trans fats are eliminated from our foods.
Benoît Lamarche, director of the Institute on Nutraceuticals and Functional Foods at Laval University, Quebec, is a Canada Research Chair in nutrition and cardiovascular health.
