Canada’s ban on artificial trans fats comes into effect this week, one year after the federal government announced it would be ending the use of the artery-clogging fats.

The ban specifically prohibits adding partially hydrogenated oils, or PHO’s, to packaged foods and foods sold in restaurants.

For years, the oils were used in the production of baked goods because they extended a product’s shelf life. They were also used as frying oil for foods such as french fries. But research has repeatedly shown the fats can raise levels of bad cholesterol in the blood and lower levels of good cholesterol. The high consumption of trans fats is thought to be responsible for thousands of cardiac deaths in Canada every year, according to the Heart and Stroke Foundation.

What trans fats essentially do is increase levels of bad cholesterol (LDL cholesterol) and decrease levels of good cholesterol (HDL cholesterol), one dietitian told CTV News.

"The result of this is that they clog your blood vessels and an increased risk of heart disease and heart attacks," said Carol Dombrow, a registered dietitian with the foundation, in an interview with CTV News Channel Sunday.

"With the ban of trans fats what's being predicted is that we would save 12,000 people having a heart attack over the next 20 years," she said. "So it's very significant."

"Pastries and baked goods and commercially produced french fries, artificial dairy and creamers—those kinds of foods contain trans fats," she added.

According to the Heart and Stroke Foundation, those artificial trans fats increase bad cholesterol levels and result in clogging of the blood vessels. This doesn't seem to be true for the natural occurring trans fat found in meat and dairy products.

"It's going to make a big difference in the health of Canadians," Dombrow said. Heart and Stroke have been working with Health Canada since the latter formed the trans-fats task force in 2006.

Trans fats cause a three-fold increase in the risk of death from heart disease and the ban is expected to cut that risk down, said Manuel Arango, director of health policy and advocacy at the Heart and Stroke Foundation.

Cardiac anaesthesiologist Dr. Louise Sun, from the Heart Institute at the University of Ottawa, said the ban follows the notion that "the best medicine is prevention." She added that, while it's possible that this could lead to regulatory bans on other unhealthy substances, Canada has to come up with replacement products first, “So that we don't run into problems where the alternatives may be equally as harmful."

The food industry had been voluntarily phasing out partially hydrogenated oils for years, but the federal government never imposed a ban.

Instead, it introduced mandatory trans fat labelling, set voluntary targets for processed foods, and set up a monitoring program to measure industry’s progress toward meeting the voluntary targets.

Last year, after years of calls from health advocates for a total ban, Health Canada finally announced it was giving the food industry one year to phase the oils out completely.

Canada isn’t the first country to do this. Since Denmark first enacted a trans fat ban in 2003, Arango says the food industry has had time to develop "plenty of alternatives to replace trans fats."

The ban applies to all packaged foods produced in Canada, as well as imported products, and foods served in food service establishments.

"But some products made before today, they could be there up to two years later... in two years it'll be completely eliminated," Arango said. While people shouldn't taste many differences in their foods, the difference might be more noticeable in such products as croissants, for example.

"The government has made a decision that the shelf life of Canadians is more important than the shelf life of croissants," he said.

Those trans fats that occur naturally in some animal products are not part of the ban.