Disturbing research published in the New England Journal of Medicine has found that people who regularly succumb to processed foods like burgers, fries, biscuits, pies, pastries and certain margarine spreads can easily consume high levels of trans fats (10-25 g per day), now recognised to be four to five times more harmful than even saturated fats in promoting heart disease! Consuming 5 g trans fats daily is known to increase heart disease risk by 25 per cent. Yet it's possible to eat 30 g in just one meal if you choose certain chicken nuggets, French fries, wafers and microwave popcorn.
Why are they so bad?
Apart from increasing harmful LDL-cholesterol while lowering the protective HDL type, trans fats promote insulin resistance, type 2 diabetes, and may contribute more to weight gain than other types of fats! They also cross the placenta and escape into breast milk and have been linked to reduced birth weight and brain size in babies.
Where are they found?
Most trans fats eaten today are manufactured by the food industry, which uses a process called hydrogenation to harden vegetable oils, prolonging their shelf life and giving them a characteristic that makes snack foods more crisp and fried foods less soggy.
A smaller amount of trans fats come from meat and dairy products, especially ruminant animals such as cattle, goats and sheep.
The US National Academy of Sciences Institute of Medicine suggests there is no safe level of trans fat and that we should eat as little as possible. Some experts recommend less than 1 g per day.
How do I avoid them?
The US and Canada require labelling of trans fats. Denmark now limits the amount allowed in foods so it is nearly impossible to consume more than 1 g on a daily basis. However, there is no mandatory requirement to declare trans fats in Australia and New Zealand unless a claim is made about cholesterol or other fats present.
Tip: Avoid fried takeaways, processed snack foods, full-cream dairy products and fatty meats. While some margarines have been reformulated, certain less expensive brands may still contain high levels. Avoid any food with partially hydrogenated vegetable oil in the ingredient list.