US bans 'unsafe' trans fats in food: 5 things to know about trans fats

A pie and a block of margerine, which both contain trans fats.
A pie and a block of margerine, which both contain trans fats.PHOTO: AFP

Food industries in the US will have three years to rid their foods of trans fats, as the Food and Drug Administration (FDA) took a major step towards eliminating the use of partially hydrogenated oils that have long been linked to heart disease and fatal heart attacks.

The new ruling, which FDA released on Tuesday, requires companies to cut out trans fats from food by 2018.

Artificial trans fats found in everything from margarine to cookies and frozen pizzas are not safe to eat, the US regulator said.

1. What are trans fats?

Most trans fats are formed during the process of hydrogenation of vegetable oils - an industrial process which converts liquid oil into solid fat.

It is mainly used to prolong the shelf life of food products and ensures food such as cookies stay crispy.

French chemist Paul Sabatier won the 1912 Nobel prize in Chemistry after he discovered the hydrogenation method, while German chemist Wilhelm Normann is credited as the inventor of trans fats.

2. Which foods contain it?

It is present in margarine, cooking oil, cake shortening, pies, ice cream and cookies. Deep-fried foods also contain high levels of trans fats.

Small amounts of natural trans fats can also be found in beef, mutton and diary products. It occurs naturally in the milk and body fat of cows and sheep and is not considered harmful.

3. How is the artificial version harmful?

Research has shown that it is currently one of the worst kind of fats for the heart, even more harmful than saturated fats, which raises bad cholesterol.

Trans fat reduces a body's good cholesterol that in turn increases the risk of heart disease. It blocks up the arteries that lead to the brain and heart, resulting in heart attacks and strokes.

Scientific studies conducted by the US in the early 1990s showed that it increased the risk of coronary heart disease, with Americans' trans fat intake averaging four to seven per cent of their calorie intake.

4. Are trans fats allowed in foods in Singapore?

New limits imposed in May 2012 on food makers, cooked food outlets and supermarkets in Singapore require that trans fat in all margarine, cooking oil or shortening be limited to no more than 2g per 100g.

This is also the limit recommended by the World Health Organisation (WHO). Denmark was the first to introduce the 2g cap in 2004, which was followed by countries such as South Korea, Brazil, and the Netherlands.

According to statistics released by the Health Promotion Board that year, three in 10 persons here consumed over the daily recommended limit due to them eating out more often and snacking on fried foods. WHO recommends that the daily intake of trans fats should not exceed 1 per cent of total calories.

5. What can one do to reduce intake of trans fats?

When cooking at home, the Health Promotion Board recommends using less oil in cooking and adopt healthier cooking methods such as baking and steaming.

Spreads such as margarine, butter and kaya should be used sparingly.

Those who eat out should limit their consumption of fried foods and high-fat bakery products such as pastries and cakes.

SOURCES: The New York Times, CNN, Singapore Heart Foundation, The Straits Times archives, Health Promotion Board