When you buy commercially baked goods such as pies, pastries, cakes and biscuits, there’s a good likelihood they’ll contain one of the nastier types of fatty acids: trans fats. These unsaturated fats have been chemically altered to give them a longer shelf life and withstand repeated re-heating.
Trans fats are produced through hydrogenation, a manufacturing process where hydrogen is added into the fatty acid structure of fats. This stabilises the oil, allowing it to remain solid at room temperature and to be turned into margarine and cooking fat.
Small amounts of trans fatty acids (trans fats) are also found naturally in dairy and meat products.
How big a problem are trans fats?
The first artificially produced trans fats date back to the early 1900s, when a German chemist found a way to turn liquid oils into solid fats.
Trans fats were initially thought to be a healthy alternative to saturated fat, particularly after the 1950s, when alarms were raised about saturated fats.
But by the 1990s the evidence indicated otherwise. Trans fats were linked with elevated LDL (bad cholesterol) and reduced HDL (good cholesterol), leading to an increased risk of heart disease.
The World Health Organisation recommends less than 1% of a person’s total energy intake be derived from trans fats.
The United States Food and Drug Administration (FDA) estimated Americans' intake of trans fats in 2012 was an average of 1g per person per day, or 0.5% total energy.
Phase-out in the US
The United States introduced mandatory labelling of trans fat content in foods in 2006. In June 2015, the FDA determined that partially hydrogenated oils were not “generally regarded as safe” for use in human food.
The evidence for the determination came from four large population-based studies that found trans fat increases the risk of heart disease.
The US FDA expert panel concluded the evidence demonstrated a linear, or proportional, relationship with no threshold effect. In other words, there is no safe level of consumption of partially hydrogenated oils.
The FDA has set a compliance period of three years for industry to reformulate products without trans fats or request special exemption for specific products.
Voluntary reductions in Australia
Around half of the trans-fats in Australian diets comes from dairy and meat products.
Australia’s food standards regulator, Food Standards Australia New Zealand (FSANZ), has taken the view that public education and voluntary industry codes are the best approach to manage trans fats in the Australian context. Then, if needed, further regulations can be introduced.
Manufacturers have been encouraged to voluntarily reduce levels of trans fats in their products. FSANZ reports this is working; manufacturers have taken steps to reduce levels.
Food manufacturers are not required to disclose on packs when their products contain trans fats, or in what quantities. Current regulations require only that manufacturers label trans-fats if they make a nutritional claim about cholesterol or saturated, trans or other fatty acid.
So it’s difficult for Australian consumers to make informed decisions about their trans fat intake.
What can you do?
You can reduce the amount of trans fats in your diet by making some simple dietary adjustments that are also in line with the Australian dietary guidelines:
- Use oils and spreads made with canola, sunflower and olive oil
- Choose to steam, stir fry, poach, bake or grill your meat or meat products
- Reduce the amount of shallow- or deep-fried food you consume
- Select lean meat and trim visible fat
- Choose reduced-fat dairy products
- Limit your consumption of commercially baked products, takeaways and fast foods.
Lesley MacDonald-Wicks does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.
Authors: The Conversation Contributor