Boot camp Melbourne

IT SURPRISES many people when they find out that trans fats are not a new thing – in fact we’ve been consuming them for centuries! That’s because trans fats turn up naturally in foods such as beef, lamb and goat, as well as any products that are made from them, including milk, butter, cream or cheese. But don’t panic – these trans fats, which are created by bacteria that live in the rumen (or forestomach) of cattle, sheep, goats and deer, occur in small amounts only and there’s no evidence the natural forms are dangerous. It’s the industrially produced trans fats that are the problem, and they are a far more recent development.

Manufacturers turned to hydrogenated fats – the source of this newer kind of trans fat – during the 1970s and 1980s, when animal fats like butter, tallow and lard were under suspicion due to their saturated fat content.

They needed to find a way to make oils stay solid at room temperature, which helps with spreadability, texture, crispness and shelf life, and hydrogenation was the answer.

However, in the process of producing a fat that gives biscuits and potato chips a good crisp bite, and pies and pastries a nice flaky texture, hydrogenation also changes a fat’s molecular structure, which results in a portion becoming a trans fat (see box below).

These hardened fats have many advantages for manufacturers – they can be made from cheap plant oils and the products they’re used to make have a longer shelf life without needing refrigeration. But while hydrogenated fats were
seen as the ideal alternative to the saturated fats they were made to replace, the manufactured fat now seems in many ways worse.

Animal fats such as butter and lard contain 3 per cent of their total fat in the trans form, while hydrogenated shortening used in baking generally contains 30 per cent – 10 times more.
This is why dietitians are most worried about the trans fats found in deep-fried and processed foods that are made with a solid commercial fat or shortening (see box, right).

Manufacturers are required to list total fat and saturated fat in the nutrition information panel on food labels, however it’s not compulsory for them to list the amount of trans fats. You’ll only see a figure for trans fats on products with a claim such as “No cholesterol” or “Low in saturated fat”. Margarines and oils usually list it because almost all margarines in Australia and New Zealand are now free of trans fats.

You can’t see or taste trans fats, just like you can’t see the 70 per cent of monounsaturated fat that makes up the fat in olive oil. They’re part of the make-up of the fat and will occur in smaller or larger proportions depending on the food.

Sometimes you’ll read about “hydrogenated” fat and sometimes it’s “partially hydrogenated” fat, where the hardening process is not complete. If you see this phrase on a product’s list of ingredients, it’s a sure sign the product contains trans fats but you won’t know how much.

WHAT TRANS FATS DO TO YOU

Like saturated fats, trans fats can raise both your total blood cholesterol level and your LDL (the “bad” component of cholesterol), say the experts at the Heart Foundation. But they can also lower the “good” HDL cholesterol which in turn increases the risk of heart disease, the leading cause of death in Australia and New Zealand.

The Heart Foundation people want us to limit our intake of both saturated and trans fats, and now gives recommendations in the form of “saturated plus trans” fats. Because we consume considerably more saturated fat than trans fats, the experts say, a lower intake of saturated fat will have a greater overall impact on heart health.

Compare that to the US where, in a 2005 report, the National Academy of Sciences (NAS ) was much stricter and concluded there is no “safe level of trans fat consumption”. This is because even a small increase in trans fats intake increases the risk of coronary heart disease.

There’s also some evidence that trans fats increase the likelihood of type 2 diabetes, liver problems and even infertility, but at this point there isn’t enough convincing evidence to say
that conclusively.

ALARM BELLS

Nutritionists have long been aware of trans fats but for some time considered them harmless and not really relevant. In fact, no-one worried about them until the publication of a paper by Dutch researchers in 1990. These scientists were the first to notice that high intakes of trans fats raised the bad LDL yet lowered the good HDL cholesterol. It was sound research and was later repeated and verified in other studies.

Following this, Australia’s two major margarine manufacturers, Flora and Meadow Lea, made all their spreads virtually trans-free, dropping them from around 12 per cent down to less than one.

And to put Australia’s trans fat situation into perspective, the intake of trans fats here is relatively low compared to the US and other Western countries, largely because we have not had to rely on hydrogenated soy bean oil in the way the US has (until recently, about half the soy bean oil in the US was hydrogenated); we have used palm oil for frying and processing instead (however, while palm oil has no trans fats, it is high in saturates so it’s not kind to your heart either). So it pays to be wary when reading material from overseas – often the hype about trans fats doesn’t apply here.

Since January 2006, the US Food and Drug Administration (FDA) has made labelling for trans fats compulsory on all foods. This has spurred on American companies to change cooking oils and find non-trans fats for cookies, fries, snacks, confectionery and other processed foods.

Before that, in 2003, Denmark became the first country in the world to ban the sale of foods with over 2% industrially produced trans fat.

In Australia, the early move in the 1990s to cut the trans fats in our margarines dropped the intake of trans fats here significantly, says CSIRO researcher Associate Professor Manny Noakes from the Human Nutrition division in Adelaide. She points out that trans fats often deflect attention away from saturates, which are consumed in far greater quantities and are more of a problem for heart disease.

WHAT REALLY COUNTS

Essentially, you shouldn’t choose foods based on their trans fat total alone. Instead, try to choose products with the lowest total “saturated plus trans” fat content possible.

For example, butter has about 3 per cent trans fats, whereas a shortening for use in baking made from hydrogenated canola oil has 30 per cent trans fats. If you made a choice based on trans fats alone, you’d opt for the butter. However, it contains about 54 per cent saturated fat, while the shortening has just 5 per cent. You’d have made a better choice if you’d based it on the combined fat total (shortening at 35 per cent and butter at 57 per cent).

To keep up do date on the issue of trans fats, keep reading HFG, and look out for information on reputable Australian
websites such as the Heart Foundation (www.heartfoundation.com.au), Nutrition Australia (www.nutritionaustralia.org) or the Dietitians Association of Australia (www.daa.asn.au). 30 www.healthyfoodguide.com.au

CATHERINE SAXELBY is an accredited practising dietitian and founder of www.foodwatch.com.au.

WHAT ARE THEY?

Trans fats (also called trans fatty acids or TFAs) are a type of fat that is classified chemically as unsaturated, but its molecules are “rearranged” so it behaves as though it is a saturated fat. Let’s take oleic acid and its chemical “twin” elaidic acid, for example. The only difference between them is their shape – oleic acid has a kink, while elaidic is fairly straight. This straight form makes elaidic acid more solid and gives it a higher melting point.
Elaidic acid is the main trans fat found in hydrogenated vegetable oils, whereas oleic acid is the major monounsaturated fatty acid in food (technically in the “cis” form, which is bent).



FOODS TO WATCH

• Deep-fried fast food such as French fries, chips, wedges and nuggets – partially hydrogenated oils are generally used for deep-frying unless you are told otherwise
• Fried salty snack foods, such as potato crisps and corn chips
• Baked goods like meat pies, sausage rolls, apple pies and croissants
• Doughnuts
• Manufactured biscuits, cookies, muffins and cakes
• Instant noodles
• Packet cake mixes
• Gravy powder
• Microwave popcorn
• Non-dairy coffee whitener
• Frozen foods including fish fingers, crumbed chicken and spring rolls
• Solid cooking margarines


TRANS FATS IN AUSTRALIA

We have few figures on the level of trans fats in our foods. In 2005, Choice magazine analysed 55 foods and found that 18 of them had trans fats at more than 2 per cent of their total fat – the cut-off many experts consider to be safe.
This list was fairly predictable, with burgers, nuggets, fries, frozen pastry, sausage rolls, hazelnut spread and chocolate-biscuit snacks.
But we’re not too badly off, thanks largely to the Heart Foundation, which has been pushing manufacturers to get rid of industrial trans fats. Its Tick program has been particularly successful.
This was verified in a recent survey by Food Standards Australia and New Zealand (FSANZ) which reported that “Australians obtain only 0.6 per cent of their daily kilojoules from trans fats and New Zealanders only 0.7 per cent. This is well below the World Health Organization recommendation to consume no more than 1 per cent of your daily kilojoules from trans fats and below many other countries.”
 

HOW TO AVOID THEM

• Avoid any fast food that is deep-fried unless you know a low-trans oil has been used. (It’s a good idea for your health to avoid deep-fried takeaway food anyway.)
• Avoid commercially made biscuits, pies, slices, muffins and quiches. (You can bake these at home using regular margarine.)
• Avoid bought pastry, such as shortcrust or puff.
• Shop for a soft spread (margarine) rather than a hard one (cooking margarine) – most spreads are now made with less than 1 per cent trans fat. You can see this on the label.
• Use oil instead of margarine or butter whenever you can, such as when baking or making dressings and sauces. Look for cake recipes (such as banana cake) that work well using oil instead of solid fats.

Healthy Food Guide
www.healthyfoodguide.com.au