Bad fat a slippery slope to the grave

Bad fats used in most takeaway shops' deep-fryers are killing New Zealanders from heart attacks and strokes.

Diet experts have long tried to steer consumers away from their love of deep-fried fish, chips and the like.

More recently they have tried to improve takeaway chefs' cooking techniques to cut fat content. Now they are focusing on the different types of fats or oils, some of which are good and some bad.

Hot chips are a crucial battleground: because we eat so many of them - 7 million servings a week; because they contain so much fat - on average 11.5 per cent of each chip; and since takeaways are a growing part of our diet.

Forty per cent of deaths each year are from cardiovascular disease, mainly heart disease and strokes, conditions fuelled by bad fats.

Obesity is becoming more common.

The Heart Foundation says lives could be saved if food manufacturers switched from unhealthy fats like tallow and partially solidified canola to specialised sunflower oils or one called Liquid Gold, a mix of the sunflower oils and cottonseed oil. Another healthy one is rice bran oil.

"The Ministry of Health talks about 11,000 deaths per year due to nutrition-related factors," foundation nutritionist Judith Morley-John said yesterday.

"That's not all directly related to frying, but it shows a lot of deaths are related to nutrition,"

Research she participated in, published today, shows that none of 148 independent and chain outlets surveyed used fats that met the foundation's recommendations. Even when it added a caveat allowing slightly less healthy oils because the new, top-quality ones were hard to obtain, only one passed.

It also shows that 82 per cent used beef tallow, 7 per cent palm oil and 11 per cent either cottonseed, soybean or canola oil.

Whether it's healthy is in the different levels of the various fatty acids in each type of fat.

"Saturated fat increases the risk of heart disease and increases the amount of bad cholesterol in the blood.

"Trans-fat is at least as bad as saturated fat," said Mrs Morley-John.

Good oils for deep frying are those high in mono-unsaturated fatty acids.

Tallow and palm oil are considered stable - they have a longer frying life than vegetable oils that are liquid at room temperature, which tend to introduce unpleasant tastes to the chips sooner.

Manufacturers tried to get around this by adding hydrogen atoms to the oils, which makes them partially solid at room temperature, but which also creates trans-fatty acids.

Trans-fats have become the focus of health campaigners in the United States, where takeaway chains and biscuit makers are under pressure to reduce levels.

Since the Heart Foundation survey, the McDonald's fast food chain has switched in New Zealand to what Mrs Morley-John said was a healthier type of frying oil.

A mix of the specialised sunflower oil with liquid canola, it has negligible trans-fats and produces chips with lower saturated fat.

But because it needs to be replaced more often than the tallow it superseded, and costs more to start with, it adds more than $1 million a year to the chain's expenses.

"We're going through everything," said McDonald's spokesman Liam Jeory, "to seek to reduce fat, salt and sugar content [under a commitment to] the Food Industry Accord."