But are all fats bad? And is the law enough to keep your daily diet safe?

Nutrition is a tricky business – even if your goal is to just not die, let alone be as healthy as possible. Fats, the oily stuff found in parts of animals and some plants, aren’t much simpler. Not too long ago, traditional wisdom was to avoid fats altogether. But that turned out to be terrible advice. Sure, saturated fats (the kind you find lining the side of your steak ) raise your cholesterol and have a bad effect on your arteries, which can increase your risk of heart disease and worse. But there are also good fats, monounsaturated and polyunsaturated fats, the likes of the omega-3s, found in fish, nuts and olives. These are actually good for your heart and brain, and cutting them from your diet would be a bad idea for a list of reasons as long as your arm.

Ideally you want a balance between “bad” fats and “good” fats, although there’s still some work to be done on exactly what the ideal ratio is, never mind determining how you can achieve that ratio in your day-to-day diet. Nutrition is tricky, but chemistry can be simple. Some substances tend to explode, others never will. Some substances can kill you, others are safe except in the most outrageous of quantities. The point where chemistry and nutrition meet – highly processed foods – can sometimes be quite simple too. Which is why, since August 2011, there are now strict legal limits to the amount of man-made or artificial trans fats allowed in food in South Africa.

Synthetic trans fats were created to solve a problem that had haunted humankind since our ancient culinary ancestors figured out that fried stuff tastes good: vegetable oil is a pain to work with. Put it on a shelf and it tends to go off, put it in food and it leaves an unpleasant oily feel in your mouth. But treat that very same oil with hydrogen, a cheap and abundant element that can be applied in a cheap and uncomplicated way, and those problems go away. Partially hydrogenated vegetable oil, the end product of that process, will happily sit on the shelf for a long time, and it goes down real smooth. It also worked wonderfully well in baking, making for a better texture in biscuits, for instance. If you were running a restaurant or a food factory, this chemically hardened oil represented a modern miracle. As industrial-scale food processing grew in scale, so trans fats started to feature more and more in all kinds of things you are supposed to put in your mouth. Everybody was happy. Except that trans fats kill. In the right quantities (which isn’t very much at all), artificial trans fats are like little chemical machines designed to induce strokes and heart attacks. While normal bad fats will merely raise your level of bad cholesterol, the kind that clogs arteries, man-made trans fats simultaneously lower good cholesterol too.

The result is that, on a conservative estimate, trans fats have sent millions of
people to early graves by way of coronary heart disease. And that’s before you count the strong possibility that this monster substance also increases the risk of liver failure and diabetes, may contribute to the development of Alzheimer’s, increases the risk of prostrate cancer in men and breast cancer in women, and probably makes you fatter faster than other types of fat. How, exactly it manages to pack in so much malevolence is a matter of ongoing research, but artificial trans fats are bad in a way that other vilified foodstuffs can only aspire to. At least, we’re pretty sure they are. “As nutritionists, our big problem is translating what we’re learning into a language that is understandable, into steps that people can take in their daily lives,” says Marius Smuts, president of the Nutrition Society, who is currently working on the interaction between lipids and micronutrients, which could give rise to a new and complex set of requirements for the perfectly balanced diet. “When it comes to fat, we now have to talk about the quality of the fat as well as the amount, for example. But trans fat is easy. If you’re dealing with partially hydrogenated oil, you want none of it. It’s that easy.”

South Africa doesn’t exactly lead the pack when it comes to cracking down on palpable health risks. Recently, however, we haven’t been doing too badly – especially where those crackdowns are based on solid evidence, and where there’s relatively little economic impact. For example, going after major air polluters is difficult, because they happen to be major industrial companies that provide sorely needed jobs, and the link between what they pump into the atmosphere and people keeling over is often tenuous. On the other hand, banning Bisphenol A, or BPA, from baby bottles, is a no-brainer. BPA is now well understood as an endocrine disruptor, its ability to seep from plastic into liquid is proven, and messing with the hormone system in tiny humans is obviously a bad idea. Also, when you’re dealing with babies, minor scientific disputes around stuff like exposure levels don’t particularly matter.

Parents are a fierce breed, and there’d be little mercy for any manufacturer or government that wanted to nit-pick. With trans fats, the calculation was fairly easy. Evidence against them has been mounting since the early Eighties, and the scientific consensus has been well established. Other bans, in place for some time in parts of Europe and the US have also shown that there are little or no side-effects. In May 2010, a study published in the New England Journal of Medicine laid to rest the last concern: that manufacturers would just replace trans fats with lots of saturated fat, which would still be dangerous. Instead, with consumers ever more wary and conscious of labels, processed foods have become healthier overall. Large food-processing companies, seeing the writing on the wall, have been voluntarily reducing their use of both trans fats and natural bad fats over the last five years. Is that enough? Not necessarily.“Don’t think people will do the right thing unless you legislate it,” says nutritionist

Hettie Schönfeldt, a professor at the University of Pretoria who has been deeply involved in the trans fat debate. “Companies have been known to make changes in one part of the world, then keep dumping bad stuff in other parts of the world where it isn’t policed. We can’t take these things on faith.” Hence government regulations that limit the level of man-made trans fats in food to a maximum of 2% of the oil content. As of last year, importers can’t import anything above that level – and even if they did, retailers wouldn’t be allowed to sell it. In theory. It’s well beyond the ability of the Department of Health to test every consignment of oil that makes it onto our shelves, or go around to every restaurant doing spot-checks. But the world of food-processing is a cutthroat one, full of very large companies playing for very large stakes. Catching a competitor breaking the law – and putting consumers in real danger along the way – would be one hell of a coup. Given how relatively easy it is to replace artificial trans fats in most products, it’s just not worth the risk to be caught red-handed, and exposed in public. If you’re trying to avoid trans fats altogether, be prepared for some lifestyle changes. You’ll find trace amounts in some battered frozen foods, as well as in some chocolates. Most doughnuts are also packed full of them, plus you probably want to steer clear of any confectionary you didn’t make yourself, from scratch. If you’re unsure whether or not a product contains trans fat, make sure that you check the food packaging label. The biggest concern, though, is for the bottom end of the food market: the cheapest foods available to those with the least amount of money, putting them at bigger risk of ill health than middle-class South Africa. “The free market system means you’ll always have cheap fats available somewhere, and there will always be a demand for them,” says the Nutrition Society’s Smuts. “That’s very difficult to control and regulate, and there we’ll probably see trans fats pop up again and again.” Eventually, though, the expectation is that much reduced demand will see a virtual end to the production of partially hydrogenated fats.

Many hope that trans fats won’t be the last time the government intervenes in everyday food. “We’re hoping for strong regulation when it comes to salt content in food, and we’re supporting the Department of Health in that,” says Erika Ketterer, head of research and programmes for the Heart and Stroke Foundation. “We also want to see rules on marketing to children, and a tuck shop policy that will ensure schools have healthy foods on sale.” Researchers have also identified a list of potentially nasty food chemicals that rank between “Maybe” and “Very Likely” to cause cancer. Some are pure toxins that slip into the food chain, such as a group of bioaccumulative nasties commonly referred to as dioxins. Some are added deliberately, such as the nitrates used to keep processed meat safe and prettily red, and which may also cause Parkinson’s disease and cancer. And some are accidental creations inherent in the way food is prepared, such as acrylamide, a compound that will likely make headlines in coming years. Acrylamide, long used to treat wastewater and process ores, was only discovered in food in 2002, when Swedish researchers stumbled across it by accident. It’s been looking more and more like a problem ever since.

“We know this stuff is in potato chips, and we’ve done some measurements on that,” says Dr Carl de Vos Albrecht, head of research for the Cancer Association of South Africa. “The thing is that acrylamide can form all by itself when you heat up certain types of starch enough and different types of potatoes will give you different concentrations. We have no upper limit set for it, so what happens if a company that makes chips switches potatoes? There’s no indication on the packet, so one day you could be getting very little, the next day 10 times as much.” But while studies on rodents make for worrying reading, the link between acrylamide and cancer in humans is still inconclusive. So don’t expect rapid action. In the meanwhile, though, we can at least cut down on the trans fats. And maybe reduce our exposure to acrylamide. But by the best estimates it will be 20 or more years until we know for sure if there is something even more harmful lurking in your lunch box.