The bitter truth about sugar

Recently an American doctor called Robert Lustig has been calling for laws that restrict sugar as if it were alcohol or tobacco. Like many people, I suspect, my initial reaction upon hearing this was: give me a break. Lustig, who thinks sugar is a dangerous poison, has considered several strategies. For instance, we could double the price of fizzy drinks, so children can’t afford them. We could get sweet shops to close in the afternoons, when children are going home from school. We could restrict the advertising of foods with added sugar. We could even set an age limit for fizzy drinks, possibly 17, so younger kids can’t buy cans of Coke. Dear me. Whatever next? It’s easy to understand the reasons for controlling tobacco and alcohol — these things are toxic and costly for everyone. If you smoke or get drunk, I end up paying your hospital bills; if you don’t smoke or drink, I pay less tax. So of course alcohol and tobacco should be restricted. Tobacco causes an array of diseases; alcohol can destroy your liver, and it also makes people shout and fight and vomit in the street. Both are addictive. But sugar? The stuff you sprinkle on your cereal? That makes cakes and chocolate taste nice? My first thought was: yes, I know it’s bad for you. Yes, it rots your teeth — if you don’t clean them afterwards. Yes, if you eat too much, you get fat. Yes, it can tinker with your metabolism, so when you eat sugar, you crave more. And I know first-hand about the phenomenon of the sugar high — I have a six-year-old son. But surely it should be up to us how much sugar we eat. We don’t want the sugar police, do we? Even as I was thinking this, I realised something slightly alarming: part of me doesn’t want to hear really, seriously bad news about sugar. I have enough to worry about. I’d like to remain in mild denial, thank you. Sugar is part of life. It’s pleasant. It’s everywhere. Poison, schmoison. Who is this Robert Lustig, anyway? He’s a professor of clinical paediatrics at the University of California, San Francisco, and an expert on childhood obesity. Scientifically, Lustig is an endocrinologist. His area of expertise is human metabolism — how our bodies break down food and turn it into energy. Some of his lectures are on YouTube. Recently, he’s gone viral. This middle-aged, grey-haired, slightly stocky guy, who wears a suit and tie and talks about the metabolism of fructose, has had more than two million hits. In the lectures, Lustig is mesmerising. He tells us more or less the same story he’s outlined in a recent issue of the journal Nature. “The UN Secretary General,” he says, “declared that non-communicable disease — that is, diabetes, heart disease, obesity, cancer and Alzheimer’s disease — is a bigger threat to the entire world, developed and developing, than is infectious disease.” He tells us that these diseases kill 35 million people every year. He says that there are 30 per cent more obese people in the world than undernourished people. In 2011, there were 366 million diabetics in the world — more than double the number in 1980, and 5 per cent of the population. In the US, by 2030 this figure might be as high as 33 per cent. At this point, he had my attention. Remember when almost nobody had diabetes? That wasn’t long ago. These days, many of us know somebody with the disease. And what about high blood pressure, heart disease, fatty liver, and chronic fatigue? What about depression, food cravings, addictive overeating? Think about all the people we walk past every day who are really, really fat. Not just plump but off-the-scale fat. Within living memory, these people were rare. Now you see them every day. And it’s not necessarily their fault. “Nobody chooses to be obese,” says Lustig. “Nobody. Especially not children. This is a global pandemic. D’you think, all of a sudden, everybody in the world became gluttons and sloths at the same time? Get with the programme!” What’s going on? “It ain’t the fat,” says Lustig, when I speak to him on the phone. The obesity epidemic, and the sudden flourishing of all these non-communicable diseases, is not a result of people eating too much fat. We know this because, in the Seventies, the entire Western world went low-fat. The medical establishment believed it had discovered a link between dietary fat and heart attacks. As we now know, the situation was fairly complicated — some fats, notably Omega-3 oils, are actually good for your heart. Still, in the Seventies, the food industry cut back on fat. We had low-fat yogurt, low-fat ready meals, low-fat sauces, low-fat everything. The problem, Lustig tells us, “is that, when you take the fat out, it tastes like cardboard. They had to do something.” What did they do? “They added carbohydrate. Which carbohydrate? High-fructose corn syrup and sucrose.” So about 35 years ago, the developed world made a radical change in its diet. We stripped away fat, and added sugar. For instance, since 1990, consumption of sugar in Britain has increased by 31 per cent – now we eat 1.25lbs per person a week. There are seven spoonfuls of sugar in a can of cola. Lots of people know that. But do you know that more than 60 per cent of a Slimfast drink is made up of sugar? Did you know that, in Britain, children get around 17 per cent of their calories from sugar? One interesting fact is that, year on year, we’re buying fewer actual bags of sugar — “visible sugar”. The big increases are in “invisible sugar” — the sugar the food industry sneaks into things. Looking around my local supermarket, let me tell you what I found. There is glucose-fructose syrup in one organic yogurt; organic sugar and organic invert sugar syrup in another. There is fructose in Müller Light. There is sugar in Hovis bread, sugar in healthy-looking Burgen bread, dextrose in Warburton’s wholemeal bread. There is fructose syrup in my Forest Feast dried berries. There is sugar in the steak pie. There is sugar in the smoked salmon. There is sugar in the seafood sticks. There’s a cheese I like, Wensleydale with apricots, which is delicious – thanks to the added fructose. There are sausages with sugar. Why is there sugar in all these things? Partly, it’s because we, the consumers, want it. We want everything to be sweeter these days; we wouldn’t like to go back to the good old days, when smoked salmon tasted fishy and salty and dried cranberries tasted tart. The food writer, Felicity Lawrence, recently conducted a study of fruit. She found it was getting sweeter. That’s how farmers are breeding it. We want our apples, strawberries and grapes to taste sweeter — partly because everything else does. When you add sugar to one thing, you have to add it to other things, too, so they won’t be left behind. Have you got a headache? Take an ibuprofen. It’s probably sugar-coated, like a Smartie. There’s undoubtedly a correlation between our increased sugar intake, over the past 30 years, and this explosion in obesity, diabetes and other metabolic problems. But are things so simple? Robert Lustig is very busy when I speak to him. He’s rushing around a great deal, giving talks. This, it seems, is his moment. I ask him about the correlation between sugar intake and obesity. “Correlation is not causation,” he says forcefully. “If we didn’t have causation I wouldn’t be speaking in public. And I’m happy to stack the science up against anybody who wants to countermand it.” One of the most important things he says concerns what happens in your liver when you eat fructose. There’s a complicated chain of events, but the upshot is something called “leptin resistance”. Leptin is a hormone produced to tell us when we’re full; it’s the “satiety hormone”. When we eat too much fructose, leptin is sometimes switched off. We don’t know when we’re full. That’s why so many people are off-the-scale-fat these days. They don’t have a proper satiety signal. The sugar they eat causes them to produce too much insulin, which gives them blood-sugar crashes, which makes them crave more sugar, and on and on. Meanwhile, they develop insulin resistance. Next stop: diabetes. Somewhere down the line: huge health care costs. Sugar’s everywhere. It’s addictive, it’s toxic, and, in the end, we all have to pay for it, if not with our health, then at least in our taxes. That’s why Lustig thinks it should be controlled like alcohol and tobacco. For a substance to be controlled, it must have four characteristics. It must have the potential to be abused. It must be toxic. It must be widespread. And it must cause problems for people other than those who abuse it. Sugar, of course, ticks all these boxes. Incidentally, there’s a reason why fructose switches off our satiety signal. Or at least a hypothesis. Lustig says it might be because there was a time of year, harvest time, when ancestral humans had an abundance of fruit, followed by a time of year, winter, when they had almost nothing. So we evolved to overeat at harvest time. Fructose makes us want to eat more; it tells us not to be satisfied. That was good, then, when food was scarce. It wasn’t so good later, when it was less scarce. It’s a disaster now, when it’s everywhere. That’s Lustig’s argument. There is, of course, a really big problem. That’s the food industry. “The food industry,” Lustig tells me, “has no impetus to change. They’re making money hand over fist.” We’ve all heard of Big Tobacco. Well, there’s something even bigger to worry about — Big Sugar. The obesity expert Philip James puts it this way: “The sugar industry has learnt the tricks of the tobacco industry. Confuse the public. Produce experts who disagree. Try to dilute the message.” Lustig has been accused of “irresponsible” fear-mongering by the food industry. He has some allies but none of the big hitters, while broadly agreeing with him that sugar is a problem (although disagreement exists about which type of sugar is the worst) goes as far as him in terms of regulation. There’s Kelly Brownell, an obesity expert and professor of psychology at Yale. “He thinks a penny-an-ounce soda tax will reduce consumption. I don’t,” says Lustig. There’s Marion Nestle, professor of nutrition, food studies and public health at New York University, and author of Food Politics: “she isn’t necessarily for regulation”. Gary Taubes, the low-carb guru, “doesn’t believe that leptin is crucial to the argument. I do.” Michael Pollan, the author of In Defence of Food, “doesn’t even pretend to understand the science”, and “doesn’t specifically come out against sugar per se”. And is there anyone in the UK even remotely on the same page as Lustig? “Not that I know of,” he says. What if Lustig is right? What if sugar is the culprit? What can we do? We can start the long, laborious process of coming out of denial. We’re doing it with alcohol. We’ve done it with tobacco, which was a huge struggle. But it’s working. Most people used to smoke. Now most people don’t. We made it expensive, harder to buy, and harder to advertise. We kept it away from children. We made it taboo. Can we do this with sugar? I’d love to think we could. But sugar is a tougher opponent than tobacco. Tobacco was in cigarettes, cigars and pipes. Sugar is everywhere. It’s in the pies. It’s in the beans and the toast. It’s in the sausages and the gravy. To radically cut our intake would be to radically shake up the economy. So don’t expect miracles. For an example of what Lustig is up against, look no further than the Starr Report, the investigation into Bill Clinton by the prosecutor Kenneth Starr. One section describes the moment President Clinton was interrupted by a phone call during an intimate moment with Monica Lewinsky. The person on the line was reportedly Alphonso Fanjul, a Florida sugar baron, complaining about a proposed sugar tax. Clinton took the call. The tax was dropped.