Sunday, April 24, 2011
The sour truth about sugar
By Jennifer O’Connell
My American friend, Kate, underwent a painful break-up last summer. It was worse than any split with a boyfriend, she insists. In fact, she can’t imagine that her marriage falling apart could possibly have been any more traumatic.
Kate ‘broke up’ with the mother of her son’s best friend.
“I thought we had so much in common. They boys got on a like a house on fire. We had the same approach to parenting – I thought. Then we went on holidays together,” she explained, staring dolefully into her skinny decaff soy latte.
“We had lunch on the first day, and I just knew.”
What happened? I gasped. “She ordered the boys a Coke.”
When I’d finished laughing (it took a while), Kate – who’s always ahead of the curve in these matters – ordered me to go home and watch a YouTube video of a lecture by a paediatric specialist in endocrinology to students at the University of California entitled, Sugar: The Bitter Truth.
I did go home and watch the video – all 90 minutes of it.
In the lecture, the paediatrician, Robert Lustig, explains how the world is seeing an epidemic of obese six month olds; how the average American is consuming between 185 and 300 calories more per day than they use up; how drinking one can of soft drinks per day adds up to over a stone in weight in the course of a year; how, as far as your liver is concerned, sugar is just as toxic as ethanol.
His central point is that the focus on fat and simply overeating as the main cause of the obesity epidemic is wrong-headed and misleading.
Instead, he says, sugar is to blame – and not just for obesity, but also for the increase in heart disease, hypertension and some of the most common kinds of cancer. “The fat’s going down, the sugar’s going up. And we’re all getting sick,” he says.
He also believes that not all sugars are created equal. Refined sugar – sucrose - and the fructose found in juices are just as “dangerous”, just as “poisonous”, as the much maligned high-fructose corn syrup found in soft drinks and almost every processed food - and much more dangerous than the glucose found in carbohydrates.
Whole fruit contains fructose, but since it also has fibre, which Lustig says acts as an “antidote”, it’s okay. Fruit juice is not.
I was shocked. And then my 3-year-old asked for a glass of apple juice, and I promptly forgot about it.
But I remembered Kate’s break-up story last weekend when I came upon a lengthy article in the New York Times entitled ‘Is Sugar Toxic?’
The article sets out to stand up or debunk the claims made by Lustig. It points out that, although he’s a specialist in endocrinology, he hasn’t actually carried out any of the studies he cites himself.
It points out that he uses the world ‘evil’ five times in his lecture; and the word ‘poison’ 13 times. It admits that part of the appeal of his message is that he’s a compelling public speaker, and that he has a habit of taking suggestive evidence and presenting it as incontrovertible.
But it also finds that almost everything he says in that 90 minute lecture is scientifically valid.
Lustig’s theory is that the obesity epidemic is not simply down to us consuming more calories than we expend – the ‘empty calories’ theory. Instead, it’s how our body handles sugar in refined or liquid form – sucrose or fructose – that makes these types of it so dangerous.
Glucose – which is consumed in carbohydrates like pasta, rice and bread – delivers a hit to every cell in the body, where it is broken down and converted to energy. If you consume 120 calories of glucose, for instance, only 24 will end up in your liver.
But fructose can only be metabolised by the liver. If it hits the liver at sufficient speed, in sufficient quantity, the liver starts converting it to fat, a process which causes you to get fat, and – because some of the fat never makes it out of the liver – also eventually leads to insulin resistance.
Insulin resistance can cause diabetes, hypertension, heart disease – and may even be a hidden factor in many common cancers.
If it’s true, Lustig’s theory turns just about everything we thought we know about nutrition on its head.
We knew sugar was bad for your teeth, and that if you consumed too much of it and didn’t exercise enough, it could make you fat.
It’s true sugar is bad for your teeth but it’s also harmful to your liver, your heart and may be a carcinogen. And you should be far more worried about your liver than your teeth – because as far as your liver is concerned, fructose is just as toxic as ethanol, it’s “alcohol without the buzz”.
Not all sugars are created equal, either – sugar from carbohydrates (glucose) is easily metabolised and unlikely to end up as fat in healthy adults. But 30 per cent of sugar from fructose ends up being converted to fat. As Lustig says: “A high sugar diet IS a high fat diet.”
You might remember that the next time you consider ordering a Coke for your child – or someone else’s.
But you should think about it, too, the next time you smugly spear a juice carton with a straw for your child; let them have a fructose-packed ‘healthy’ yoghurt drink; douse their vegetables in sugar-packed ketchup to encourage them to eat; offer sweetened yoghurts as a healthy option, or give them a flavoured milk drink, because they won’t drink milk.
Lustig ends his lecture by explaining the four changes he insists the obese children attending his clinic make.
They drink nothing except milk or water. They eat their carbohydrates with fibre – (because “when God made the poison, he packaged it with the antidote”.) They always wait twenty minutes before they go back for seconds. And every minute they spend in front of a screen must be ‘bought’ with a minute spent exercising.
To Kate, I want to apologise for calling you nuts. Neurotic, maybe. But not so nuts after all.
This column first appeared in The Sunday Business Post on April 24, 2011
Image courtesy of wikimediacommons.org