Anyone trying to follow a healthy, active lifestyle will be aware that sugar is not exactly a health food. We take a look at the recent controversy around the supposed “toxicity” of sugar and suggest ways of sticking to a sensible level of sugar consumption.
Sugar has been in the news a lot recently. Whilst the fact that overconsumption of sugar is probably not very good for us can hardly be described as new or startling, the vehemence with which the dangers of sugar have been described – to the point of calls for governmental regulation of sugar levels in our foods – has certainly grabbed the public's attention. Dr Robert Lustig, a paediatric endicrinologist form the University of California, has caused considerable controversy with his claim that sugar is a “chronic toxin” responsible for many, if not most lifestyle-related illnesses in the West, including heart disease, obesity, type 2 diabetes, hypertension and many of the more common forms of cancer. Whether the “sugar” in question is sucrose or fructose, it can do damage to our bodies that is rather more far-reaching than the traditional concerns around tooth decay and empty calories. In an article published in the journal Nature in February this year, he suggested that sugar should be regulated, much like tobacco and alcohol, as it causes comparable damage to health.
How does sugar damage our health?
What happens when we consume sugar? The liver and pancreas work to secrete insulin in response to the foods we consume in order to keep blood sugar levels steady. In a normally functioning metabolism, a delicate balance is achieved between burning off blood sugar for energy and using insulin to store excess sugar away as fat. However, when there is chronic over-consumption of sugar, a condition known as metabolic syndrome or insulin resistance can develop. It's as if the cells in your body are no longer registering the insulin secreted in response to the food you consume, so the pancreas and liver go into overdrive, secreting more and more insulin. There is no longer a balance between insulin and blood sugar levels. A vicious cycle is easily established, as fructose, in particular, also suppresses leptin production – leptin being the hormone that lets us know when we are full – so it is easy to consume more and more sugar without ever feeling like we've had enough. In its extreme form, metabolic syndrome evolves into diabetes. But even without full-blown metabolic syndrome, obesity is a serious risk of excessive sugar consumption and chronically elevated insulin levels are harmful in themselves – they are thought to play a role in heart disease, for example.
All of this is complicated by the fact that sugar is an addictive substance. It produces a pleasure response in the brain when consumed (activating dopamine pathways that are also involved in our responses to sex, gambling, and opiates, for example); chronic consumption leads to habituation and the need to consume more; and withdrawal symptoms can be highly unpleasant. The addictive nature of sugar probably has its origins in our evolutionary history: Tens of thousands of years ago, sugar in any form was a rare and precious source of energy, to be consumed with abandon when available in order to lay down stores of fat for times of scarcity. For our caveman ancestors, it made sense to be addicted to sugar. In our present day lives, it's an enormous hazard.
Some practical advice for a healthier diet
Taken together, these strands of evidence make a compelling case against the excessive consumption of sugar. Note the use of the word “excessive.” The British Dietetic Association recommends that we do not exceed 50 grams of “added” sugars – that's jams, honey, fruit juices, soft drinks and sugars in processed foods – a day, constituting 10% of the calories in an average 2000-calorie diet. That sounds sensible enough, but it can be very hard to keep track of our sugar consumption since sugar is omnipresent in our society. Here are some ideas for helping you to stay within sensible limits:
- Avoid or reduce the obvious culprits – sweets, fizzy drinks, cakes, biscuits and so on.
- Read labels on processed foods. It is startling to realise the many hiding places of sugar, from smoked salmon to ketchup. Investigate sugar-free alternatives.
- Remember that sugar is sugar. Glucose, dextrose, invert syrup, corn syrup, treacle, hydrolysed starch, maltose, raw sugar, cane sugar, brown sugar – it's all sugar. Avoid or limit.
- Beware of so-called “energy” or “sports” foods. Unless you're a high-performance athlete (and even then it's debatable), there is no reason to reach for a cereal bar or a sports drink.
- Some foods seem obviously wholesome. Think of honey or fruit juice. Then ask yourself how much you should be consuming, and whether it wouldn't be better to consume in a different form (e.g. a piece of fruit and some water probably make more sense than drinking the equivalent of 25 oranges).
Above all, change your thinking. If you can think of sugar as a potentially addictive and destructive substance to be handled with care and used sparingly, the rest should follow pretty easily.
by Kath Webb
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