Sugar has been described as toxic, evil and addictive. The truth, however, is far more subtle – it’s the dose that matters


If you’re interest in health media – or media in general – you’ve probably come across a popular internet meme that seems to perfectly convey the supposed horrifying effects of sugar on our brains.

It shows two brain scans side by side with a similar pattern of brightly coloured blotches on each. The word ‘sugar’ appears under the first scan and ‘cocaine’ under the second. The blotches are meant to indicate activity in the reward centres of the brain, and the relatively straightforward conclusion – an association that almost anyone can make – is that sugar has the same addictive effect on our brain as the illegal Schedule 1 drug, cocaine.

Sugar has been described as ‘evil’, ‘toxic’, ‘poison’ and a ‘silent killer’, and its harmful effects on health has even been compared to smoking. You’ve probably heard that sugar ‘feeds’ cancer and that it causes diabetes, but there’s no hard scientific evidence to prove this. In fact, respected health information sources such as the Mayo Clinic and Health24 categorise these claims as ‘myths’. While the South African Journal of Clinical Nutrition states there is ‘emerging evidence that increased sugar consumption also relates to micronutrient dilution, hypertension and coronary heart disease’, sugar’s vilification as the root of all lifestyle-related ills is not entirely warranted. Surely where there’s smoke, there’s fire? Well, sure. However, the equation is infinitely much more complicated than sugar plus human equals disease.

Let’s pause for a brief lesson in nutrition. Sugars are a type of carbohydrate, says Vanessa Clarke, a registered dietician in Durban. ‘Carbohydrates are responsible for providing the majority of the energy our bodies require, and they exist in three forms: simple or complex carbohydrates and fibre.

‘Simple carbohydrate is the term for sugar, and sugars exists in two forms, namely simple and free sugars. Simple sugars occur naturally in fruit and milk, whereas free sugars are those that are generally added to baked goods and to your tea and coffee. Complex carbohydrates include more starchy foods and grains,’ she says.

Free (or added) sugar has the potential to erode our health. It is not known how consumption directly leads to disease, which is why no one can claim that it does. What is known is that this carbohydrate can contribute to weight gain, which is a risk factor for many non-communicable diseases. Even then, sugar is just one in an intricate web of variables that influence each other and our health, including genetics, exercise, diet, social factors as well as the environment.

‘One of the biggest misconceptions is that sugar is poison,’ says Cape Town-based registered dietician Kim Hofmann. ‘Adding a teaspoon of sugar to your tea or breakfast cereal is not going to damage your health. Using sugar in large quantities will. There is a big difference.’

So it’s a question of context. The form as well as quantity of sugar consumed is critical to the discussion, not the substance itself. Even the most innocuous comestibles could pose a threat to health if consumed in excess.

Free sugar makes sure we’re hungry again soon after. But it’s not the same as drug addiction. it’s hard to imagine someone stealing a car stereo to get a Mars bar

It’s true though that the Western world eats too much sugar for its good health. Reports state that the average Briton eats 238 teaspoons of added sugar, while the average American consumes up to 329 teaspoons of added sugar a week.

The South African National Health and Nutrition Examination Survey found in 2013 that one-in-five South Africans consume excess sugar, while the World Health Organisation is considering halving its recommendation of the maximum daily intake of added sugar from 10% of a daily kilojoule intake to 5% – about six teaspoons. If excessive sugar consumption does affect us adversely, the more appropriate question becomes: is it addictive?

Cape Town-based registered dietician Kelly Lynch believes that ‘refined foods [containing mainly sugar or refined grains that are man-made] may have addictive qualities for three reasons. Firstly, they taste good so people enjoy eating them; secondly, they cause large disturbances – spikes and drops – in our blood sugar levels and this can create sugar cravings; finally, foods high in sugar do not generally keep us full as they are normally very low in fibre and protein, so we get hungrier faster – and then want more.’

Hofmann agrees, saying that ‘when you look at sugar in its different forms – that is, a teaspoon of sugar in coffee versus a chocolate – it’s the chocolate that I have seen to be addictive, not so much a bit of sugar added to whole foods. This begs the question: is it the sugar that is addictive or the sweet treats, which generally contain lots of saturated fat as well as the sugar?’

Food high in fat and sugar certainly entice us to eat more because they taste delicious, and the free sugar makes sure we’re hungry again soon after. But it’s not the same as drug addiction. As one website puts it, it’s hard to imagine someone stealing a car stereo to get a Mars bar.

The sugar/cocaine brain scan meme mentioned earlier is dramatic – and it’s meant to be – but the link between the two scans has been described as ‘spurious’ and ‘inappropriate’ in scientific circles.

The average Briton eats 238 teaspoons of added sugar, while the average American consumes up to 329 teaspoons of added sugar a week

So, what should we do to avoid falling into the sweet, sticky embrace of a sugar ‘addiction’?

‘It is best to avoid or limit the consumption of free or added sugars and replace them with healthier alternatives,’ says Clarke. ‘Free sugars offer very little nutritional benefit.’

Cutting out added sugar is easier said than done, though, as it is included in many processed foods. Not just the kind you’d expect, such as fizzy drinks, fast food, sweets and baked goods, but savoury products and even ‘health’ foods such as cereals and yoghurt. It’s therefore always good to check the label.

‘I give my clients a tip when looking at a food label: compare the “of which sugars” column to the “dietary fibre” column. Preferably choose foods that are higher in dietary fibre than sugar,’ says Lynch.

She also advocates a whole-food diet. ‘Try to make 80% of your diet whole food dominant – a whole food is normally a fresh food [lean meat, chicken, fish, vegetables, fruit, nuts, seeds etc].

‘Or if the food is packaged, check that the food label only has one ingredient on the ingredients list. So if you buy whole oats or brown rice, ensure it only says oats or rice on the ingredients list,’ she says.

The bottom line is if you’re healthy and eating a balanced diet with plenty of fruit and vegetables, wholegrains and low-fat protein, with low levels of added sugar, the odd teaspoon of sugar in your tea, slice of cake or bar of chocolate isn’t going to have much of an impact on your health.


By Rachel Mcgregor
Image: Gareth van Nelson/HSMimages