Fact v fiction on fructose
Fructose has copped a bad rap in recent years, so what do you need to know about this particular type of sugar – and is it actually that bad?
If you’ve read about fructose, it may have been painted as a nutritional bogeyman.
But has fructose has been unfairly singled out?
University of Canberra adjunct professor Dr Kerry Mills says while fructose is certainly not a health food, it is not solely responsible for these health issues.
“Sugar is sugar is sugar – more or less,” Dr Mills says.
“Nobody should say fructose is healthy, but it pretty much has the same effect on body weight as other sugars, like glucose. On a calorie-by-calorie basis, fructose is no worse than other sugars.”
In fact, several high-quality studies have shown fructose, sucrose and glucose all act similarly in the body.
What is high-fructose corn syrup?
Much of fructose’s bad name stems from high-fructose corn syrup, a sweetener mainly used in the US in lollies, biscuits, cakes, soft drinks and breakfast cereals.
Dietitians Australia spokesman Dr Alan Barclay says high-fructose corn syrup is not widely used in Australia and it is not pure fructose – it is about 55 per cent fructose and 45 per cent glucose.
“At the turn of the millennium, scientists in the US looked at the increasing consumption of high-fructose corn syrup and rising rates of obesity and connected the two,” Dr Barclay says.
“They also did studies on animals involving very high doses of fructose and found it led to increased fat in the body and weight gain.
“But the amount of fructose given to those animals was much higher than people can tolerate and, unlike rodents, humans convert most fructose to glucose in the small intestine, not fat in the liver.
“Also, high-fructose corn syrup and other added sugar consumption has decreased in America but obesity rates continue to rise, so fructose alone isn’t to blame.”
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How much sugar is too much?
Other common sugars include glucose, lactose and sucrose – a combination of glucose and fructose.
Fructose is mostly found in fruits and in some vegetables and honey.
On average, Australian women have 50g of free sugar and men have about 70g of free sugar a day – and about half of that is fructose, according to Dr Barclay.
Free sugars include all sugars added to foods and drinks, plus the sugars naturally present in foods, such as honey and fruit juices.
The World Health Organisation recommends adults and children reduce their daily intake of free sugars to less than 10 per cent of their total energy intake.
It says reducing free sugars to below 5 per cent, or about six teaspoons a day, provides additional health benefits.
“Carbohydrates of all kinds, including sugars, are energy dense so we should avoid having sugars for no reason. If you do have sugar, it’s better to have it with other nutrients like a piece of fruit that has vitamins, minerals and fibre, too,” Dr Mills says.
What if you are fructose intolerant?
Some people, particularly those with irritable bowel syndrome, can’t tolerate large amounts of fructose and follow a low-fructose diet to avoid symptoms such as diarrhoea, bloating, stomach pain, nausea and wind.
High-fructose foods include:
- Apple juice
- Palm or coconut sugar
- Dried fruits
- Sugar snap peas
- Canned fruit in natural fruit juice
- Tomato paste
Lower fructose foods include:
- White potato
Written by Sarah Marinos.