Which Sugar Is Worse: Glucose Or Fructose?

A recent article published in the Medical Journal of Australia found that Australian and European soft drinks contained higher concentrations of glucose, and less fructose, than soft drinks in the United States. The total glucose concentration of Australian soft drinks was on average 22% higher than in US formulations.

We know too much sugar is bad for us, but do different sugars have different health effects? Let's take a look at the science.

We compared the composition of sugars in four popular, globally marketed brands – Coca-Cola, Fanta, Sprite and Pepsi – using samples from Australia, Europe and the US. While the total sugar concentration did not differ significantly between brands or geographical location, there were differences between countries in the concentrations of particular sugars, even when drinks were marketed under the same trade name.

Whether these differences have distinct effects on long-term health is currently unclear. Certainly, over-consumption of either glucose or fructose will contribute to weight gain, which is associated with a host of health conditions such as type 2 diabetes and heart disease. And because the body metabolises glucose and fructose in different ways, their effects may differ.

Sucrose, glucose and fructose

Soft drinks, as they are referred to in Australia, or “sodas” in the US and “fizzy drinks” in the UK, are non-alcoholic, carbonated, sugar-sweetened beverages. Australia ranks seventh out of the top ten countries for soft drink sales per capita.

Sugars are the chief ingredient in soft drinks and include glucose, fructose and sucrose. The source of sugars in popular soft drinks varies between global regions. This is because sugars are sourced from different crops in different areas of the world.

Soft drinks in Australia are primarily sweetened with sucrose from sugar cane. Sucrose, often referred to as “table sugar”, is composed of one glucose molecule and one fructose molecule joined by chemical bonds. This means equal amounts of glucose and fructose are released into the bloodstream when sucrose is digested.

Overseas, soft drinks are sweetened with sucrose-rich sugar beet (Europe) or high-fructose corn syrup (US). High-fructose corn syrup is also made up of glucose and fructose, but contains a higher fructose-to-glucose ratio than sucrose.

Do they have different health impacts?

Fructose over-consumption is known to contribute to fatty liver disease. Fatty liver disease affects about one in ten people in the West. Non-alcoholic fatty liver disease is the leading cause of liver disease.

Some researchers have suggested too much fructose in the diet can harm the liver in a similar fashion to alcohol. However, this concern is related to added fructose in the diet, not natural sources. Natural sources of fructose, such as fruit, honey and some vegetables, are not generally over-consumed and provide other important nutrients, such as dietary fibre and vitamins. So, fruit does not generally pose a risk for fatty liver disease.

High glucose consumption rapidly elevates blood glucose and insulin. This may affect brain function, including mood and fatigue. Because high blood glucose is linked to diabetes, consumption of high-glucose drinks may also raise the risk of diabetes and cardiovascular (heart) disease.

All soft drinks are considered energy-dense, nutrient-poor and bad for health. However, one of the inherent challenges in the field has been an inability to determine the actual dose of glucose or fructose in these drinks.

Studies that follow people over time, and link soft drink consumption to adverse health effects, are complicated by not knowing whether individuals in these studies are simply eating too many energy-rich foods, and whether soft drink consumption coincides with other poor health behaviours. So, further research is required to determine whether soft drinks containing different concentrations of fructose and glucose are associated with differing health risks.

Soft drink policies

There is still much to learn about the differences in composition of sugars and patterns of soft drink intake between countries. A small number of countries, including Mexico and France, have already implemented taxation on soft drinks. It remains to be determined whether these actions reduce the incidence of obesity, diabetes and heart diseases.

Australian policymakers are yet to take action to reduce soft drink consumption. A range of intervention strategies have been considered, including banning sugary soft drinks in schools and hospitals, taxation, and regulating beverage marketing.

The ConversationThe New South Wales Health Department has just announced sugary drinks will be phased out of vending machines, cafes and catering services in the state’s health facilities by December. This is a great move. Importantly, we must continue to increase public awareness of the adverse health effects of sugary soft drinks.

Bronwyn Kingwell, Head, Metabolic and Vascular Physiology NHMRC, Senior Principal Research Fellow, Baker Heart and Diabetes Institute; Pia Varsamis, PhD Student, Metabolic and Vascular Physiology, Baker Heart and Diabetes Institute, and Robyn Larsen, Postdoctural Research Fellow in Nutritional Biochemistry, Baker Heart and Diabetes Institute

This article was originally published on The Conversation.


Comments

    This seems to be discussion on which poison is the least "bad" for us.

    Which sugar we are consuming doesn't matter due to the massive quantities of sucrose/fructose/glucose in "soft" drinks. Consuming 8-14 teaspoons of any sugar in one drink will not help your health.

    In the US High fructose corn syrup is pretty much in everything - even foods you'd not think needed a dose of sugar. Combined with the super-sized servings everyone eats over there it is little wonder that yanks are so huge

    It's all sugar, it's all bad and the reason it's in everything is that it is essentially addictive. So yes, now I'm going to rant on about the big corporations and their money grubbing ways at the expense of the health of the population. Sugar is damned near as hard to kick as a habit, as Meth and the corporations are counting on you not being able to kick it. Farmers over there are paid extra to grow crops for corn syrup by the big corporations and the Government, so they would lose money if they decided to grow anything else. Is it any wonder the health of the planet is in decline, we need to wake up as a species and be more subjective about what we shove down our collective throats.

    Well I made the decision a few years ago to never (as much as possible) buy processed food and never to cook out of a jar. When making my curries or other sauces I have found that I have to add a small amount of sugar to most to balance the flavours but nowhere as much as there is in a jar of sauce.

    Introduce your kids to flavours and how to taste them early and they won't miss all that sugar.

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