The bitter truth about high-sugar diets and artificial sweetener consumption

Excessive consumption has been linked with no less than 45 chronic illnesses, including heart disease and cancer

Pic: iStock

As a registered dietitian running nutrition clinics across Ireland for the past 12 years, Orla Walsh is all too familiar with the problems stemming from a high-sugar diet.

“Sugar intake is too high in Ireland,” she says. “Half of us will die from heart disease and the more sugar we eat, the more likely that is. We do need to reduce our intake of free sugars, as found in the likes of cakes, biscuits, some breakfast cereals, fruit juice and sweets.”

This has been confirmed by numerous studies over the last year. The latest damning report in the British Medical Journal identified associations between sugar consumption and no less than 45 chronic illnesses, from type 2 diabetes to depression, asthma, heart disease and some cancers.

Since the 1980s, food manufacturers have increasingly turned to sweeteners such as sucralose, cyclamate, acesulfame-K, aspartame, and stevia to produce sugar-free yet flavoursome products. The high potency of some of these sweeteners — aspartame is 180 to 200 times sweeter than sugar — has allowed companies to make so-called zero-calorie or diet products relatively cheaply.

In recent years, sweeteners have become dogged by suggestions that they perpetuate many of the same health concerns they were supposed to negate. In 2022, an analysis of over a decade’s worth of dietary records from more than 100,000 adults in France linked higher consumption of aspartame and acesulfame-K to various cancers. Earlier this year, data collected from more than 450,000 adults across Europe linked greater consumption of sugary or artificially sweetened beverages to an elevated risk of thyroid cancer.

Walsh suspects this may be linked to the negative impact of sweeteners on the gut microbiome, driving inflammation, which is behind many disease processes.

“When we eat sweet foods with sweeteners in them, we’re eating processed food and our gut microbiome isn’t grateful,” she says. “It would prefer we eat wholefoods, which have gone through less processing, and would prefer we focus on eating a variety of plants.”

Orla Walsh, registered dietitian

Sweeteners may lead to overeating

Other research has suggested that consuming sweetener-rich foods could make people hungrier and drive them to overeat because such intensely sweet flavours disrupt the brain’s reward centre.

Clare Reynolds, an assistant professor in the School of Public Health at TCD, says we urgently need to understand more about the underlying biology behind why sweeteners appear to be associated with adverse health outcomes and whether they tend to be part of an overall dietary pattern which is driving risk.

“The results that are starting to emerge are concerning,” she says. “There definitely seems to be a link between artificial sweetener consumption and non-communicable diseases such as cardiovascular disease and diabetes.”

Such concerns are now driving food scientists to look for healthier alternatives. Instead of synthetic chemicals, they are returning to sources of sweetness within nature.

One such potential sugar alternative is monk fruit extract, a powder used in Chinese traditional medicine for centuries. The extract contains a substance called mogroside V that is calorie-free and more than 200 times sweeter than sugar, making it an appealing solution.

Another idea being explored is so-called sweet proteins such as miraculin and brazzein, which are found in the berries of various West African shrubs.

Miraculin, first discovered by Japanese scientists in the 1960s, has historically received the most attention due to its natural taste-tripping properties. The protein binds to and temporarily changes the shape of taste receptors on the tongue, making sour foods such as lemons and limes seem remarkably sweet.

However, in recent years, food experts have become more interested in another sweet protein known as monellin, which Delia Picone of the University of Naples believes has far more commercial potential than miraculin due to its practicality.

“It has a very small size so it can be produced in a cheap and scalable way,” she says.

While naturally occurring sweeteners have previously struggled to gain commercial traction due to the sheer costs of growing the fruits in which they occur and then extracting them, new technologies are making this far more feasible than before. In particular, the rise of gene editing has enabled scientists to design modified bacteria that can produce these proteins in bulk through fermentation.

Picone has created a modified version of monellin, which remains stable during cooking or in the presence of acids. She believes that this could enable the protein to be used as a natural flavouring in sauces or soft drinks.

Tweaking sugar crystal

As well as turning to nature, another possibility is utilising clever chemistry to tweak the sugar crystal in ways that enable manufacturers to produce sweet treats and desserts that taste just as appealing but have much less sugar.

Israeli company Incredo has figured out an ingenious way to combine sugar crystals with miniature silica grains. This addition makes sugar dissolve faster on the tongue, enabling the same sweet taste to be achieved with far less.

While these innovations are promising, Picone cautions we still need studies that confirm that these alternatives are healthier and less addictive than the current range of artificial sweeteners and conventional sugar. However, food scientists unanimously agree that it is vital for the industry to explore better solutions for the sake of our health.

“There’s a high incidence of health problems in people who consume more sugar, so it’s become more and more important to find what we can actually do to suppress this intake,” says Nenad Naumovski, a researcher at the University of Canberra in Australia.

“Whether that’s developing newer, safer sweeteners that are less calorific or finding things that can be combined with sugar in smaller quantities to reduce that impact.”