Scientists warn swapping sugar for 'healthier' alternative still comes with an unexpected risk

Scientists have warned that swapping sugar for low or none calorie alternatives may not be as healthy as it seems, which could be seen as good or bad news depending on your viewpoint.

Since the first introduction of the artificial sweetener saccharin, a host of artificial and other low or none calorie sweeteners have become popular in the US food supply - with many people giving up sugar in a bid to keep healthy.

Popping a couple of sweeteners in your tea may make you feel a sense of satisfaction - but the result may not be so sweet.

A growing body of research suggests that these alternative products may not be as 'healthy' as first thought, and can actually have an adverse affect on some.

One report at Tufts University, published in Current Atherosclerosis Reports, pulls together the best available evidence on non-nutritive sweeteners and health.

Across 21 randomised clinical trials in adults, researchers observed that artificial and other low-calorie sweeteners, compared to non-caloric controls such as water or placebo, showed a trend toward worsening insulin sensitivity.

While many may assume sweeteners are a healthier alternative to sugar, it turns out this isn't quite the case (Getty Stock Image)

“What makes our analysis notable is that by focusing on non-caloric comparators, we better isolated the direct physiological effects of the sweeteners themselves, not the calories they replace,” said first author Meng Wang, a research assistant professor at the Friedman School of Nutrition Science and Policy.

“When pooling findings from individual trials, we see signals that these compounds may have metabolic harms.”

One explanation based on the current evidence, the researchers say, involves the gut microbiome. Non-nutritive sweeteners generally pass through the gut and come into direct contact with these microbes.

In one trial they reviewed, certain low-calorie sweeteners were shown to alter both the composition and the function of the gut microbiota.

Research studies also revealed that consuming non-nutritive sweeteners can be linked to a higher risk of developing cardiometabolic diseases.

More and more are trying to cut down on their sugar intake (Getty Stock Image)

These studies have limitations, however, as it has been noted that people already at risk for these conditions may be more likely to choose these products. Different sweeteners may also have different health effects, so grouping them may not give a full picture.

Taken together with the clinical trial findings, however, the researchers say that the overall body of evidence raises concern.

“The rapidly increasing use of these sweeteners has outpaced our understanding of their long-term health effects,” said study senior author Dariush Mozaffarian, a cardiologist and director of the Food is Medicine Institute.

“Until we know more, caution is needed. If you’re replacing large amounts of added sugar in your diet, such as in multiple servings of soda, these low-calorie sweeteners may be a better alternative.

Scientists say they can't assume that sweeteners are safe (Getty Stock Image)

"But we can’t simply assume they are safe and innocuous, and avoiding them whenever possible appears a prudent choice.”

Finally, the researchers highlight a gap in US labelling policy that hinders the research.

Current regulations require manufacturers to list non-nutritive sweeteners in the ingredient list, but the amount does not have to be included.

This makes it difficult for researchers to accurately assess non-nutritive sweetener intake and generate more concrete evidence about their health risk in large community or population studies.

The review highlights the need for additional carefully designed randomised controlled trials.