Artificial and other non-nutritive sweeteners are now common in foods and drinks, and researchers are studying whether these calorie-free compounds affect blood sugar control and metabolic health. A recent review pooled evidence from randomized clinical trials and large observational studies to evaluate the health effects of these sweeteners.
Across 21 randomized clinical trials in adults, the review found that sweeteners, compared with non-caloric controls such as water or placebo, raised fasting insulin and HbA1c and showed a trend toward worsening insulin sensitivity. By using non-caloric comparators, the authors aimed to isolate the direct physiological effects of the sweeteners themselves rather than the calories they replace.
The review also discusses a trial that measured the gut microbiome and transferred microbes from humans to mice; certain low-calorie sweeteners altered microbial composition and function. Large observational studies generally linked sweetener use with higher cardiometabolic disease risk, but the researchers note limitations such as people at higher risk choosing these products and differences between sweeteners. They call for more carefully designed trials and advise caution in regular use.
Difficult words
- non-nutritive sweetener — sweet substance that provides little or no caloriesnon-nutritive sweeteners
- randomized clinical trial — study where people are randomly put in groupsrandomized clinical trials
- observational study — research that watches people without changing their behaviourobservational studies
- fasting insulin — level of insulin after a period without eating
- insulin sensitivity — how well the body responds to insulin signals
- gut microbiome — community of microbes living in the digestive tract
- placebo — inactive substance used to compare with real treatment
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Discussion questions
- Would you use foods or drinks with non-nutritive sweeteners regularly after reading this review? Why or why not?
- What concerns about observational studies do the researchers mention in the article?
- What kind of future trials would make the health effects of sweeteners clearer to you?
