Daijiworld Media Network – New Delhi
New Delhi, Feb 26: Continuous glucose monitors (CGMs) have revolutionized diabetes management, but a new study suggests they may do more harm than good for healthy adults. Researchers warn that these devices could provide misleading blood sugar readings, potentially leading to unnecessary dietary restrictions.
Originally designed for diabetics, CGMs track blood glucose fluctuations by measuring the glycemic index (GI) of foods. However, their growing popularity among health-conscious individuals has raised concerns about accuracy in non-diabetic users. A peer-reviewed study published in The American Journal of Clinical Nutrition reveals that CGMs may overestimate blood sugar levels in healthy adults, prompting unnecessary changes in diet.
“CGMs are incredibly useful for diabetics, even if they aren’t perfectly accurate, as they provide a crucial point of reference. But for those with normal glucose control, they can be misleading,” said Professor Javier Gonzalez from the University of Bath’s Department for Health.
“Healthy individuals relying on CGMs may end up avoiding perfectly good foods due to inaccurate readings. Traditional blood sugar testing remains the gold standard for accurate assessment.”
To test CGM reliability, researchers compared blood sugar readings in healthy volunteers (non-diabetic, within a healthy BMI range) using two methods: CGM readings and finger-prick tests (gold standard). Participants consumed fruit-based products, ranging from whole fruit to smoothies, and the results were surprising. CGMs consistently reported higher blood sugar levels than finger-prick tests. Smoothies’ GI was overestimated by 30%—CGMs reported a medium GI of 69, while the traditional test showed a low GI of 53. Whole fruits were misclassified as medium- or high-GI by CGMs, while finger-prick tests confirmed they were low-GI. The study debunked the myth that blending fruits into smoothies raises their GI—whether eaten whole or blended, fruits like apples, bananas, mangoes, and oranges remained low-GI.
Professor Gonzalez explains that CGMs measure glucose levels in the fluid surrounding cells, rather than directly in the blood. This can cause discrepancies due to factors like time delays in glucose absorption, blood flow variations, and differences in glucose distribution across the body.
While CGMs remain invaluable for diabetics, the study cautions against using them as a dietary guide for healthy individuals. Their potential for inaccurate readings could lead to unwarranted food restrictions. Until improvements are made, traditional finger-prick tests remain the most reliable method for assessing blood sugar responses.