A study published in BMJ Nutrition Prevention & Health suggests that sparkling water may support weight loss by enhancing glucose uptake and metabolism in red blood cells. Conducted by physician researcher Dr. Akira Takahashi from the Tesseikai Neurosurgical Hospital in Japan, the findings indicate that although the effects on blood sugar are small, sparkling water could indirectly promote weight loss.
Dr. Takahashi explored how the carbon dioxide (CO₂) in sparkling water interacts with blood cells. Inside red blood cells, CO₂ is converted into bicarbonate (HCO₃), which makes the microenvironment of the cells more alkaline. "The alkalinization process initiated by bicarbonate conversion modifies the microenvironment of red blood cells, promoting glycolysis and enhancing glucose uptake," explained Dr. Takahashi, according to Libero Quotidiano.
Glycolysis, the process by which glucose is consumed to produce energy, is accelerated by the alkalinization of red blood cells. This means that the body may use sugar more efficiently, potentially aiding weight loss efforts. However, Dr. Takahashi cautioned that the impact of CO₂ in carbonated water is not a standalone solution for weight loss. "Given this minimal glucose reduction, the impact of CO₂ in sparkling water is not a miracle cure for weight loss. Healthy eating and regular exercise remain the basis for a good weight," he noted, according to Scientias.
To gauge the impact of this chemical reaction, Dr. Takahashi analyzed data from hemodialysis patients. During a typical four-hour hemodialysis session, around 48,000 milliliters of blood are processed, resulting in about 9.5 grams of glucose being used—the equivalent of a tablespoon of sugar.
Experts have expressed skepticism regarding the findings. "Even if we could demonstrate that the carbon dioxide in sparkling water increases glucose use by red blood cells, that would not necessarily lead to weight loss, however minimal," stated Professor Keith Frayn of the University of Oxford, according to The Sun. Similarly, dietitian Catherine Collins commented, "Without hard data, Takahashi's suggestion that the bicarbonate from carbon dioxide in sparkling water has a similar effect on glucose use as hemodialysis is purely speculative," as reported by Scientias.
The study authors emphasized that there are no quick fixes to slimming down and keeping off the weight. "A balanced diet and regular physical activity remain crucial components of sustainable weight management," they noted, according to The Mirror. Dr. Takahashi also highlighted potential side effects of consuming sparkling water. "Drinking carbonated water can have some effects on the digestive system, particularly for individuals with sensitive stomachs or pre-existing gastrointestinal conditions," he wrote.
"Moderation is key to avoid discomfort and still benefit from the possible advantages of sparkling water for your metabolism," Dr. Takahashi said.
"While there is a hypothetical link between carbonated water and glucose metabolism, this has yet to be tested in well-designed human intervention studies," said Professor Sumantra Ray, Executive Director of the NNEdPro Global Institute for Food, Nutrition and Health. "Any potential benefits must be weighed up against the potential harms of carbonated drinks which may contain sodium, glucose, or other additives," he added.
This article was written in collaboration with generative AI company Alchemiq