New Study Investigates the Effects of Sweetened Beverages on Salivary Insulin and Aspartame Levels
A recent study published in Food Research International aimed to determine whether the consumption of sweetened beverages affects the levels of salivary insulin and aspartame. The study also explored the impact on salivary alpha-amylase and total protein.
The global consumption of foods and beverages containing sweeteners is high, as many individuals naturally prefer a sweet taste. This has led to the widespread use of non-sugar sweeteners as a replacement for sugar due to their reduced caloric density. However, there is a lack of evidence regarding the long-term benefits of these sweeteners, especially in relation to their effects on metabolism and potential adverse effects.
The study focused on three common synthetic sweeteners: aspartame, cyclamate, and acesulfame potassium. Aspartame, which contains aspartate and phenylalanine, is the most widely used sweetener globally. Sodium cyclamate, despite being banned in some countries, is approved as a food additive in others. Acesulfame potassium is a synthetic compound that is not metabolized.
The digestion of sugars begins in the oral cavity with the presence of salivary alpha-amylase. The sweet taste stimulates taste buds in the oral cavity, triggering processes such as increased salivary secretion and insulin secretion. Insulin release occurs in response to stimulation from sweet-tasting receptors, leading to lower blood glucose levels and increased appetite. Salivary alpha-amylase is directly related to carbohydrate absorption and glycemic index.
To investigate the effects of sweetened beverages on these factors, a single-blinded randomized trial was conducted. Fifteen healthy young adults, all with normoglycemia and healthy oral conditions, participated in the study. They were asked to refrain from consuming sweeteners in their diets for one week before and during the trial.
During the trial, the participants were asked to drink five different test drinks in separate sessions. The drinks included diet soft drinks, regular soft drinks, mineral water with sweeteners, the same products with low sucrose content, and water. Saliva samples were collected at different time points after consumption: before ingestion, 15 minutes after ingestion, 30 minutes after ingestion, 60 minutes after ingestion, and 120 minutes after ingestion.
The study found that aspartame was detected in the saliva of individuals who consumed diet soft drinks and water with sweeteners. The concentration of aspartame remained steady over time, indicating its prolonged presence in the digestive tract. Interestingly, a correlation between aspartame concentration and insulin levels was observed only for diet soft drink intake and not for sweetened water. This suggests that sweetened water is metabolized more quickly than diet soft drinks. Additionally, both regular and diet soft drinks led to increased insulin levels, with a greater rise observed for regular soft drinks between certain time points. No changes in salivary alpha-amylase activity were observed after consuming sweetened beverages.
In conclusion, the study demonstrated that diet soft drinks led to higher levels of salivary aspartame compared to water with sweeteners. Both regular and diet soft drinks resulted in higher salivary insulin levels compared to control and low sucrose content drinks. These findings provide further insight into the effects of sweetened beverages on metabolism and support the need for additional research in this area.
Reference:
Finassi, CM, Calixto, LA, Segura, W., et al. (2023) Effect of sweetened beverages intake on salivary aspartame, insulin and alpha-amylase levels: A single-blind study. Food Research International 173. doi:10.1016/j.foodres.2023.113406