Section 1.1: Nanoparticles in Popular Beverages

A study from 2017 identified fluorescent nanoparticles in two of the world’s most consumed drinks: Coca-Cola and Pepsi. These foodborne nanoparticles (NPs) can arise from production processes or be intentionally added for various reasons, such as enhancing flavor, aiding nutrient absorption, prolonging shelf life, and creating more vibrant colors. The absence of global regulations requiring product labeling complicates efforts for consumers to learn about the presence of nanoparticles in commercial foods. Research has also found these NPs in other items like bread, biscuits, cornflakes, and caramelized sugar. Additionally, fluorescent NPs were discovered in products such as Nescafe, Tsingtao beer, fermented drinks, and sports beverages.

While nanoparticles in food are often viewed negatively, their toxicity is not well understood, leaving us uncertain about their actual effects. Scientific inquiries into these foodborne NPs could shed light on their risks and benefits, empowering consumers with crucial knowledge.

Section 1.2: Key Findings from Recent Research

Fluorescent nanoparticles in Coca-Cola and Pepsi were observed under UV light when released from their cans. These NPs were isolated and analyzed for cytotoxicity (the potential to harm cells), acute toxicity (short-term adverse effects), and their distribution in experimental animals. Simulated human digestion was performed using artificial saliva and gastric juices to mimic the digestive process.

The nanoparticles identified in Coca-Cola and Pepsi measured 5 nm, smaller than those found in bread and jaggery.

Cytotoxicity assessments were conducted on Chinese hamster ovary cells, revealing that the NPs from Coca-Cola exhibited lower cytotoxicity compared to those from Pepsi. Notably, no significant cytotoxic effects were observed at nanoparticle concentrations below 20 mg/mL.

Acute toxicity was tested on three groups of mice, each comprising ten individuals (five males and five females), who were given the NPs from both beverages. The major organs showed no signs of acute toxicity at the dosages administered. Biochemical analyses revealed some statistically significant differences between the test groups and controls; however, these were not biologically meaningful.

In vivo biodistribution studies involved 27 female mice, divided into nine groups. Eight groups received a single dose of NPs orally, while one group served as a control. The NPs from both drinks accumulated in several areas of the digestive tract, such as the small intestine and colorectum, suggesting that these particles may be cleared from the body through feces. Notably, accumulation was also recorded in vital organs like the liver, brain, and heart within 2-6 hours after administration. Increased fluorescence in the brain six hours post-consumption indicated that the NPs could cross the blood-brain barrier. However, by 24 hours, the fluorescence levels in major organs decreased to baseline, suggesting that the NPs were excreted. Notably, the NPs from Pepsi reached maximum fluorescence in the small intestine after just 15 minutes.