The Function and History of Brominated Vegetable Oil (BVO)
Brominated vegetable oil, often abbreviated as BVO, is a food additive used to ensure that citrus-flavored oils remain suspended within a water-based beverage. Without an emulsifier like BVO, the citrus flavorings, which are oil-based and less dense than water, would separate from the rest of the liquid and float to the top, creating an unappealing presentation. To create BVO, a vegetable oil (such as soybean or palm oil) is chemically modified by bonding it with atoms of the element bromine. This process increases the oil's density, allowing it to remain evenly mixed throughout the drink.
BVO had been used in food products in the United States since the 1920s. For a period, it was considered by the FDA to be “generally recognized as safe” (GRAS). By the late 1960s, however, animal studies began to raise concerns about the safety of BVO, leading the FDA to remove it from the GRAS list in 1970. Despite this, the FDA allowed its continued use on an interim basis, permitting a maximum concentration of 15 parts per million (ppm) in fruit-flavored beverages while further studies were conducted. Mountain Dew, a popular citrus soda, historically contained BVO to stabilize its iconic flavor profile.
Mounting Health Concerns and The Regulatory Ban
For decades, the safety of BVO remained a subject of regulatory review and public concern. The central issue revolves around the body's ability to accumulate bromine from the consumption of BVO.
Potential Health Risks
- Thyroid Interference: Studies in rodents, including one conducted by the FDA in 2022, indicated that exposure to BVO can cause negative effects on the thyroid gland. This is because bromine can interfere with the body's uptake and utilization of iodine, a crucial element for proper thyroid function. The thyroid gland regulates metabolism, heart rate, and other vital bodily functions, so its disruption can have broad health impacts.
- Neurological Effects: Excessive bromine accumulation in the body can lead to a condition called bromism, which is associated with neurological symptoms. Case reports have described individuals who consumed large quantities of BVO-containing soda experiencing symptoms like headaches, fatigue, memory loss, and impaired coordination.
- Residue Accumulation: Research has shown that brominated fat molecules from BVO can accumulate in body fat, as well as in the fat of major organs like the heart, liver, and brain. While the direct human health consequences of this build-up were not fully established at the time of the ban, the possibility of long-term organ toxicity was a significant concern.
Based on these accumulating concerns and new research, the FDA issued a proposed rule to revoke the authorization for BVO in food in November 2023. This was made final in July 2024, with a compliance date of August 2, 2025, giving manufacturers time to clear existing inventory. Many countries, including those in the European Union, India, and Japan, banned BVO decades ago.
The Shift to Safer Alternatives
In anticipation of and reaction to mounting pressure and regulatory action, many beverage manufacturers, including PepsiCo (the producer of Mountain Dew), began phasing BVO out of their products years before the final ban. The reformulation required replacing BVO with other, more widely accepted emulsifiers. Some common alternatives used to stabilize flavorings in beverages today include:
- Glycerol Ester of Wood Rosin (GEWR): A food additive derived from pine trees that provides similar emulsifying properties to BVO.
- Sucrose Acetate Isobutyrate (SAIB): A synthetic compound also used as a stabilizer and clouding agent.
- Gum Arabic: A natural gum harvested from acacia trees that functions as an effective emulsifier and stabilizer.
- Modified Cellulose: A plant-derived polymer that helps stabilize emulsions and can provide a smoother texture.
Comparison of Emulsifiers
| Feature | Brominated Vegetable Oil (BVO) | Glycerol Ester of Wood Rosin (GEWR) & Sucrose Acetate Isobutyrate (SAIB) | Gum Arabic & Modified Cellulose |
|---|---|---|---|
| Source | Vegetable oil modified with bromine. | Derived from pine trees or chemically synthesized. | Natural, plant-based gums. |
| Function | Keeps citrus oils suspended in beverages. | Keeps citrus oils suspended, providing stability. | Stabilizes emulsions, often offering a smooth mouthfeel. |
| Health Concerns | Linked to bromine accumulation, potential thyroid and neurological issues. | Generally considered safe for food use by regulatory bodies. | Considered safe for consumption. |
| Regulatory Status | Banned by the FDA in 2024. | Permitted for food use by the FDA. | Permitted for food use by the FDA. |
| Usage in Beverages | Historically used in many citrus sodas, including Mountain Dew, now discontinued. | Common BVO alternatives in citrus-flavored beverages. | Frequently used as natural emulsifiers in a variety of foods and drinks. |
Conclusion
While brominated vegetable oil in Mountain Dew was once a standard additive to prevent the separation of citrus flavors, it has been definitively removed from the formulation. The transition away from BVO is a direct result of ongoing scientific research and regulatory action by the FDA, which ultimately determined that the additive was no longer safe for human consumption, primarily due to concerns about bromine accumulation and potential adverse effects on the thyroid and nervous system. Today's consumers can enjoy reformulated versions of Mountain Dew and other citrus sodas that use safer, approved alternatives like GEWR or SAIB. This shift reflects a broader trend toward greater scrutiny of food additives and a move by manufacturers to prioritize ingredients with established long-term safety records.
For more information on food additives, you can visit the FDA's official website to find details on their regulatory actions and policies.
