'I really want to quit': Your café oat latte may contain more additives than you think

"I had been drinking an oat latte at a café every day. I chose it because it has fewer calories than milk and carries a healthy, plant-based image — I had no idea it contained additives. My stomach is sensitive, so I really want to cut them out." — A woman in her 40s who works in an office

As concerns grow over excessive additive consumption, the range of products that rely on food additives continues to expand. Oat drinks, which have become a popular milk alternative at coffee shops, are no exception.

The oat drinks used at coffee shops differ from standard retail versions. They are "barista edition" products developed specifically for café use. Regular oat drinks tend to clump or separate when mixed with hot, acidic coffee, and they struggle to produce the dense, stable foam that milk delivers. Other plant-based drinks, such as soy milk, can have the same problem. To address this, manufacturers turn to food additives — acidity regulators, emulsifiers, thickeners and stabilizers.

Oat-based drinks are naturally low in fat and protein compared with milk, giving them a thin consistency. Blending in plant oils such as canola oil can replicate the mouthfeel of milk, and emulsifiers help the oil and water mix smoothly. Thickeners are added to produce the creamy texture associated with dairy.

Acidity regulators reduce the clumping and separation that can occur when hot, acidic coffee meets oat drink. Stabilizers keep hard-to-mix ingredients from separating over time.

Kang Jae-heon, a professor of family medicine at Kangbuk Samsung Hospital and a former chairman of the Korean Academy of Family Medicine, said that consuming too much phosphate — one type of acidity regulator — can interfere with calcium absorption. "It could also hinder children's growth and development, or raise the risk of osteoporosis," he said.

A review of ingredient labels on four major barista oat drink products sold in South Korea found that all contained food additives. The overall variety of barista oat drinks on the market was also limited.

That does not mean regular oat drinks contain fewer additives than barista versions — ingredient profiles vary considerably by product. A survey of seven regular oat drinks sold domestically found that the number of ingredients classified as food additives under Korea's food additive code ranged from as few as two to as many as 12. Ingredients used for nutritional fortification, such as vitamins, were excluded from the count.

Drinking oat milk does not, of course, automatically harm one's health. The concern is that consumers easily end up ingesting multiple food additives simultaneously across their daily diet. The recent "zero sugar" trend has also multiplied the number of food and beverage products containing artificial sweeteners, including low-sugar drinks sold at cafés. Consuming such additives frequently over a long period is where the health calculus changes.

A notable piece of research published in June speaks directly to this issue — a warning about "combined exposure" to multiple additives.

Romanian researchers, writing in the international journal Frontiers in Public Health, said that in real-world diets people do not consume a single additive in isolation but rather ingest multiple additives mixed together over long periods. "Existing regulations on additives assess each ingredient individually, so they fail to adequately reflect the risks of this kind of combined exposure," they wrote.

The researchers also warned that additives that individually fall below safety thresholds can still produce negative effects through "cumulative exposure" and "interactions between ingredients" in the gut microbiome and immune environment when consumed together with other additives.

Kang also said that while food additives enhance the taste and shelf life of products, consuming them excessively over a long period can place a burden on health.