Most commercial soy milk sold in stores qualifies as ultra-processed under the NOVA food classification system, which is the framework most nutrition researchers use to categorize foods by their degree of processing. One analysis found that 90% of plant-based milk alternatives sold in the U.S. fall into NOVA Group 4, the ultra-processed category. That said, the label “ultra-processed” doesn’t automatically make soy milk unhealthy, and the classification depends heavily on what’s actually in the carton.
How NOVA Classifies Ultra-Processed Foods
The NOVA system sorts all foods into four groups. Group 1 covers unprocessed or minimally processed foods like fresh fruit, plain milk, and raw nuts. Group 2 includes culinary ingredients such as oils, butter, and sugar. Group 3 is processed foods, meaning simple combinations of Groups 1 and 2, like canned vegetables in brine or cheese. Group 4 is ultra-processed foods.
To land in Group 4, a product typically contains five or more ingredients, including substances not commonly used in home cooking. Think hydrolyzed proteins, modified starches, emulsifiers, stabilizers, colorants, and flavoring agents. The key distinction is that ultra-processed foods contain industrial additives designed to imitate or enhance the sensory qualities of less processed foods, or to mask undesirable tastes and textures in the final product.
Cow’s milk is classified as Group 1, a minimally processed food. Soy milk, by contrast, requires extraction, formulation with additives, and industrial processing steps that push most commercial versions into Group 4. This asymmetry is one of the most common criticisms of the NOVA system.
What’s Actually in Commercial Soy Milk
The base of soy milk is simple: soybeans and water. Soybeans are soaked, ground, boiled, and filtered to separate the liquid from the solid residue. At its core, that process isn’t far from what you’d do in a home kitchen. The ultra-processed classification comes from what happens next during commercial production.
Manufacturers typically add emulsifiers to keep the liquid from separating, stabilizers to improve texture, and oils for mouthfeel. Flavored varieties (chocolate, vanilla, cappuccino) contain additional flavorings and sweeteners. Unsweetened, unflavored versions skip the sugar and flavorings, but most still contain stabilizers or emulsifiers that qualify as industrial additives under NOVA’s definitions. The sugar in plain, unsweetened soy milk is naturally present in the soybean itself, not added.
Fortification is widespread. A survey of 52 commercial soy beverages found that 67% were supplemented with calcium, 71% with vitamin D, and 46% with vitamin A. Vitamin B12 appeared in about a quarter of products. These added vitamins and minerals are a significant nutritional advantage, especially for people using soy milk as a dairy replacement, but they also contribute to the longer ingredient list that triggers NOVA’s ultra-processed classification.
Why the Classification Is Controversial
Researchers have pointed out that NOVA’s grouping system creates some odd pairings. Soy milk sits in the same category as soft drinks, instant noodles, and packaged snack cakes. Meanwhile, cow’s milk, which undergoes pasteurization and homogenization at industrial scale, gets classified as minimally processed. The difference comes down to ingredient lists rather than the degree of mechanical processing.
This has led some food scientists to argue that NOVA fails to appreciate the nutritional value of plant-based dairy alternatives. Soy milk fortified with calcium and vitamins can be nutritionally comparable to cow’s milk, yet the classification treats them as fundamentally different types of food. The system was designed to flag industrial formulations that tend to be energy-dense and nutrient-poor, but soy milk doesn’t fit that pattern.
Health Effects of Soy Milk Itself
Replacing dairy milk with soy milk has been shown to reduce total cholesterol, LDL cholesterol (the type linked to heart disease), and C-reactive protein, a marker of inflammation. Soy milk consumption is also associated with a lower risk of breast cancer. These benefits come from soy’s protein and isoflavone content, which remain present regardless of the product’s NOVA classification.
Research comparing ultra-processed plant foods to unprocessed animal foods has found that the plant-based options often deliver better cardiometabolic outcomes. While whole, minimally processed plant foods are consistently the healthiest choice, products like soy milk can serve as practical stepping stones for people transitioning away from animal-based diets. The health picture for soy milk is considerably more favorable than for many other foods sharing its ultra-processed label.
Common Additives Worth Knowing About
Carrageenan, a thickener derived from red seaweed, appears in many soy milks. It’s approved by the FDA, and major food safety bodies have not found evidence of cancer risk or genetic damage from the food-grade form. However, animal studies have shown that degraded carrageenan can trigger intestinal inflammation, reduce gut bacterial diversity, and increase intestinal permeability. The European Food Safety Authority set a temporary acceptable daily intake of 75 mg per kilogram of body weight. If you have inflammatory bowel disease or gut sensitivity, you may want to look for carrageenan-free options, which are increasingly available.
Carboxymethylcellulose, another common thickener and stabilizer, has also raised some concern. A randomized controlled study found that 15 grams per day reduced gut bacterial diversity and short-chain fatty acid production in participants. European clinical nutrition guidelines list it as potentially increasing the risk of inflammatory bowel disease. The amounts in a serving of soy milk are far smaller than those used in studies, but the additive is worth being aware of if gut health is a priority for you.
How to Choose a Less Processed Option
Not all soy milks are created equal. The shortest ingredient lists typically belong to unsweetened, unflavored varieties. Some brands sell soy milk made with only soybeans, water, and added vitamins, skipping emulsifiers and stabilizers entirely. These products may separate in the carton and have a thinner texture, but they contain fewer of the industrial additives that drive the ultra-processed classification.
Making soy milk at home is straightforward. Soak dried soybeans overnight, blend them with hot water, strain the mixture through a fine cloth, and boil the liquid for 15 to 20 minutes. The result is a Group 1 minimally processed food by NOVA standards. The trade-off is a shorter shelf life (a few days refrigerated versus weeks or months for commercial versions) and no fortification with calcium or vitamins unless you add them yourself.
If you’re choosing between commercial soy milks, reading the ingredient list is more useful than relying on the ultra-processed label alone. A fortified soy milk with calcium, vitamin D, and no added sugar is a nutritionally dense product, even if it technically falls into the same NOVA category as a candy bar. The classification tells you something about how the food was made, but very little about whether it belongs in your diet.