Over the past decade, plant-based beverages have surged in popularity, with oat, almond, soy, and rice drinks emerging as well-known alternatives to cow’s milk. As millions of liters of these drinks find their way into consumers’ shopping carts, the driving factors often include their perceived environmental benefits, as these plant-based options typically have a lower climate footprint than cow’s milk. However, a recent study conducted by the University of Copenhagen, in collaboration with the University of Brescia, Italy, highlights the complex reality that these plant-based beverages are not necessarily healthier alternatives.
Published in the journal Food Research International, the study explores the ways in which chemical reactions during the processing of plant-based drinks affect their nutritional content, comparing them to traditional cow’s milk. The findings suggest that while plant-based beverages are often considered to be a more sustainable and sometimes healthier choice, they may not be the nutritional substitutes many consumers believe them to be.
The nutritional differences between plant-based drinks and cow’s milk largely stem from the manufacturing process. Cow’s milk, being a finished product as it comes from the cow, undergoes relatively gentle heat treatments, such as low pasteurization, to preserve its nutritional integrity. On the other hand, plant-based drinks, such as those made from oats, rice, or almonds, require more extensive processing to convert the raw ingredients into drinkable beverages. Many of these drinks undergo Ultra High Temperature (UHT) treatment, a process widely used for extending the shelf life of dairy products globally. This treatment involves heating the beverages to temperatures as high as 135°C (275°F), which alters the structure and nutritional quality of the drink.
In Denmark, where the study took place, milk is generally sold in refrigerated sections with a low-pasteurization treatment, keeping more of its original nutrients intact. In contrast, the UHT process, necessary for long shelf life and mass production, comes with trade-offs in terms of nutrition. According to Professor Marianne Nissen Lund, who led the study, UHT treatment induces a chemical reaction known as the Maillard reaction. This reaction occurs when proteins and sugars interact at high temperatures, and while it is responsible for the desirable brown color in roasted foods, it also results in a reduction in the nutritional quality of the proteins in plant-based beverages.
Most plant-based drinks already contain significantly less protein than cow’s milk. The UHT process further exacerbates this issue by modifying the already limited proteins, breaking down essential amino acids crucial for human health. For example, the study found that the UHT-treated cow’s milk contained 3.4 grams of protein per liter, while the majority of plant-based drinks contained between 0.4 and 1.1 grams of protein per liter. Additionally, the essential amino acid content in all plant-based drinks tested was lower than in cow’s milk.
Another concerning aspect of the UHT treatment is that it can introduce new compounds into the drinks. Among these are potentially harmful substances like acrylamide, a known carcinogen found in some plant-based drinks, particularly those made from roasted almonds and oats. The researchers detected acrylamide levels in four of the plant-based drinks tested, albeit at concentrations low enough not to pose an immediate health risk. However, when consumed regularly from various sources—such as bread, coffee, and fried potatoes—acrylamide exposure can accumulate to potentially dangerous levels over time. In addition to acrylamide, other harmful compounds like α-dicarbonyl compounds and hydroxymethylfurfural (HMF) were found in several of the plant-based drinks. These compounds are known to be reactive and may pose a risk if consumed in large quantities over time, though their levels in the drinks were not alarmingly high.
While the findings do not immediately suggest that these plant-based drinks are dangerous, they underscore an important concern regarding the chemicals generated during food processing. The Maillard reaction, while responsible for some of the desirable characteristics in cooked foods, can also lead to the formation of compounds linked to inflammation in the body, as well as an increased risk of chronic conditions such as diabetes and cardiovascular diseases. Although the human body can break down some of these compounds, there remain many others that are not well understood or have yet to be studied comprehensively.
Lars Ove Dragsted, a professor of nutrition, emphasizes that the study sheds light on the broader issue of ultra-processed foods. He suggests that more research is needed to understand the full implications of the Maillard reactions in food processing, particularly for plant-based and processed foods. The presence of these compounds highlights the need for more attention to the long-term health impacts of consuming such foods, especially when they are processed in ways that might compromise their nutritional value.
The study also has broader implications for the future of plant-based foods and the food industry as a whole. While the increased consumption of plant-based products is often seen as a positive move toward more sustainable and environmentally friendly diets, the process of converting raw ingredients into finished beverages or foods may inadvertently diminish their nutritional content. Professor Lund argues that the food sector’s green transition should not be based solely on substituting animal-based products with ultra-processed plant ingredients. Instead, she advocates for a food system that focuses on the least processed and most nutritionally beneficial foods possible. In this regard, her advice to consumers is to prepare as much of their own food as possible, rather than relying heavily on processed alternatives, including plant-based drinks.
The study also calls for action within the food industry. Professor Lund hopes that manufacturers will reconsider the extent of processing in plant-based beverages, possibly rethinking the necessity of UHT treatment in favor of products with shorter shelf lives. By reducing the level of processing, the industry could enhance the nutritional quality of plant-based beverages, making them more suitable alternatives to cow’s milk in terms of both environmental sustainability and nutritional value.
Overall, the findings of the study provide important insights into the plant-based beverage market, revealing the complex relationship between food processing, nutritional quality, and health. While plant-based drinks may offer some environmental advantages, they should not be viewed as automatic substitutes for cow’s milk in terms of nutrition. Consumers are encouraged to remain mindful of the products they choose, ensuring they obtain the necessary nutrients from a variety of foods and not solely from processed drinks. Furthermore, as the plant-based market continues to grow, it is essential that manufacturers prioritize the development of more nutritious, minimally processed alternatives that offer true health benefits alongside their environmental appeal.