Milk has long been a fundamental part of many people’s diets worldwide. It is prized for its rich content of essential nutrients such as protein, calcium, and various vitamins that support growth, bone health, and overall well-being.
However, in recent years, plant-based milk alternatives have become increasingly popular, driven by factors such as lactose intolerance, milk allergies, environmental concerns, and ethical reasons. These alternatives include soy, almond, oat, coconut, and other plant-derived milks.
Despite their growing availability and popularity, many consumers wonder how these plant-based milks compare nutritionally to traditional dairy milk. To address this question, a cross-sectional study was conducted by researchers who examined the nutrient composition of dairy milk and plant-based milk alternatives sold in supermarkets in Australia and Singapore.
This study offers valuable insights into the similarities and differences in nutrient content between these products, as well as how they vary across countries with different food cultures and supply chains. Understanding these differences is crucial for consumers who want to make informed dietary choices and for health professionals who provide nutrition advice.
Nutritional Importance of Milk and Its Alternatives
Milk is a rich source of energy, high-quality protein, calcium, and vitamins such as A, B2, and B12, along with minerals like iodine, phosphorus, and zinc. These nutrients play vital roles in supporting bone growth, muscle development, and overall health.
Dairy milk naturally contains these nutrients in balanced amounts, making it a reliable source for many people. However, not everyone can or wants to consume dairy milk. Lactose intolerance, which affects a large portion of the global population, makes digesting dairy difficult for some individuals.
Others avoid dairy products due to allergies, ethical concerns regarding animal welfare, or the environmental impact of dairy farming. Plant-based milk alternatives have emerged as popular substitutes, often marketed as healthier or more sustainable options.
Yet, their nutrient content can vary widely depending on the source ingredients and manufacturing processes. Plant-based milks do not naturally contain the same levels of protein or calcium as cow’s milk. To make them more nutritionally comparable, many manufacturers add vitamins and minerals through a process called fortification.
However, the extent and consistency of fortification differ between brands and countries. Therefore, comparing the nutrient content of dairy and plant-based milks in different markets helps consumers and health professionals understand their nutritional adequacy and make better choices.
In this study, researchers collected data on milk and plant-based milk alternative products from supermarkets in Australia and Singapore. They gathered information from product packaging labels, recording nutrient contents such as protein, fat, sugar, calcium, energy (calories), and other micronutrients.
The products were categorized into three main groups: plain milks, which are unflavored dairy or plant-based milks; flavored milks, which include added flavors such as chocolate or strawberry; and breakfast drinks, which are products marketed as convenient breakfast options and often contain added nutrients.
Altogether, the study included 903 products, with approximately two-thirds being dairy milks and one-third plant-based alternatives.
Statistical analyses were performed to compare nutrient levels across product types and between the two countries. The findings revealed several important differences and similarities that are worth exploring in detail.
Key Nutritional Differences Between Dairy and Plant-Based Milks
One of the most striking differences was in protein content. Protein is a critical nutrient for muscle repair, growth, and many bodily functions. The study found that dairy milks contained significantly higher protein levels than plant-based alternatives.
Specifically, the median protein content in dairy milk was 3.3 grams per 100 milliliters, whereas plant-based milks averaged only 1.0 gram per 100 milliliters. This means that dairy milk has more than three times the protein found in most plant-based milks.
Among the plant-based options, soy milk stood out as having the highest protein content, making it the closest alternative to dairy milk in this regard. Other plant-based milks, such as almond, oat, and coconut, had much lower protein levels, which may be insufficient to meet the protein needs of some consumers if these milks are used as the primary milk source.
Fat content also differed between dairy and plant-based milks. Dairy milks contained nearly four times the median saturated fat content compared to plant-based milks, with 1.1 grams versus 0.3 grams per 100 milliliters, respectively.
Saturated fat is known to raise cholesterol levels and increase the risk of heart disease when consumed in excess. Plant-based milks generally had lower saturated fat levels, except for coconut milk, which naturally contains higher saturated fat due to its composition.
Total fat content was also higher in dairy milks, but fat levels varied widely among plant-based milks depending on their source ingredients. For example, oat and almond milks tend to have lower fat, while coconut milk has higher fat content.
Sugar content showed significant variation, especially between plain and flavored products. Flavored milks, whether dairy or plant-based, contained almost double the median sugar compared to plain milks, with 8.3 grams versus 4.6 grams per 100 milliliters.
This finding is important because excessive sugar intake is linked to obesity, diabetes, and dental problems, particularly in children. When comparing plain dairy milk to plain plant-based milks, dairy milk had more than double the sugar content (5.1 grams versus 2.6 grams per 100 milliliters).
However, it is worth noting that most of the sugar in dairy milk is lactose, a natural sugar, while plant-based milks may contain added sugars unless labeled as unsweetened. Therefore, consumers should carefully read product labels to avoid unnecessary added sugars.
Calcium is another key nutrient that plays a vital role in bone health. Dairy milk naturally contains high levels of calcium, making it a reliable source for many people. Most plant-based milks do not naturally contain much calcium, so manufacturers often fortify them to make them more comparable to dairy milk.
The study found that calcium content was generally similar between dairy and plant-based milks, especially in products that had been fortified. This was consistent in both Australia and Singapore.
However, it is important to note that not all plant-based milks are fortified, so consumers should check labels to ensure they are getting enough calcium, particularly if they rely on these products as a primary milk source.
Energy content, measured in calories, and carbohydrate levels also showed differences between products sold in Australia and Singapore. Generally, products sold in Australia had higher energy, protein, and fat content but lower carbohydrate content compared to those sold in Singapore.
These differences may be due to variations in product formulations, consumer preferences, and food regulations in the two countries. For instance, Singaporean products often contained more carbohydrates, which might be related to sweeter formulations or different ingredient use.
The study also highlighted differences in the variety and types of milk products available in the two countries. Singapore had a greater variety of both dairy and plant-based milk products, including a higher proportion of breakfast drinks.
This variety may be explained by Singapore’s status as a small island nation that imports most of its food, leading to a diverse selection to meet the preferences of its multicultural population. In contrast, Australia, as a large dairy producer, had a higher availability of traditional dairy products.
Role of Fortification in Nutritional Adequacy
Fortification standards and practices emerged as a key factor influencing the nutritional adequacy of plant-based milks. Fortification involves adding vitamins and minerals such as calcium, vitamin A, vitamin D, vitamin B2 (riboflavin), and vitamin B12 to plant-based milks to make them nutritionally comparable to dairy milk.
The study found that many plant-based milks are fortified, but the level and consistency of fortification vary widely.
Research from other sources suggests that ideal plant-based milk alternatives should contain approximately 85 to 100 kilocalories per 100 milliliters, at least 2.2 grams of protein per 100 milliliters (preferably around 2.8 grams), low saturated fat (less than 0.75 grams per 100 milliliters), low added sugar (ideally below 3 grams per 100 milliliters), and fortification with calcium and vitamins A, D, B2, and B12 at levels similar to dairy milk.
Unfortunately, only a small percentage of plant-based milks currently meet these standards, with fortified soy and pea milks being the closest.
Furthermore, these findings have important health implications. The lower protein content in most plant-based milks means that consumers who rely on these alternatives need to ensure they get enough protein from other foods.
This is especially crucial for children, adolescents, pregnant women, and older adults who have higher protein needs. The higher sugar content in flavored milks raises concerns about excess sugar consumption, which can contribute to obesity and dental problems.
Fortification helps bridge nutrient gaps but requires consistent regulation and consumer awareness to be effective.mWhile plant-based milks offer benefits such as lower saturated fat and suitability for lactose-intolerant individuals, they generally have lower protein quality and quantity compared to dairy milk.
Among plant-based options, only soy and pea milks provide protein levels comparable to dairy milk. Many plant-based milks also vary widely in energy content and micronutrient levels, so consumers should read labels carefully and choose fortified products with adequate protein and low sugar.
Emerging food technologies are advancing the development of plant-based milks with improved nutritional profiles by combining multiple plant proteins, healthy fats, and fortification. Novel ingredients like quinoa, chickpeas, and algae oils are being explored to create more balanced alternatives.
Additionally, regulatory bodies and health organizations are working to establish nutrient standards for plant-based milks to ensure they are not nutritionally inferior to dairy milk.
Conclusion
In conclusion, this comprehensive study comparing dairy milk and plant-based milk alternatives in Australia and Singapore reveals important nutritional differences. Dairy milk contains significantly more protein and saturated fat, while plant-based milks generally have lower protein and fat but can be fortified to match calcium and vitamin content.
Consumers should be aware of these differences and choose products that meet their nutritional needs, especially regarding protein and calcium. Fortification plays a key role in making plant-based milks suitable dairy alternatives. Understanding the nutrient composition of these products helps consumers make informed choices and supports public health efforts to provide clear guidance on milk and milk alternative consumption.
Key Terms and Concepts
What is Cross-Sectional Study: A type of research that collects and analyzes data from a specific population at a single point in time. It’s important because it provides a “snapshot” of a situation, allowing researchers to describe characteristics or compare groups quickly without waiting for changes to happen. Researchers use it to understand what is happening right now. For instance, this milk study used a cross-sectional design to compare the nutrient content of products available on supermarket shelves in Australia (2019) and Singapore (2020) at those specific times, analyzing 903 products. There isn’t a specific formula for conducting the study itself, but it answers questions like “What is the current range and nutritional profile of milk products in these countries?”
What is Plant-Based Milk Alternative (PBMA): A beverage made from plant sources (like nuts, seeds, grains, or legumes) designed to be used similarly to cow’s milk. It’s important because it provides an option for people who cannot or choose not to consume dairy milk due to allergies (like milk protein allergy), intolerance (like lactose intolerance), ethical concerns (animal welfare), environmental reasons, or health perceptions. The study used this term to categorize non-dairy products like soy milk, almond milk, oat milk, and coconut milk drinks. Examples include the almond milk popular in Australia (43% of PBMAs there) and the soy milk dominant in Singapore (51% of PBMAs there). There is no defining formula, but it’s characterized by its plant-derived ingredients.
What is Fortification: The process of adding vitamins, minerals, or other nutrients to a food product that weren’t originally present, or were present in lower amounts. It’s crucial because it improves the nutritional value of food, especially for products like PBMAs that naturally lack key nutrients found abundantly in dairy milk, such as calcium and vitamin D. The study examined fortification to see how well PBMAs matched dairy nutritionally, finding that 65% of PBMAs were fortified (compared to only 20% of dairy milks), with calcium being the most common addition (e.g., added to 69% of fortified Australian PBMAs). While fortification levels are declared on labels (e.g., “Calcium: 120mg per 100ml”), there isn’t a single formula; it depends on the nutrient and regulatory standards.
What is Median: The middle value in a list of numbers ordered from smallest to largest. It’s important because it gives a better idea of a “typical” value than the average when the data includes very high or very low numbers that could skew the result. Researchers used the median to summarize the nutrient content of milk products in this study, as nutrient data often isn’t evenly distributed. For example, the median protein content in dairy milk across the study was 3.3 grams per 100ml, meaning half the dairy products had more protein than this and half had less. The formula involves sorting all values and selecting the one in the middle (or averaging the two middle values if there’s an even number).
What is Nutrient Density: A measure of how much nutrition (vitamins, minerals, protein) a food provides relative to its calorie content. It’s important because it helps identify foods that offer significant nutritional benefits without excessive calories, supporting overall health and meeting dietary needs efficiently. Dairy milk is often described as nutrient-dense; the study implicitly used this concept when highlighting dairy’s naturally high levels of protein, calcium, and other micronutrients compared to many unfortified PBMAs. An example is 100ml of plain dairy milk providing around 3.3g protein and 120mg calcium for roughly 65 calories. While not a single formula, it can be thought of as the amount of nutrients per calorie.
What is Lactose Intolerance: A condition where a person has difficulty digesting lactose, the natural sugar found in milk and dairy products, due to a deficiency of the enzyme lactase. It’s important because it causes uncomfortable symptoms (like bloating, gas, diarrhea) and is a primary reason many people seek out PBMAs. The study mentions this as a key driver behind the demand for PBMAs, particularly noting higher rates of lactase deficiency among Asian populations, which helps explain the greater proportion and variety of PBMAs available in Singapore. An example is someone choosing soy milk for their coffee instead of regular cow’s milk to avoid digestive issues. There is no specific formula for lactose intolerance.
What is Interquartile Range (IQR): A measure of statistical spread that shows where the middle 50% of data points lie. It’s calculated as the difference between the 75th percentile (value where 75% of data is below) and the 25th percentile (value where 25% of data is below). The IQR is important because it indicates how varied or consistent the data is around the median, providing a clearer picture than just the range (min to max), especially for skewed data. The study used IQR alongside the median to describe the variation in nutrient values. For example, the protein content in PBMAs had a median of 1.0g/100ml and an IQR of 0.6g to 3.0g/100ml, meaning half of all PBMA products fell within this protein range. The formula is IQR = Q3 (75th percentile) – Q1 (25th percentile).
What is Statistical Significance (p-value): A measure used in statistics to determine if the difference or relationship observed in a study is likely real or could have just happened by random chance. A p-value less than 0.05 (p<0.05) is commonly considered statistically significant, meaning there’s less than a 5% probability the result is due to randomness. It’s crucially important because it helps researchers decide if their findings are trustworthy and meaningful. The study used p-values (e.g., p<0.0001, p=0.005) to confirm that differences observed – like dairy milk having much higher protein than PBMAs or flavored products having more sugar than plain ones – were very unlikely to be random fluctuations. The p-value itself is calculated using statistical formulas (like those in the Mann-Whitney U or Kruskal-Wallis tests).
What is Saturated Fat: A type of dietary fat molecule where the carbon atoms are fully saturated with hydrogen atoms. It’s important because consuming high amounts is linked to an increased risk of heart disease by raising levels of “bad” LDL cholesterol in the blood. The study found a significant difference: dairy milk had a median saturated fat content nearly four times higher (1.1g/100ml) than plant-based milk alternatives (0.3g/100ml). An example of a PBMA that can be higher in saturated fat is coconut milk. While listed on nutrition labels (e.g., “Saturated Fat: 0.5g”), there isn’t a consumer formula; it’s inherent to the fat source.
What is Apparent Consumption: An estimate of how much of a food or beverage is consumed by a population, typically calculated using data on production, imports, exports, and stock changes. It’s important for understanding food supply trends and dietary patterns at a population level when direct consumption surveys are unavailable. The study used this concept, citing Australian Bureau of Statistics data showing apparent consumption of almond milk in Australia rose 31% and soy milk 16% between 2018-19 and 2019-20. An example formula used nationally is: Apparent Consumption = Production + Imports – Exports – Change in Stocks.
What is Kruskal-Wallis Test: A statistical test used to determine if there are significant differences between the medians of three or more independent groups, especially when the data isn’t normally distributed. It’s important because it allows researchers to compare multiple categories reliably without relying on assumptions required by tests like ANOVA. The study used the Kruskal-Wallis test to compare the nutrient profiles across the three sub-categories: breakfast drinks, plain milks/alternatives, and flavored milks/alternatives. For instance, it confirmed the significant difference in sugar content among these groups (p=0.005). The test works by ranking all the data and comparing the average ranks of the groups.
What is FoodTrack™ Database: A systematic database developed by CSIRO (Commonwealth Scientific and Industrial Research Organisation) in partnership with the National Heart Foundation of Australia, designed to collect detailed information on packaged food and beverages available in retail environments. It’s important because it provides a standardized, high-quality method for capturing real-time product data (nutrients, ingredients, prices, images) directly from packaging, enabling consistent monitoring and cross-country comparisons. The study relied on the FoodTrack™ infrastructure and methodology to collect data consistently in both Australian and Singaporean supermarkets and convenience stores. An example is using a custom app with barcode scanning to record the protein content and ingredient list of a soy milk carton. There is no formula for the database itself.
What is Mandatory Warning: A statement required by law or regulation to be displayed on a product’s packaging to inform consumers about specific risks, limitations, or important usage instructions. It’s vitally important for consumer safety and ensuring informed choices, particularly for products that might be mistakenly considered direct substitutes when they are not nutritionally equivalent. The study mentions the Food Standards Australia New Zealand (FSANZ) mandatory warning for plant-based milk alternatives: “that the product is not suitable as a complete milk replacement for children under 5 years old.” This highlights the key nutritional gaps, especially in protein and micronutrients, found in many PBMAs compared to dairy milk. There is no formula for a mandatory warning.
What is Median Protein: The middle value of protein content found when all measured protein values from a group of products are arranged in order from lowest to highest. It’s important because it gives a more robust indicator of the typical protein level than the average, especially when some products might have very high or very low protein, providing a clearer picture for consumers and nutritionists. The study reported the median protein content to compare dairy milk and PBMAs, finding a stark difference: dairy milk median protein was 3.3g/100ml, while PBMA median protein was only 1.0g/100ml. An example contrast is cow’s milk consistently being high in protein versus rice milk typically being very low. The formula is the same as for any median: sort values and find the middle one.
What is Calcium Fortification: The specific process of adding calcium to a food or beverage product. It’s critically important for plant-based milk alternatives because they naturally contain very little calcium, unlike dairy milk which is a rich natural source essential for bone health. Fortifying PBMAs with calcium allows them to better approximate the nutritional value of dairy milk in this key mineral. The study found calcium was the most common fortificant added, present in 69% of fortified PBMAs in Australia and 53% in Singapore, helping the median calcium content of PBMAs match that of dairy milk (around 120mg/100ml). An example is almond milk with “Calcium (Mineral): 120mg” listed on its nutrition panel. While the added amount is declared, there isn’t a standard formula; manufacturers aim for levels comparable to dairy milk.
What is Market Proliferation: The rapid increase in the number and variety of products available within a specific market category. It’s important as it reflects consumer demand, industry innovation, and competition, but can also lead to consumer confusion. The study observed market proliferation in the milk alternatives category, particularly noting that Singapore had 30% more products overall (529 vs Australia’s 374) and a significantly wider variety of plant sources and breakfast drinks (e.g., 75 breakfast drinks in Singapore vs 32 in Australia). This difference was partly attributed to cultural factors like Singaporeans potentially being less overwhelmed by choice. There is no specific formula for market proliferation.
What is Flavored vs Plain: A categorization of milk and milk alternatives based on whether they have added flavorings (like chocolate, vanilla, strawberry, coffee) and usually added sugars, versus being in their natural, unflavored state. It’s important because flavoring significantly impacts nutritional content, especially sugar and calorie levels, affecting dietary choices related to weight management and conditions like diabetes. The study found flavored products (both dairy and plant-based) contained almost double the median sugar content (8.3g/100ml) compared to plain products (4.6g/100ml). An example is choosing a plain soy milk over a chocolate-flavored soy milk to avoid the high added sugar content in the flavored version. There is no formula; it’s defined by the presence of flavor additives and typically higher sugar.
What is Mann-Whitney U Test: A statistical test used to determine if there is a significant difference between the medians of two independent groups when the data is not normally distributed. It’s important because it provides a reliable non-parametric method for comparing two samples, like products from two different countries. The study used the Mann-Whitney U test for pairwise comparisons, such as directly comparing the nutrient profiles of dairy milk vs PBMAs, or products sold in Australia vs those sold in Singapore. For example, it confirmed that PBMAs sold in Australia had significantly lower sugar content (median 1.9g/100ml) than those sold in Singapore (median 3.5g/100ml) with p<0.0001. The test works by ranking all data points from both groups together and comparing the sum of ranks for each group.
What is Vitamin D Fortification: The specific process of adding vitamin D to a food or beverage. It’s important because vitamin D is crucial for calcium absorption, bone health, and immune function, and many people don’t get enough from sunlight or diet alone. Fortification helps address deficiencies. The study found a striking difference: Vitamin D fortification was far more common in Singaporean products (both dairy and PBMA) than in Australian ones. This reflects a public health need, as research cited showed nearly half of Singaporean adults were Vitamin D deficient despite the sunny climate, compared to an estimated 20% in Australia. An example is a fortified soy milk listing “Vitamin D” on its ingredients and nutrition panel. There is no standard formula; added amounts vary by product and regulation.
What is Mixed-Plant Milk: A plant-based milk alternative made by blending two or more different plant sources (e.g., almond and oat, or soy and coconut). It’s important as it represents innovation in the PBMA category, potentially aiming to improve taste, texture, or nutritional balance. The study identified 71 mixed-plant milk products (22% of all PBMAs), with significantly more found in Singapore (56) than Australia (15). These blends ranged from two plants (63%) up to six plants (8%), and the majority (76%) were plain, unflavored varieties. An example product might be “Almond & Oat Blend Beverage”. There is no defining formula, only the combination of multiple plant bases.
What is Nutrient Information Panel (NIP): A standardized label on packaged food products that lists key nutritional components, usually including energy (kilojoules), protein, fat (total, saturated), carbohydrates (total, sugars), and sodium, and often includes selected vitamins and minerals like calcium. It’s vitally important because it allows consumers to compare products, make informed dietary choices based on their health needs, and understand what they are consuming. The study relied entirely on data collected from the NIP on product packaging for its analysis of energy, protein, fat, carbs, sugar, and calcium content. An example is the table on the side of a milk carton showing “Per 100ml: Protein 3.5g, Fat 3.4g, … Calcium 120mg”. There is no formula; it’s a mandatory declaration following regulatory formats.
What is Non-Parametric Test: A type of statistical test that does not assume the underlying data follows a specific distribution (like the normal distribution). It’s important because many real-world datasets, including nutrient content values as found in the milk study, are not normally distributed; using non-parametric tests like the Kruskal-Wallis or Mann-Whitney U provides valid results without relying on potentially false assumptions. The study explicitly used non-parametric tests (confirmed by the Shapiro-Wilk test and visual inspection showing non-normal data) to analyze nutrient differences between milk types, sub-categories, and countries. Using a parametric test (like t-test or ANOVA) on this non-normal data could have given misleading results. These tests work primarily by analyzing the ranks of the data rather than the raw values.
What is Outlier: A data point that differs significantly from other observations in a dataset. It’s important because outliers can distort statistical summaries (like averages) and potentially skew the results of analyses if not handled appropriately. The study described identifying outliers using minimum and maximum values and boxplots, then checking the original product images to verify if the value was correct or needed correction. For example, an extremely high protein value in a rice milk (which is normally low protein) might be flagged as a potential outlier and checked. While there are statistical formulas to identify outliers (like points beyond 1.5*IQR from the quartiles), the study used visual inspection and verification.
What is Primary Ingredient: The main component or source material used to make a product. In the context of milk alternatives, it refers to the dominant plant source. Identifying the primary ingredient is important for categorizing products, understanding their base characteristics, and meeting consumer expectations about flavor and nutrition. The study determined the primary ingredient for PBMAs, even for blends, to compare product ranges between countries. This revealed that soy was the primary source for 51% of Singaporean PBMAs, while almond was primary for 43% of Australian PBMAs. An example is classifying an “Oat & Almond Beverage” where oats are listed first and make up the largest proportion as primarily an oat milk. There is no formula; it’s based on the ingredient list order and relative amounts.
What is Ready-to-Drink (RTD): A beverage product that is sold in its final consumable liquid form, requiring no preparation like mixing powder with water or brewing. It’s important for convenience and reflects consumer demand for on-the-go consumption. The study included RTD products in its data collection and analysis. While powdered milks requiring reconstitution were also collected initially, only products presenting nutrition information for their ready-to-drink form were included in the final nutrient analysis. Most products analyzed (like standard milk cartons or tetra packs) are RTD. An example is a carton of soy milk bought off the shelf and consumed directly. There is no formula; it’s a product format.
Reference:
Brooker, P. G., Anastasiou, K., Smith, B. P., Tan, R., Cleanthous, X., & Riley, M. D. (2023). Nutrient composition of milk and plant-based milk alternatives: A cross-sectional study of products sold in Australia and Singapore. Food Research International, 173, 113475. https://doi.org/10.1016/j.foodres.2023.113475
