1. Introduction
A visit to the dairy section of any major supermarket in the West will reveal the vast array of non-dairy plant-based beverages based upon a wide variety of plant products. The popularity of these products has dramatically increased over the past decade. A significant number of people living in Western countries limit or avoid dairy milk altogether for many reasons including milk protein allergies, lactose intolerance, personal and environmental health concerns, or from a desire to support their vegan lifestyle [
1]. Globally the dairy alternatives market was reported to be worth
$US12.1 billion in 2018 and is expected to reach
$US25.1 billion by the end of 2026 [
1]. The non-dairy milk industry in the US grew 61% from 2012 to 2018 [
2]. Millennials, who make up nearly one quarter of the US population, are reported to be the largest group to consume non-dairy milk with 77% of them buying the beverages regularly [
3].
Soy was the first dairy alternative beverage on the market and enjoyed substantial popularity. However, consumer confidence in soy fell significantly when unfavorable internet stories surfaced about the high isoflavone content of soy and its possible association with cancer. However, the use of soy has not been documented to be associated with an increased risk of breast cancer [
4]. Almond milk then grew in popularity before articles on the web touted the so-called health benefits of coconut and coconut beverage [
5]. With the steady popularity of almond beverage, additional beverages made from other nuts soon appeared on the market. Today, we have more than 20 non-dairy plant-based beverages from which to choose. These plant-based beverages can be made from nuts (e.g., almonds, cashews, hazelnuts), coconuts, grains (rice, oats), legumes (soy, peas), seeds (flax, hemp, sesame, chia), and fruits (banana). Almond, soy and coconut non-dairy beverages have been the recent market leaders, with the sales of oat-based beverages now experiencing a surge [
2]. Preferences for the beverages vary depending upon a number of factors such as the flavor, price, packaging, taste, nutritional profile, and whether the product is organic, and free of genetically modified (GM) ingredients [
6,
7].
Previous investigators have analyzed non-dairy beverages against dairy milk as a nutritional standard, with a special focus mostly on women and children. They conclude that the non-dairy beverages should not be considered nutritionally equivalent to dairy milk [
8,
9,
10,
11,
12]. In contrast to this, 69% of consumers believe that non-dairy plant-based beverages are healthy for their kids [
13].
Typically, a serving of plant-based dairy alternative beverage supplies less than 140–150 calories. This represents only 7–7.5% of a 2000 calorie intake for a day. A serving of 2% (reduced fat) milk would provide 124 calories. A non-dairy beverage is not usually considered a major source of calories. However, there are certain nutrients that are normally provided from the use of milk. It is imperative that a plant-based dairy alternative be adequately fortified with these essential nutrients, namely calcium, vitamins D and B12. For a vegetarian, these three nutrients may not be easily obtained in their diet in sufficient amounts without the presence of dairy milk. For the vegans, it is especially important since their diet is typically marginal in these three nutrients [
14].
Consumers, for health reasons, are often concerned about the level of sodium, saturated fat and sugars in the plant-based dairy alternative beverages. These nutrients can have an adverse effect upon one’s cardiovascular [
15,
16,
17] and metabolic health [
18], and body weight [
19]. Since the plant-based beverages are often used in place of dairy milk, some consumers desire the protein level to approximate the level in dairy milk, that is 8 g protein/serving. The presence of dietary fiber in a processed food is considered a positive thing. Its presence promotes gastrointestinal and cardiovascular health, and improves glycemia and insulin sensitivity in both diabetic and non-diabetic individuals [
20]. The addition of prebiotic fibers, such as chicory root extract, to some beverages is considered a healthy addition since they may also enhance immune function [
20].
The purpose of the present study was to conduct a cross-sectional survey of plant-based non-dairy beverages to assess the nutritional content and health profile of the plant-based beverages. The fortification level of calcium, vitamins D and B12 for each beverage was determined. In addition, the chemical form of calcium fortification was also documented since various calcium salts are known to have different bioavailability. Both calcium carbonate and tricalcium phosphate are commonly used, yet they have been shown to have different levels of absorption [
21]. The levels of protein, sodium, saturated fat, sugar, and dietary fiber in the plant-based beverages were also examined in an effort to measure the nutritional quality and health profile of each plant-based beverage.
In this study we were not only interested in the important nutritional and health pros and cons for using the different beverages but also to discover how the different types of beverages (grain, nut, seed, coconut and legume based beverages) varied in composition. Are the products typically fortified in a consistent pattern? Are there differences between the various products available from different parts of the Western world? Our results should help consumers make better informed choices.
2. Materials and Methods
The nutritional contents of 148 plant-based dairy milk alternatives were analyzed. This included 60 beverages (22 brands) from the Western USA, 48 beverages (11 brands) from Australia, and 40 beverages (16 brands) from Western Europe (in particular UK, France, and Spain). The beverages were selected, from October to December 2020, from those commonly available in selected supermarkets on the 3 continents, including Safeways (USA), Woolworths (Australia), Waitrose (UK) and Carrefour (Western Europe). Store beverages were photographed and additional beverages were added from the website of the retailer. All plant-based beverages observed in the stores and shown in the appropriate websites were considered except those beverages that had incomplete information on the nutrition label.
The nutritional content and ingredients were recorded from the nutrition label on the commercial package or from the information located on the website of the manufacturer or retailer. The nutrients per serving size which were available on all packages included calories, fat, saturated fat, sodium, dietary fiber, total sugars, protein, and the important micronutrients calcium, vitamin D, and vitamin B12. The calcium salt used in fortification and the form of gum (dietary fiber) used were also noted. The median values of the nutrients were calculated for each type of beverage and for the beverages grouped from each of the three continents. The median levels of fortification were calculated (for calcium, vitamin D, and vitamin B12 separately) for all beverages as well as separately for those that are actually fortified.
The nutritional value of each beverage was rated according to the following criterion: calcium, vitamin D and vitamin B12 content of at least 20% of Daily Value (DV)/serving; and at least 5 g of protein/serving. The health qualities portrayed by the ingredients were determined by the following criteria: not more than 5 g of total sugars/serving; not more than 1 g of saturated fat/serving; not more than 120 calories/serving; not more than 115 mg sodium/serving; and at least 1.5 g of dietary fiber/serving.
The US Dietary Guidelines specify, as a general guide, that 5% DV or less of a nutrient/serving is considered low, while 20% DV or more of a nutrient/serving is considered high [
22,
23]. In the USA the DV for calcium is 1300 mg, vitamin D is 20 mcg, vitamin B12 is 2.4 mcg, sodium is 2300 mg, protein is 50 g, added sugars is 50 g, saturated fat is 20 g, and dietary fiber is 28 g [
23]. For our analyses we considered a 20% DV (high level) as an adequate fortification for calcium, vitamin D and vitamin B12. For sodium and saturated fat we accepted that beverages should not exceed 5% of their DV (a designated low level), i.e., 115 mg for sodium (5% of 2300 mg) and 1 g of saturated fat (5% of 20 g). For European beverages, the sodium content was calculated from the given salt value using the formula that 2.5 g salt equals 1000 mg sodium. We suggest that beverages have at least 5% of DV for dietary fiber (approx. 1.5 g), at least 10% of the DV/serving for protein, and no more than 10% DV/serving for sugars. Ten percent was chosen as a mid-stream number between the 5% DV (low value) and the 20% DV (high value). This gave us a minimally acceptable level of 5 g protein/serving, and a level of 5 g sugars/serving to allow for some sweetening but not an excessive amount.
Statistical Analysis
The percentage of non-dairy plant-based beverages having been fortified with specific micronutrients (i.e., calcium, vitamin D and vitamin B12) and with specific nutritional requirements per serving (i.e., at least 5 g protein, no more than 1 g saturated fat, no more than 5 g total sugars, no more than 120 calories, no more than 115 mg sodium and at least 1.5 g dietary fiber) were detailed. Descriptive statistics (median and interquartile range) was stated for products by region and by type of beverage, as the normality of data distribution was firstly verified through the Kolmogorov-Smirnov test and rejected. The Kruskal–Wallis test for independent samples was used to evaluate variability in calories and nutrients of interest per serving among groups, followed by Bonferroni adjustment for multiple comparisons. The statistical analysis was performed through the IBM SPSS Statistics 27.0.1.0 (Armonk, NY, USA: IBM Corp.) with the significant level set at p < 0.05.
3. Results
The plant-based beverages analyzed were based upon almonds (n = 33), soy (n = 29), oats (n = 23), rice (n = 13), coconut (n = 10), cashews (n = 7), pea protein (n = 7), hazelnuts (n = 3), macadamia (n = 3), flax (n = 2), quinoa (n = 2), hemp (n = 1), and the following mixtures: almond and coconut (n = 6), pea and almond (n = 2), oats and pea (n = 1), pea, almond and cashew (n = 1), rice and hazelnut (n = 1), rice and coconut (n = 1), oats and walnut (n = 1), hazelnuts, walnut and almond mix (n = 1), and soy and rice (n = 1).
The analyses of the nutritional composition and health profile of the 148 plant-based non-dairy beverages are summarized in
Table 1,
Table 2,
Table 3,
Table 4,
Table 5,
Table 6 and
Table 7. From the data shown in
Table 1 we see that the beverages are more commonly fortified with calcium (78%) than with vitamins D (53%) or B12 (41%). Fortification generally occurs more frequently for products sold in the USA than in Australia and Europe. This is most marked for vitamin D. Frequency of vitamin D fortification is especially poor in Australia (21%) compared with the USA (82%). In addition, vitamin B12 fortification is below 50% in all 3 regions.
A level of 20% DV or more is considered high for a nutrient by the US Dietary Guideline standards [
23]. When all the beverages were examined against this standard we found that most of the products that were fortified reached that 20% DV standard for calcium (70%), while B12 fortification achieving the 20% DV level were only 35–40% of the beverages, and vitamin D fortification to the 20% DV standard were remarkably low (24%) (
Table 1). In fact, less than 10% of the beverages sold in Europe and Australia contained vitamin D at the 20% DV level. Even after eliminating the non-fortified beverages from the statistical calculations, the median levels of vitamin D in all 3 regions were low (9–22% DV) (
Table 2).
Mean values of calories and four selected nutrients (saturated fat, protein, sugars, and sodium) in the beverages are tabulated in
Table 3. The beverages as a whole appeared modest in calories (median: 93 kcal/serving), sodium (median: 100 mg/serving), and sugar content (median: 4.6 g/serving), and low in saturated fat (median: 0.5 g/serving) and protein (median: 1.8 g/serving). Twenty-four (16%) of the beverages were labeled as unsweetened. No differences in the protein content or sugar level was detected among countries (
p = 0.055 and
p = 0.056, respectively). The energy content of Australian beverages appeared higher than the American ones, and their sodium content higher than that of the European beverages.
Table 4 and
Table 5 reveal the number of beverages with a healthy profile, as defined by their saturated fat, sugar, sodium, calorie, protein, and dietary fiber levels/serving. The data is broken down by region (
Table 4), and by type of beverage (
Table 5). While fewer than 30% of the beverages overall contained significant levels of dietary fiber (at least 1.5 g per serving), 55% of the beverages contained no more than 5 g sugars/serving, 64% contained no more than 115 mg sodium/serving, 74% contained no more than 120 calories/serving, and 87% contained no more than 1 g saturated fat/serving. By contrast, only 26% of the beverages contained at least 5 g protein/serving. Only the beverages based on soy or pea protein had levels of protein in excess of 5 g/serving. In addition, the beverages based on soy, oats, and macadamia were likely to have higher levels of dietary fiber. Only beverages based on pea protein had more than half their products with sodium levels over 115 mg/serving. Most of the beverage types had more than half of their products with 5 g or less of sugars/serving. Beverages based upon rice, hazelnuts, and oats were the exceptions.
Protein levels varied considerably among the various types of beverages (
Table 6). While 1 in 4 beverages contained at least 5 g protein/serving (
Table 4), the protein levels varied from 0.1 g/serving for coconut to 8–9 g/serving beverages having either soy or pea protein as their base (
Table 6). The grain-based beverages ranged from 0.8 g protein/serving for rice to 2.0 g/serving for oats. Nut-based beverages contained protein levels of 1.0–1.3 g/serving (
Table 6).
The analyses described below are concerned with issues of fortification.
Supplemental Tables S1 and S2 show selected nutrient values for all of the beverages, both fortified and non-fortified products, by world region (
Table S1) and by beverage type (
Table S2). Calcium fortification varied among the beverages 2-fold (
Table 7). Beverages based upon coconut and cashews had a median value of 16% DV; oats and rice beverages 25% DV; soy and pea-based beverages 30% DV; and almond beverages were 35% DV of calcium/serving. While 60% of beverages overall were not fortified with vitamin B12, the lack of B12 was especially noticeable in almond-based beverages (7/33 fortified), cashew-based (3/7 fortified), oats-based (10/23 fortified), rice-based (6/13 fortified), and beverages from mixed sources (2/14 fortified). Of the fortified beverages, soy, almond and cashew beverages had a median value of 50% DV of vitamin B12/serving while pea, coconut and oat-based beverages had a median value of 35–39% DV, and rice beverages 25% DV for vitamin B12 content/serving (
Table 7). The lack of vitamin D fortification by beverage type was very similar to that seen for vitamin B12. Almond, almond-coconut blend, cashew and rice beverages had less than 50% of their products fortified with vitamin D. Among the fortified beverages, the lowest vitamin D levels were seen in hazelnut, coconut and almond beverages (9–12% DV/serving), and the oats, rice and soy beverages (15% DV/serving) (
Table 7).
We noticed that there was a fortification pattern observed among the manufacturers. Some brands appear fortified with calcium and the two vitamins (D and B12) while other brands consistently lack 2 or all 3 nutrients.
Only 115 of the 148 products were fortified with calcium, and of those reporting the calcium salt used for fortification, tricalcium phosphate was the most commonly used (44%), followed by calcium carbonate (38%). Sixteen percent of the products were fortified with both tricalcium phosphate and calcium carbonate. Calcium chloride and calcium hydroxide were each used once in a beverage. Many products contained no added fiber and those that had added fiber components often contained 2 to 3 different sources. Most of the dietary fibers added to beverages provide functional properties (as a stabilizer/thickener) rather than for any stated nutritional value. An exception to this was any beverage labeled as prebiotic. The website of the food company claimed these products improved gut health. Of the 82 products reporting the addition of fiber, gellan gum (83%) was the most popular addition, followed by locust bean gum (26%), xanthan gum (20%), and guar gum (13%). Seven reported carrageenan, five reported chicory root extract (those labeled as “prebiotic”), four reported gum arabic (acacia gum). Others reported the addition of citrus fiber, sodium alginate, marine algae, or cellulose.
In addition to the nutrients listed above, a few of the beverages showed the presence of other nutrients: riboflavin (n = 22), vitamin E (n = 8), thiamine (n = 7), vitamin A (n = 4), zinc (n = 3), and selenium, magnesium, copper, pyridoxine, folic acid (1 product each).
5. Conclusions
The rising popularity of a vegan lifestyle will continue to fuel the consumer demand for non-dairy plant-based beverages [
1]. The plant-based beverages surveyed across 3 continents generally scored well in terms of containing modest levels of sodium and calories, and low levels of saturated fat. While beverages in US tended to have fewer calories, and European beverages tended to have lower sodium values, the differences were not dramatic. We found that pea-based beverages had the most sodium added, while coconut, hazelnut, and soy averaged the lowest levels of sodium. Furthermore, the grain beverages (such as rice and oats) had more sugar than other beverages types, while coconut, cashew, pea, and almond beverages had the lower sugar levels. All of the beverages had low levels of saturated fat with the exception of coconut beverages.
Almost 80% of the beverages were fortified with calcium, and 55% of the beverages were fortified to levels equal to or better than the calcium level of dairy milk. We found that almond, soy and pea-based beverages had the highest levels of calcium while coconut and cashew beverages had the lowest levels. The soy and pea protein-based beverages had 8–9 g protein/serving, comparable to the level in dairy milk, while rice and coconut-based beverages had less than 1 g of protein/serving.
Levels of vitamins D and B12 fortification were quite low. Since these beverages are significantly used by vegetarians, who are often marginal or deficient in vitamin B12, it is unfortunate that only 41% of all products examined had vitamin B12 fortification. Australian and European beverages had considerably lower levels of both vitamins D and B12. Among the beverages that were B12 fortified, we found rice beverages had the lowest content of vitamin B12, while soy, pea, cashew and almond beverages had the highest content of vitamin B12. For the beverages that were vitamin D fortified, almond and coconut beverages had the lowest content of vitamin D, while pea protein had the highest. Food manufacturers of plant-based beverages must be encouraged to better fortify their products with essential nutrients.
Many of the non-dairy plant-based beverages have significant health-promoting properties. Consumers need to be better informed regarding the nutritional content of non-dairy plant-based beverages as their nutrient profiles can vary greatly between the different types of beverages. Information about the health benefits of the beverages may also help consumers make healthier choices.