September 2018 Issue
The Coup in the Dairy Aisle
By KC Wright, MS, RDN
Today's Dietitian
Vol. 20, No. 9, P. 28
Americans Have Gone Nuts (and Grains) for Plant Milks
Not that long ago, soy, almond, rice, and coconut milks were novelty beverages. Now, they're considered standard stock among a store's plant-based milk inventory. Today there are more plant-based milks than ever and likely more to come. Already the plant-based milk market has grown to include banana, cashew, flaxseed, hazelnut, hemp seed, macadamia nut, oat, pea, peanut, pecan, potato, quinoa, and walnut milks. Even lupine seed milk is sprouting up in Germany and is being sold in some European grocers.
This year, the global market for plant-based milks is forecast to top a staggering $16 billion—an astounding increase from $7.4 billion in 2010, according to data from Innova Market Insights. And the trend is expected to continue to surge through 2022.1 Much of this growth can be attributed to the fact that almond milk has surpassed soymilk as America's favorite cow's milk substitute, with a skyrocketing 250% sales growth from 2010 to 2015.2 Though market sales of coconut, rice, and other plant-based milks lag behind soymilk, consumers still spend tens of millions of dollars on these beverages. And, as consumers narrow their focus on taste and dietary preferences, an array of innovative substitutes for cow's milk will continue to pour into the market.
Prioritizing Plants
Along with plant-based beverages, plant-based diets are gaining prominence among consumers, with almost 40% of Americans actively seeking more plant-based foods to include in their diets.3 Currently, almost one-half of Americans consume plant-based milks, including 68% of parents and 54% of people younger than 18.4
There are many motivations driving consumers to choose plant-based milks over cow's milk, including health, ethical, and environmental concerns. The most common medical reason for avoiding cow's milk is allergy among infants and children.5 Approximately 2.2% to 3.5% of all infants are allergic to cow's milk because of its protein, though recent studies conducted on a large scale demonstrated that 35% of these infants outgrow their allergenicity towards milk by age 5 to 6. This may further increase to 80% by the time they reach the age of 16.6
After infancy, approximately 65% of the human population has a reduced ability to digest lactose, the sugar in cow's milk. Lactose intolerance in adulthood is more prevalent in people of East Asian descent, affecting more than 90% of adults in these communities, and is also common in people of West African, Arab, Jewish, Greek, and Italian descent.7
Some consumers prefer to drink nondairy beverages because they see them as nutritious—more so than dairy milk.3 Others shun cow's milk with the perception that plant-based milks are more heart healthy and better for weight loss, although there's no consistent research to support these claims.
From a sustainability standpoint, avoiding dairy (and meat) has been called the single biggest way to reduce the environmental impact on the planet, according to scientists behind a comprehensive analysis on the impact of farming. This new research shows that while farm livestock provides just 18% of calories and 37% of protein in the food supply, it uses the vast majority (83%) of farmland and produces 60% of agriculture's greenhouse gas emissions.8
Then there are dietary preferences; about 6% of the population across the United States consider themselves to be vegetarians, while 3% follow a strictly vegan lifestyle, thus avoiding milk from animals. The number of consumers adopting vegetarian or vegan diets is increasing, predominantly among young and diverse consumer groups.3
Finally, the decline in cow's milk consumption also is attributed to a generational shift decades in the making. With all else constant (including race and income), succeeding generations of Americans have consumed less milk than their preceding generations, reflected mainly in changes in frequency of consumption. Between the 1970s and 2000s, people have become less likely to drink milk at mealtimes, especially at lunch and dinner. Since 1970, per capita milk consumption has fallen from 0.96 cups per day to between one-half and two-thirds of a cup daily.9
In fact, according to a recent study by the Centers for Disease Control and Prevention, less than one-third of 15,000 high school students surveyed drink a glass of milk per day.10 Over the past few decades, teens have shifted from milk to soda, then to Gatorade and other sports drinks, and recently to energy drinks such as Monster and Red Bull.10
Declining Dairy
Simultaneous to the surge in plant-based milks, sales of dairy milk decreased 7% in 2015—by $17.5 billion—and are projected to drop another 11% through 2020.4 In 2013, dairy milk dominated the market share at 90.5%, while plant-based milks held just 8.9%.11 As nondairy milk continues to become more popular, it's important for dietitians to appreciate and counsel clients on how plant-based beverages can be a part of a balanced diet and consider how plant-based milks are produced.
Plant-milk beverages are manufactured by extracting plant material, such as soy, almonds, and rice, in water. The plant materials are homogenized and thermally treated to improve liquid suspension of the particles and increase shelf life, and they're made to resemble cow's milk in appearance.12 Commercial producers also have successfully introduced many varieties of plant-based and blended plant milks to the market. Silk, the leading soymilk producer, now offers a soy-free blended milk of pea protein, cashews, and almonds; Dream offers coconut-, almond-, and chia-blended milks.
Got Milk?
Despite the popularity of plant milks, there's an ongoing debate on whether they should be called "milk" at all since they're not derived from dairy animals. (See the Editor's Spot "Is Nut Milk a Misnomer?" in the June 2018 issue of Today's Dietitian.) The FDA defines milk as "the lacteal secretion … from the complete milking of one or more healthy cows … and shall not contain less than 8 1/4 percent milk solids."13
Needless to say, the dire dairy industry is among the most disgruntled about all of the processed plant beverages that have claimed the name "milk." In January 2017, the DAIRY PRIDE Act was introduced in Congress to enforce against misbranded milk alternatives, highlighting that the FDA is violating its own standards of identity for milk.14 In July, FDA Commissioner Scott Gottlieb, MD, announced that over the next year he intends to implement the change that nondairy beverages can't be identified as milk.15
Just as important, though, is the concern that many alternative milks (alt-milks) are nutritionally inferior to genuine dairy milk unless fortified. Plant-based beverages labeled as milk may not only confuse consumers but also pose a serious risk of nutritional deficiency, especially among infants and children.
To add irony to the mix, Elmhurst Dairy, founded in 1925, was once among the largest dairies on the East Coast, but two years ago, after experiencing continued losses in milk sales, the company made a drastic change and replaced its cows with nuts and grains. The company rebranded as Elmhurst Milked and defines itself as "a plant-based beverage company producing nondairy milk," identifying its transparency so that perhaps they may be immune if the DAIRY PRIDE Act is passed into law. Elmhurst beverages are called Milked Walnuts, Milked Oats, and so on, and are produced by an innovative and proprietary cold milling process developed by a culinary scientist. The patented process involves pressing nuts in a way that enables each component—the fats, proteins, fiber, vitamins, and minerals—to reengage with each other after separation to retain the full nutritional content and flavor of the nuts, without any gums, stabilizers, or emulsifiers. The disputed thickener carrageenan is now gone from most nondairy milks, and some brands also are gum-free.
Nutrient Considerations
The nutrient profile of cow's milk has been well established as the gold standard beverage with 8 g protein per 8-oz cup—about 60% of the recommended dietary allowance (RDA) for toddlers and 40% of the RDA for children.16 In addition, it's hard to beat the quality of cow's milk proteins—20% whey and 80% casein—both of which contain all nine essential amino acids.
According to the Protein Digestibility-Corrected Amino Acid Score, a method of measuring protein quality based on availability of essential amino acids as well as digestibility, cow's milk provides higher-quality protein than beef or soy.17 And, because of its high quality, cow's milk protein is used as a standard reference to evaluate the nutritive values of food proteins.18 Some of the proteins in cow's milk also have biological activities including enzymes, immunoglobulin, bactericides, hormones, mediators, and growth factors.19,20
And while plant-based milks can be consumed alternatively to cow's milk, they don't all have the same nutrition profile. In general, almond, rice, and coconut milks are woefully low in protein. Most commercial almond milk is made by roasting and grinding the nuts before blending them with a high volume of water and other ingredients. The solute is then filtered away with much of the almond's protein and fiber.
Conversely, whole cow's milk is energy dense due to its fat content that provides a rich source of cholesterol and saturated fatty acids important for the developing brain.21 Beyond age 2, switching to low-fat or nonfat milk is recommended, though newer research suggests that a high intake of dairy fat can be associated with a lower risk of developing central adiposity.22,23 Plant-based milks are low in saturated fats, but most of them contain calories equivalent to milk, derived mainly from sugar and other carbohydrates.
Bioavailability of Micronutrients
Moreover, calcium in cow's milk is highly bioavailable.20 Although many (but not all) plant milks are fortified with calcium and vitamin D, bioavailability of these micronutrients is uncertain, as nutrient content on a nutrition label doesn't guarantee equivalent nutritional value. Repeated research has shown that bioavailability of calcium varies significantly in fortified beverages.24 Very few manufacturers establish or optimize the bioavailability of the calcium they add to their products, yet consumers presume nutritional equivalence from label to consumption.
Both legumes and grains, the basis for many plant-based milks, contain high amounts of phytic acid, a compound that binds strongly to nutritionally essential minerals and trace elements, and that can impair bioavailability. Adequate absorption of minerals and trace elements is of special importance during periods of rapid growth and development.
All Plant Milks Are Not Created Equal
The many types, brands, flavors, and quality of plant milks can make it overwhelming to select something that tastes good and that contains adequate nutrition. But there are some good plant milks on the market. It's impossible to objectively critique every plant-based milk in this article; the comparison chart of alt-milks (see table on page 30) can be used as a nutrition primer.
Nutritionally, soymilk is the best alt-milk substitute for cow's milk in the human diet.18 Based on a research review published earlier this year that compared soy, almond, rice, and coconut milks with cow's milk, an 8-oz cup of soymilk boasts 7 to 12 g protein—one of the highest among the alt-milks. And, the calories in unsweetened soymilk compares to skim or 1% milk at 80 to 100 kcal per serving. But beyond protein and calories, it's important for the soymilk to be fortified with calcium, vitamin D, and vitamin B12 if following a vegan diet, to consider the bioavailability of the added nutrients, and/or that these nutrients are being obtained from other food sources. Plain soy can have a slightly "beany" taste, but this needs to be weighed against the nutrition attributes of sweetened and flavored varieties.
Almond, walnut, cashew, and other nut-based milks are good sources of polyunsaturated fats along with vitamins A and E. Some brands of nut milk are low in protein, as low as 1 g per cup. Environmentally speaking, it takes 1.1 gallons of water to grow one almond for consumption and 4 to 9 gallons to grow one walnut.25 California, which produces 99% of the almonds and walnuts in the United States, continues to endure record-setting drought conditions.
Rice milk is naturally sweet but low in protein. It's often consumed by those allergic to both soy and nuts. Arsenic has been a concern, with a few rice milks containing 70% in excess of the World Health Organization's set levels for drinking water.26
Most of the calories in unsweetened coconut milk are from lauric acid, a saturated fat that appears to be especially potent in its ability to increase HDL cholesterol. Though this effect may make coconut fat "less bad" than other saturated fats, most of the research on coconut oil has consisted of short-term studies.27 The medium-chain fatty acids (MCFA) in coconut milk are purported to support metabolism, thus causing a bit of a consumer craze. One good study showed that dieters given 18 to 24 g MCFAs daily for four months lost 3.5 lbs more than dieters given olive oil.28 However, consuming that many MCFA is equivalent to 26 to 34 cups per day of coconut milk. Favorable fat content aside, coconut milk is lacking in protein.
Hemp milk is a good source of omega-3 fats and magnesium but lacks calcium and vitamins D and B12 unless fortified. Magnesium, a cofactor for several enzyme systems that regulate diverse biochemical reactions, is required for energy production and membrane transport. Soy- and hemp-based beverages are good sources of magnesium.
Plant-based milks made with pea protein tend to have more protein and calcium than other alt-milks. In fact, pea protein is very high quality, close behind that of soymilk, and also contains all nine essential amino acids. Ripple plant milk, made with pea protein, claims to be more eco-friendly than its competitors and is "an easy way to lower your carbon footprint." But the company has been criticized for having its main ingredient, split yellow peas, shipped from France.
Given the increase in consumer demand for plant-based foods and environmental concerns, it may be just a matter of time before alt-milks dominate the market over cow's milk.
Practice Points for Alt-Milks
The American Academy of Pediatrics (AAP) recommends whole cow's milk until the age of 2 before considering plant-based milks.24 Cow's milk elimination from the diet during infancy and childhood should be recommended only after confirming a cow's milk protein allergy diagnosis. The AAP advises parents to read labels when choosing cow's milk alternatives for their families, since protein, micronutrient, and calorie content varies among different brands. A plant-milk substitution along with additional supplementation should be appropriate to minimize risk of nutritional inadequacy and poor growth.
The 2015–2020 Dietary Guidelines Advisory Committee found that several micronutrients essential for growth and development—vitamins A, D, E, and C, as well as folate, calcium, magnesium, fiber, and potassium—are being underconsumed relative to their requirements. For adolescent and premenopausal women, iron is also a shortfall nutrient. Of these nutrients, calcium and vitamin D (dairy milk is an excellent source of both), as well as fiber and potassium are classified as nutrients of public health concern because their underconsumption has been linked in the scientific literature to adverse health outcomes.29
Thus, it's important for RDs to consider that the nutrition needs of clients and patients are being met when plant-based beverages are substituted for cow's milk, as nonnutrient-dense alternatives can lead to nutrient deficiencies.12,30,31 When formulated into palatable and nutritionally adequate products, plant-based substitutes can offer a sustainable alternative to dairy products. Dietitians can share the following guidelines with clients:
- Read labels. The nutritional properties of alt-milks depend on the plant source, processing, and fortification.
- Shake plant-based beverages well, as some of the vitamins and minerals may settle to the bottom.
- Consider any additives in the ingredient list.
- Soymilk often is exchanged with cow's milk in cooking and baking with favorable results.
- Similar to cow's milk, plant-based milks have an estimated shelf life of seven to 10 days after opening.
- There's a growing interest in making plant milks (eg, pecan, pistachio, and sunflower) in the home kitchen, so advise clients on techniques and provide nutrient-dense recipes.
— KC Wright, MS, RDN, writes based on her research, clinical, and academic experiences. She advocates for quality food for health and sustainable food systems at www.wildberrycommunications.com.
References
1. US non-dairy milk market report. Mintel website. https://store.mintel.com/us-non-dairy-milk-market-report. Updated September 2017. Accessed June 12, 2018.
2. Americans are nuts for almond milk. Nielsen website. http://www.nielsen.com/us/en/insights/news/2016/americans-are-nuts-for-almond-milk.html. Updated March 31, 2016. Accessed June 15, 2018.
3. Plant-based food options are sprouting growth for retailers. Nielsen website. http://www.nielsen.com/us/en/insights/news/2018/plant-based-food-options-are-sprouting-growth-for-retailers.html. Updated June 13, 2018. Accessed June 25, 2018.
4. U.S. sales of dairy milk turn sour as non-dairy milk sales grow 9% in 2015. Mintel website. http://www.mintel.com/press-centre/food-and- drink/us-sales-of-dairy-milk-turn-sour-as-non-dairy-milk-sales-grow-9-in-2015. Updated April 20, 2016. Accessed June 25, 2018.
5. Allergic reactions to milk. Food Allergy Research & Education website. https://www.foodallergy.org/common-allergens/milk. Accessed June 15, 2018.
6. Gray CL, Goddard E, Karabus S, et al. Epidemiology of IgE-mediated food allergy. South Afr Med J. 2015;105(1):68-69.
7. Lactose intolerance. National Institute of Health, US National Library of Medicine, Genetics Home Reference website. https://ghr.nlm.nih.gov/condition/lactose-intolerance#statistics. Updated August 7, 2018.
8. Poore J, Nemecek T. Reducing food's environmental impacts through producers and consumers. Science. 2018;360(6392):987-992.
9. Why are Americans consuming less fluid milk? A look at generational difference in intake frequency. United States Department of Agriculture website. https://www.ers.usda.gov/webdocs/publications/45073/37650_err149_summary.pdf?v=41423. Updated May 2013. Accessed June 17, 2018.
10. Adolescent and school health; youth risk behavior surveillance system. Centers for Disease Control and Prevention website. https://www.cdc.gov/healthyyouth/data/yrbs/index.htm. Updated June 14, 2018. Accessed June 28, 2018.
11. Dairy and non-dairy milk: US. Mintel website. https://store.mintel.com/dairy-and-non-dairy-milk-us-april-2013. Updated April 2013. Accessed June 25, 2018.
12. Mäkinen OE, Wanhalinna V, Zannini E, Arendt EK. Foods for special dietary needs: non-dairy plant-based milk substitutes and fermented dairy-type products. Critl Rev Food Sci Nutr. 2016;56(3):339-349.
13. U.S. Food & Drug Administration. Code of Federal Regulations Title 21. Chapter I. Subchapter B. Food for human consumption. Section 133.3(a) Milk. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=133.3. Updated April 2017. Accessed June 15, 2018.
14. DAIRY PRIDE Act. Congress.gov website. https://www.congress.gov/bill/115th-congress/senate-bill/130/text. Updated January 12, 2017. Accessed June 18, 2018.
15. Gottlieb: FDA to crack down on labeling nondairy products as 'milk.' POLITICO website. https://www.politico.com/story/2018/07/17/almond-lactate-nondairy-milk-scott-gottlieb-725974. Updated July 17, 2018. Accessed July 23, 2018.
16. United States Department of Agriculture. National Nutrient Database for Standard Reference, Release 28. United States Department of Agriculture. National Nutrient Database for Standard Reference, Release 28. https://ndb.nal.usda.gov/. Updated May 17, 2016. Accessed June 19, 2018.
17. Schaafsma G. The protein digestibility-corrected amino acid score. J Nutr. 2000;130(7):1865S-1867S.
18. Vanga AK, Raghavan V. How well do plant based alternatives fare nutritionally compared to cow's milk? J Food Sci Technol. 2018;55(1):10-20.
19. Bos C, Gaudichon C, Tomé D. Nutritional and physiological criteria in the assessment of milk protein quality for humans. J Am Coll Nutr. 2000;19(2 Suppl):S191-S205.
20. Haug A, Høstmark AT, Harstad OM. Bovine milk in human nutrition — a review. Lipids Health Dis. 2007;6:25.
21. Kratz M, BaarsT, Guyent S. The relationship between high-fat dairy consumption and obesity, cardiovascular, and metabolic disease. Eur J Nutr. 2013;52(1):1-24.
22. Porto A, Drake R. Cow's milk alternatives: parents FAQs. HealthyChildren.org website. https://www.healthychildren.org/English/healthy-living/nutrition/Pages/Milk-Allergy-Foods-and-Ingredients-to-Avoid.aspx. Updated October 13, 2017. Accessed June 27, 2018.
23. Holmberg S, Thelin A. High dairy fat intake related to less central obesity: a male cohort study with 12 years' follow-up. Scand J Prim Health Care. 2013;31(2):89-94.
24. Heaney RP, Rafferty K, Dowell MS, Bierman J. Calcium fortification systems differ in bioavailability. J Am Diet Assoc. 2005;105(5):807-809.
25. Food facts: how much water does it take to produce…? Water Education Foundation website. https://www.watereducation.org/post/food-facts-how-much-water-does-it-take-produce. Updated 2018. Accessed June 25, 2018.
26. Shannon R, Rodriguez JM. Total arsenic in rice milk. Food Addit Contam Part B Surveill. 2014;7(1):54-56.
27. Willett WC. Ask the doctor: coconut oil and health. Harvard Health Publishing website. https://www.health.harvard.edu/staying-healthy/coconut-oil. Updated December 4, 2017. Accessed June 26, 2018.
28. St-Onge M, Bosarge A. Weight-loss diet that includes consumption of medium-chain triacylglycerol oil leads to a greater rate of weight and fat mass loss than does olive oil. Am J Clin Nutr. 2008;87(1):621-626.
29. US Department of Health & Human Services. Dietary Guidelines for Americans 2015–2020: Eighth Edition. http://health.gov/dietaryguidelines/2015/guidelines/. Published January 7, 2016.
30. Lee GJ, Birken CS, Parkin PC, et al. Consumption of non-cow's milk beverages and serum vitamin D levels in early childhood. CMAJ. 2014;186(17):1287-1293.
31. Lifschitz C, Szajewska H. Cow's milk allergy: evidence-based diagnosis and management for the practitioner. Eur J Pediatr. 2015;174(2):141-150.