Soy Nutrition Institute

Evaluating Nutrition in Plant Milks

By Mark Messina, PhD, Executive Director, Soy Nutrition Institute

Which plant milk—soy, almond, cashew or coconut—is most nutritious? According to a recent  article in the New York Times, it’s none of the above. Instead, in what sounded like an advertisement for the dairy industry rather than a balanced overview of pros and cons of different plant milks, health writer Roni Caryn Rabin suggested that all fall short compared to cow’s milk.  

To build her case for cow’s milk, Rabin made some dubious as well as conflicting observations. For example, she touted as one of the benefits of cow’s milk the fact that it is fortified with vitamin D and vitamin A. But, in addressing nutrient content of soymilk, she pointed out that it is often “artificially fortified” with calcium. It begs the question: how are the nutrients added to plant milks any more “artificial” than those added to cow’s milk? And if, as Rabin contends, added nutrients may not be as bioavailable as naturally-occurring ones, why highlight the ones added to cow’s milk at all?

In fact, almost all plant milks contain added calcium and it is well established that the calcium in fortified soymilk is absorbed just as well as the calcium in cow’s milk.1 While Rabin linked to one brand of soymilk that isn’t fortified, it’s the exception rather than the rule.  The overwhelming majority of soymilk that is sold in the U.S. is fortified with calcium.

She also pointed to the fat content of soymilk as a disadvantage. But since that fat is predominately polyunsaturated fat and includes both of the essential fatty acids, linoleic acid and alpha-linolenic acid, its fat content is a benefit.  Replacing saturated fat from dairy in the diet with polyunsaturated fat is associated with lower risk for heart disease—which means that replacing cow’s milk with soymilk is a healthy choice.2  Doing so may be especially relevant for young children who need to consume milks that provide those essential fats.  

Finally, the author warns about additives in plant-based beverages that have been tied to allergic reactions. In particular, she notes that the FDA warns against feeding foods containing xanthan gum to infants. That may be true, but it’s also irrelevant to any discussion of plant milks. The only milks that are suitable for infants are breast milk or commercial infant formula. Infants are not supposed to be drinking any commercial plant milk. They aren’t supposed to be drinking cow’s milk either.   Furthermore, with respect to allergies, allergy to cow’s milk protein is many times more prevalent that allergy to soy protein.3,4

It’s true that plant milks vary in their nutrient content and that many are very low in protein. But most are excellent sources of calcium and vitamin D.  Furthermore, not only is soymilk an excellent source of these two nutrients it has the added advantages of providing healthy fat and similar amounts of high-quality protein as found in cow’s milk.5

  1. Zhao Y, Martin BR, and Weaver CM. Calcium bioavailability of calcium carbonate fortified soymilk is equivalent to cow's milk in young women. J Nutr 2005;135:2379-82.
  2. Chen M, Li Y, Sun Q, Pan A, Manson JE, Rexrode KM, Willett WC, Rimm EB, and Hu FB. Dairy fat and risk of cardiovascular disease in 3 cohorts of US adults. Am J Clin Nutr 2016;104:1209-1217.
  3. Vierk KA, Koehler KM, Fein SB, and Street DA. Prevalence of self-reported food allergy in American adults and use of food labels. J Allergy Clin Immunol 2007;119:1504-10.
  4. Gupta RS, Springston EE, Warrier MR, Smith B, Kumar R, Pongracic J, and Holl JL. The prevalence, severity, and distribution of childhood food allergy in the United States. Pediatrics 2011;128:e9-17.
  5. Hughes GJ, Ryan DJ, Mukherjea R, and Schasteen CS. Protein digestibility-corrected amino acid scores (PDCAAS) for soy protein isolates and concentrate: Criteria for evaluation. J Agric Food Chem 2011;59:12707-12.

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