New food products are being developed daily, and some definitely find their way to supermarket shelves. Over the last decade, plant-based milks have become increasingly popular as a substitution for cow’s milk.
Key nutrients provided by cow’s milk include protein, calcium and, if pasteurized, added vitamin D that assists the absorption of calcium. But, have you ever wondered whether these plant-based “milk” beverages offer the same nutrition as cow’s milk?
Marissa Madeira, a student in the University of Hawaii at Manoa’s Human Nutrition, Food and Animal Sciences Department, had the same question and presented her research last week at the university’s 28th College of Tropical Agriculture and Human Resources and College of Engineering Student Research Symposium.
Madeira went to 12 retail food stores in Honolulu and found 14 general types of plant-based “milk” products. These included five nut and nut blends (almond, cashew, coconut, hazelnut and various nut blends), seeds (flax and hemp), grains (oats, rice, and grain blends) and soy. There were more than 100 unique “milk” choices.
Question: Are all these plant-based “milk” products nutritionally similar to cow’s milk or to each other?
Answer: Based on the information provided on food labels, Madeira found that only properly fortified soy milk served as a reasonable source of the nutrients provided by milk. Although many of these plant-based “milk” products were lower in calories than 2 percent reduced-fat cow’s milk, they also were commonly much lower in key nutrients.
Q: What plant-based “milks” were lowest in calories?
A: Each milk type offered a range of calories, but overall, cashew, coconut and flax “milks” tended to have the lowest-calorie options.
Q: What nutrients were generally the lowest in plant-based “milks”?
A: Most of the plant-based options provided little protein — commonly well below half the protein in cow’s milk. However, a few types were better than others. For example, among the 52 different options for almond milk, most had little protein (equivalent to about 4 almonds per 8-ounce serving), but information on one almond “milk” option indicated that it was equivalent in protein to cow’s milk. Most soy “milks” provided protein amounts comparable to cow’s milk.
Q: Were calcium and vitamin D in adequate amounts?
A: Most of the plant-based “milks” had added calcium and vitamin D to make their levels similar to cow’s milk. However, the added calcium in these products tends to settle to the bottom of the carton, making it important to vigorously shake plant-based “milks” so that most of the calcium is not left in the bottom of the container.
Q: Do plant-based “milks” contain much sugar?
A: Cow’s milk has about 10 grams of naturally occurring sugar (lactose) per serving, but most of the almond milks have added sugar, with at least one brand containing almost twice as much sugar as cow’s milk. Rather high added-sugar options also were found in hemp, rice and soy milks.
Overall, the plant-based “milks” are generally low in protein but have added calcium and vitamin D at levels similar to milk. However, the body is likely to absorb a bit less of the calcium in these products compared with cow’s milk. Due to the nutritional non-equivalency of most plant “milks,” some have claimed that use of the term “milk” on these products is deceptive marketing.
Alan Titchenal, Ph.D., C.N.S., and Joannie Dobbs, Ph.D., C.N.S., are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii-Manoa. Dobbs also works with University Health Services.
