Maybe Hans Christian Andersen was onto something when he put a lowly pea at the center of his fairy tale, “The Princess and the Pea. The food industry seems to be obsessed with peas, or at least their protein, which, extracted from yellow or green “field peas (the kind used to make dried split peas), is being used in everything from veggie burgers, energy bars, and popcorn to yogurt and ice cream. In some cases, pea protein is taking the place of soy protein isolates in processed foods.
Peas are the seeds from the pod fruit Pisum sativum, a member of the legume family. They are rich in protein, with one-half cup of cooked split peas providing 8 grams (by comparison, a large egg has 6 grams). And they’re less likely to cause allergies than other high-protein foods such as milk, eggs, nuts, and soy-a fact that some food companies are using in their marketing pitches.
According to a few animal and small human studies, pea protein may be able to help reduce cholesterol, lower blood pressure, improve satiety, and increase muscle.
Another plus: Peas are more eco-friendly to produce than animal sources of protein, requiring less fertilizer and water and yielding lower greenhouse gas emissions. But the environmental impact depends on what happens to the peas after harvest. As a 2010 paper in Food Research International found, it takes about the same amount of energy to produce a commercial pea-burger as it does a pork chop, calorie for calorie, because of all the processing, storing, and other factors involved.
How does pea protein compare with other protein sources? Meat, poultry, and dairy-as well as soy and quinoa-contain the complete set of essential amino acids needed for the body to synthesize protein. In contrast, peas are low or lacking in one or more of these amino acids and thus are not a “complete protein. Like most other legumes, they are high in the essential amino acid lysine, but low in the amino acid methionine. Still, contrary to common belief, you don’t need to combine complementary incomplete plant proteins in the same meal to make sure you are getting complete proteins. If you consume a variety of plant foods over the course of the day, you will likely get all essential amino acids and meet your protein needs.
Having pea protein as an ingredient doesn’t mean a food product is otherwise healthful or even high in protein. After all, food manufacturers are using it not necessarily for health reasons but more likely because it is a cheap source of protein. Some products are very high in sodium and added sugars, and they typically are highly processed, containing ingredients like carrageenan, methylcellulose, titanium dioxide, and sorbitol. Check the nutrition labels. Moreover, these products contain just the protein extract and are missing the other good things peas offer, including fiber, B vitamins, and minerals, as well as compounds such as saponins and catechins.
A healthy alternative to pea-protein processed foods-and one that’s cheaper and better for the environment-is to eat peas directly, either fresh (the immature green seeds, which are prepared like a vegetable) or split (green or yellow split peas are simply peeled and dried matured peas that are cooked like lentils). You can also add pea protein powder to smoothies or yogurt, though most people already get enough protein in their diets and don’t need more.