Another myth: vegans need to combine beans and grains to create “complete proteins”

July 18, 2015 at 8:20 pm (Uncategorized)

My mom recently asked me if wild rice combines with beans to form a “complete protein,” as brown rice does. I thought I’d post my answer to her here, as the myth about complete proteins is pretty widespread.

The “incomplete protein” myth was first popularized by Frances Moore Lappé in her 1971 book, Diet for a Small Planet. The main concern is that, as a general rule, legumes are lower in the essential amino acid methionine while most other plants foods (including grains) are lower in the essential amino acid lysine. So to get a “complete protein” you have to eat grains and beans together.

An aside: I’m not sure how “most other plant foods” became “grains.” Maybe it’s because most people think beans and grains are the only plant foods that have much protein? They seem to not realize that nuts and vegetables can also provide non-negligible amounts of protein.

But going back to the complete protein myth. Today, most vegetarians (at least) know that your body can store the essential amino acids and so you don’t have to actually eat grains and beans together at every meal. But many vegetarians still seem to believe that you have to eat both grains and beans in order to get all the essential amino acids. But that is also a myth. What is true: Most vegans will need to eat beans and other high-lysine foods regularly in order to meet the RDA for the essential amino acid lysine. Grains are not necessary. A vegan that is getting enough protein should have no problem getting enough methionine. Read the rest of this entry »

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