Hola Inma,

You are correct that there is a secondary or tertiary meaning of the word "pulse" in English which means "the edible seeds of various leguminous plants, for example chickpeas, lentils, and beans." Thanks for making me look it up. You learn something new every day!

However, the first translation that I see for "la legumbre" in spanishdict.com is "legume". 

As a native English speaker I can tell you that the translation of "Las legumbres aportan proteínas y hierro a nuestro cuerpo" would be clearer as "Legumes provide proteins and iron for our bodies."

I learned my English in the US. Maybe the use of "pulse" in the sense of "leguminous seeds" is more commonly used in other English-speaking countries like the UK. Just guessing. "Divided by a common language."

Saludos,

Tom

I’ve definitely heard “pulses” in the US, but usually more in texts that are giving diet advice, like on a medical website. Legumes is more common in conversation, although I also looked it up to double check, and technically the pulses are the seed part we eat (beans, lentils) and legumes refers to all the rest of the plant itself.