Legumes – optimal intake

Introduction

This is a follow-on from the previous two notes, as legumes featured heavily in last week’s life expectancy note (Ref 1) and were an important food for minimum intake in the Global Burden of Disease study (2019), which we reviewed the week before that (Ref 2).

The term Fabaceae (also known as the pea family and/or Leguminosae) features approximately 670 genera and 20,000 species of trees, shrubs, vines and herbs. Members of the family are generally characterised by their leaves and the production of fruits known as legumes. Common names of legumes include alfalfa, green bean, carob, chickpea, liquorice, lentil, pea, and soybean (Ref 3).

Legumes can be viewed as an ancestral food. An academic review of legumes proposed that their origin dates back millions of years. Asia and especially sub-Saharan Africa are the natural growing terrains for legumes. They have historically been an important food in these regions providing relatively cheap nutrients for large and growing populations. They are now being seen as a health food by populations for whom they are not indigenous, as the drive towards plant based diets continues (Ref 4).

Increasingly, as animal foods have been demonised, plant foods have been recommended to replace these. Legumes have become a key food group being promoted, while red meat and dairy have been attacked. We’ll take a look this week at optimal intakes of legumes – as recommended by seminal nutritional studies. We’ll examine the robustness of these recommendations and compare the nutritional value of legumes with the animal foods that they are desired to replace.