Legume Sprouts: Friend or Foe

by Thomas E. Billings

Copyright (c) 1996 by Thomas E. Billings. This document may be distributed freely for non-commercial purposes provided 1) this copyright notice is included, 2) the document is distributed free of charge, with the sole exception that a photocopy charge, not to exceed ten cents (U.S.) per printed page may be charged by those distributing this paper. All commercial rights reserved; contact author for details (contact address given at end).

Question
The book, "Practically Macrobiotic," by Keith Mitchell, claims that many types of legumes (soybeans, chick peas, peas, lentils, alfalfa) should never be eaten raw, because they contain something called a "trypsin inhibitor" that can interfere with the digestion of protein, and the assimilation of the amino acid methionine. This is confusing, as many raw fooders regularly eat raw sprouted legumes. Please comment/explain.

Short answer
The named (raw) seeds do contain a number of anti-nutritive factors, which include enzyme inhibitors such as trypsin inhibitor. However, the levels of these anti-nutritive factors (with a few exceptions) decrease sharply when seeds are soaked and sprouted. Whether the small amount that remains after sprouting is of concern, is the point people disagree on. One anti-nutritive factor that actually increases is saponin in alfalfa, which peaks at 7-8 days, the time when most people eat them.

Long answer
A long answer is provided in the well-researched article: Warren Peary and William Peavy, "Natural Toxins in Sprouted Seeds: Separating Myth from Reality", in "Vegetarian Journal", vol 14, #4, July/August 1995, pgs. 17-20.

The above article specifies references for each of the seeds listed above. However, the coverage of saponin in the article is, in my opinion, too brief and not clear enough.

The above answers do not address important questions concerning sprouted legumes:

1) Taste: soybean sprouts and nearly all the large beans, taste incredibly bad when raw. The flavor is so bad you would not, and could not, eat them. Indeed, the usual reaction to trying to eat them is to spit them out. Any who doubt this are invited to prove it to themselves by soaking and sprouting such seeds for a day or two. Given that the taste when raw is so bad, that cooking is actually necessary (cooking destroys the enzyme inhibitors, and improves the flavor), the presence of anti-nutrient factors in raw soybeans and other large raw beans, is irrelevant.

2) Can you digest them? In general, not very well. Mung and adzuki beans are the easiest legumes to digest; the rest are more difficult. Flatulence is a serious problem with legumes. In the short run, flatulence is an inconvenience; in the long run it may promote disease (it is a mildly toxic gas, after all).

One way to reduce/eliminate the flatulence problem is to use mild spices to enhance/stimulate digestion. Specifically, ginger and turmeric enhance the digestion of protein, and cumin is anti-gas. Other mild spices can be used to stimulate digestion and reduce gas. Garlic (a not so mild spice) also stimulates digestion, and reduces gas.

3) How does your body react to eating sprouted legumes? Do you feel good after a meal of sprouted legumes? Do you have gas or bloating? Do you feel heavy or uncomfortable? The reaction of your body is the most important indicator. The reaction of your body is more relevant than research papers on anti- nutritive factors, or the opinions of others. Your body will tell you if the food is good or bad for you - if you only listen.

A closing remark. If you decide that large beans and/or legumes are not for you, there are many other grains, seeds, nuts that you can sprout. I would encourage you to experiment with sprouts of all kinds, including legumes, to determine the sprouts you like, and which sprouts agree with you.

P.S. sprouted mung beans are a regular part of my diet; other legumes I eat only rarely.

Author Contact:
Thomas E. Billings