Healthy Decisions for the Love of Health

Anti-Nutrients in Whole Grains, Nuts  and Seeds - Reasons For Pre-soaking

 Whole Grains

What are whole grains?

Grains are the seeds of plants. Whole grains contain all parts of the grain, including the bran, endosperm and germ.

  • Bran. Forming the outer layer of the seed, the bran is a rich source of niacin, thiamin, riboflavin, magnesium, phosphorus, iron and zinc. The bran also contains the majority of the seed's fiber.
  • Germ. A concentrated source of niacin, thiamin, riboflavin, vitamin E, magnesium, phosphorus, iron and zinc. The germ also contains protein and fat.
  • Endosperm. Also called the kernel, the endosperm makes up the bulk of the seed. It contains most of the grain's protein and carbohydrate and has small amounts of vitamins and minerals.

What are milled, processed and refined grains?

  • Unlike whole grains that contain at least part of their bran and germ layers, milled, processed and refined grains have both the bran and germ removed during processing; therefore all of the nutrients in these layers are also removed.
  • They are often “enriched” which means nutrients that were lost during food processing are added back. For example, B vitamins, lost when wheat is refined, are added back to white flour during processing. However, even after enrichment, milled grains do not have as many nutrients as whole grains, and they do not provide as much fiber, if any.

Grains as a ---

Carbohyrate source
Whole grains are made of a rich starch store (the endosperm) comprising from 60- 80% of the seed (depending on the species and variety), the embryo plant (the germ) rich in protein and fats and vitamins and comprising only about 3% of the seed, and the seed coat, the bran, which is where most of the B vitamins (and many of the minerals) are. At 80% carbohydrate, seeds are, like tubers, an excellent fuel for daily activity. And whole seeds contain the B1 vitamin necessary for carbohydrate metabolism. Grains are relatively 'slow burners', so they don't push up your blood sugar levels and then suddenly drop them - they tend to keep blood sugars relatively stable.

Grains as a ---

Protein source
Protein builds growing bodies, and protein is made up in turn of 'building blocks' called amino acids. Grains are low in the amino acid 'lysine', which makes their protein content less useful than it would otherwise have been. Wheat has about 8-15% protein, depending on the variety (ancient wheats had a higher protein content), rice has a low content, at 7%. So grains in general are perhaps best regarded primarily as an energy and vitamin and mineral source.

Grains as a ---

Fibre source
Whole grains have a lot of 'woody' (for want of a better description) fibre in their seed coat which help regulates bowel activity. What is less well known is that many also contain soluble fibre, which also has positive health benefits. The soluble and insoluble fiber in seeds is known to be helpful in preventing constipation and diseases of the digestive tract such as diverticulitis. It is also suspected that fiber may have a protective effect against colon cancer. Oats contain quite high amounts of soluble fiber, as does barley, and to a lesser extent, wheat.

Grains as a ---

Source of fats, including essential fatty acids
The oils in oily seeds are an excellent energy source, and when eaten as part of the whole seed are slowly parcelled out into the blood stream over a period of hours. While oily seeds are a concentrated source of calories, like any calory containing (or convertable) food, their calories are only stored as fat when we eat more calories than we need for energy. Otherwise, the oils and carbohydrate are burnt in the furnace of active life.


 In the past, various traditional methods people used to improve the quality and safety of food included drying, sprouting, culturing, sour leavening, fermentation, and soaking. Today, for many, the concept of pre-soaking plant foods such as whole grains, legumes, raw nuts and seeds is unfamiliar, as are the reasons for doing so. These whole foods, packed with nutritional goodness, also contain anti-nutrients, such as enzyme inhibitors, which can strain digestion, reduce and even inhibit the absorption of certain essential minerals (for example, calcium, iron, zinc, magnesium).

Grains and Seeds contain 'antinutrients' - substances such as saponins, tannins, 'protein splitting enzymes' inhibitors, and phytates. These compounds reduce the body's ability to access the nutrients in seeds. The type, and amount of anti-nutrient varies both with the species of plant, and with the local variety of the species (common beans, Phaseolus vulgaris, for example, have a wide range of  phytic acid and tannin concentrations - with white seeded beans having least tannins-depending on the variety). Some have several different anti-nutrients, some have few, some have relatively a 'lot' of any one anti-nutrient, some have very little.

Most, but not all, antinutrients are destroyed or reduced by soaking, sprouting, leaching and cooking. Soaking and leaching are necessary to reduce some antinutrients, particulalry in some varieties of bean and other legumes. Soaking and sprouting seeds also reduces phytates. Soybeans, for example, contain a 'tryptophane inhibiter' that interferes with the absorbtion of the amino acid 'tryptophane'. The inhibitor can be neutralized both by cooking and by sprouting (the sprouted root must be 3 to 4 inches long for this to be largely complete).

A very low percentage of the starches in some seeds 'resist' being digested ( up to 7%  for wheat, and oats and 20% for baked beans) These undigested starches are fermented by the microflora of the colon, producing variable quantities of gas.

What does pre-soaking do? It transforms food in beneficial ways by starting the sprouting process, which increases some of the nutrients, neutralizes enzyme inhibitors (such as phytic acid), softens hard fibres, making food not only digest and absorb better, but taste better too!   Soaking nuts and seeds stimulates the process of germination, not only increasing the vitamin C content, but also increasing Vitamin B content and carotenes (pre-vitamin A).  Most importantly, this soaking neutralizes phytic acid, a substance present in the bran of all grains and seeds that inhibits absorption of calcium, magnesium, iron, copper and zinc.  Soaking also neutralizes enzyme inhibitors present in all seeds.  These inhibitors can neutralize our own precious enzymes in the digestive tract.  Complex sugars responsible for intestinal gas are broken down from soaking and a portion of the starch in the seed is transformed into simpler sugars.  Aflotoxins (potent carcinogens found in grains) are inactivated.  Finally, numerous enzymes that help digestion are produced during the germination process.


How to presoak? Here are some basic soaking guide lines: Whole grains: overnight or 8-12 hours. Discard soak water, then add less water (about half) for cooking. Legumes: overnight or 12 hours (lentils, whole dried peas less; garbanzo, soy longer). Change water before cooking. Some of the enzymes and trisaccharides, which can cause gas are released during soaking. Nuts and seeds: overnight. Dry and either eat raw or roast on low heat. Fats and protein also become more digestible.

This really doesn’t take more time; in fact, you will save time as food cooks faster when presoaked. A little planning and habit is all that is needed: place food for the evening or next day in water in the pot you will then use for cooking. Simple!

 Copyright © 2005 HealthSmart Nutrition. All rights reserved.
Revised: June 23, 2007


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