Overall Nutrient Richness
Perhaps the most striking health benefit provided by quinoa is its overall nutrient richness. When the nutrient composition of this food is analyzed in depth, the results are unusual and striking. Quinoa can be eaten in the same way as a grain, or ground into flour like is so commonly done with grains.
Most grains are considered to be inadequate as total protein sources because they lack adequate amounts of the amino acids lysine and isoleucine. The relatively low level of both lysine and isoleucine in the protein of grains is what causes these amino acids to be considered as the limiting amino acids (LAAs) in grains. In other words, these LAAs prevent grains from serving as complete protein sources in our diet. By contrast, quinoa has significantly greater amounts of both lysine and isoleucine (especially lysine), and these greater amounts of lysine and isoleucine allow the protein in quinoa to serve as a complete protein source.
In terms of fat content, it only takes 63 calories' worth of quinoa to provide 1 gram of fat, quinoa is typically considered to be a valuable source of certain health-supportive fats. About 25% of quinoa's fatty acids come in the form of oleic acid, a heart-healthy monounsaturated fat, and about 8% come in the form of alpha-linolenic acid or ALA—the omega-3 fatty acid most commonly found in plants and associated with decreased risk of inflammation-related disease.
Quinoa contains significant amounts of certain tocopherols (vitamin E family members) largely absent from most grains. For example, one cup of quinoa provides 2.2 milligrams of gamma-tocopherol—a form of vitamin E that has been more closely associated with certain anti-inflammatory benefits in health research. Quinoa is also a good source of RDA nutrients like folate, copper, and phosphorus.
Yet another key mineral—calcium—is especially concentrated in quinoa in comparison to grains. On an ounce-for-ounce basis, quinoa provides over twice the amount of calcium as is found in whole wheat.
Quinoa is an equally impressive food in terms of its overall phytonutrient benefits. In many Central and South American countries, the leaves of the quinoa plant are valued for their betacyanin pigments, which provide some of their bright reddish shades. But even the seeds themselves can be phytonutrient-rich and can provide significant amounts of antioxidants like ferulic, coumaric, hydroxybenzoic, and vanillic acid.
The antioxidant flavonoids quercetin and kaempferol are also especially plentiful in quinoa. In fact, the concentration of these two flavonoids in quinoa can sometimes be greater than their concentration of high-flavonoid berries like cranberry.
Considered in combination, these diverse nutrient benefits of quinoa give it uniqueness among grain-related foods. This high overall level of nourishment provided by quinoa may qualify as its greatest health benefit.
Quinoa is a perfect food to include on a gluten-free diet, since it not only lacks gluten but doesn't even belong to the same plant family as wheat, oats, barley, or rye. Some studies also show quinoa flour to have higher-than-expected digestibility.