Is eating incomplete plant protein with quinoa beneficial for getting all essential amino acids?

Combining Incomplete Plant Proteins with Quinoa for Essential Amino Acids

Yes, eating incomplete plant proteins with quinoa is beneficial for obtaining all essential amino acids, as quinoa is one of the few plant foods containing all nine essential amino acids in adequate proportions, making it an excellent complementary protein to pair with other plant proteins that may be deficient in certain amino acids.

Understanding Protein Quality and Complementarity

Protein quality is determined by:

1. Essential amino acid composition: Foods containing all essential amino acids at levels that facilitate tissue growth and repair are considered complete proteins 1
2. Digestibility: How efficiently the body can absorb and utilize the protein

Most plant proteins are considered incomplete because they lack sufficient amounts of one or more essential amino acids:

• Grains are typically low in lysine
• Legumes are typically low in methionine 1
• Most plant proteins have lower digestibility (80-85%) compared to animal proteins (approximately 100%) 1

Why Quinoa Is Special

Quinoa stands out among plant foods for several reasons:

• Contains all nine essential amino acids in adequate proportions 2
• Particularly rich in lysine, which is typically limited in most grains 2
• Consists primarily of high-quality proteins:
  • 11S globulins (chenopodin) - 37% of total protein
  • 2S albumins - 35% of total protein 2
• Has protein content of approximately 17% 3
• Low in prolamins (0.5-7% of total protein), making it suitable for people with celiac disease 2

Benefits of Combining Quinoa with Other Plant Proteins

When incomplete plant proteins are combined with quinoa, the following benefits occur:

1. Complementary amino acid profiles: Quinoa can compensate for amino acid deficiencies in other plant proteins 1

   • Example: Combining corn (limited in lysine) with beans (limited in methionine) creates a high-quality protein combination 1

2. Improved protein quality: The combination can approach the biological value of animal proteins 4

   • A study on plant-based hamburgers found that formulations with 50% quinoa and 50% lupin achieved 92% protein digestibility and met requirements for lysine, threonine, and tryptophan 4

3. Nutritional adequacy: Ensures all essential amino acids are available for protein synthesis, tissue repair, and maintenance 1

Practical Applications

For optimal protein complementarity:

• Mix different plant protein sources throughout the day - contrary to previous beliefs, proteins don't need to be combined at the same meal 1
• Include quinoa as a staple grain in plant-based diets to improve overall amino acid profile
• Pair quinoa with legumes (beans, lentils, peas) for optimal amino acid balance
• Consider protein quantity - ensure adequate total protein intake (RDA is 0.8 g/kg body weight for adults) 1

Important Considerations

1. Protein adequacy is rarely an issue in developed countries, even for those following vegetarian or vegan diets 1

2. Plant protein combinations can meet requirements when consumed in sufficient quantities and variety 1

3. Environmental and health benefits of plant proteins should be considered alongside amino acid profiles 1

4. Protein quality metrics are evolving from older concepts like PDCAAS to newer measures like DIAAS that better account for digestibility 1

By strategically combining quinoa with other plant protein sources, you can effectively obtain all essential amino acids needed for optimal health while enjoying the additional nutritional benefits that diverse plant foods provide.