Complete protein

From Wikipedia, the free encyclopedia - View original article

 
Jump to: navigation, search
Main article: Protein (nutrient)

A complete protein (or whole protein) is a source of protein that contains an adequate proportion of all nine of the essential amino acids necessary for the dietary needs of humans or other animals.[1]

The following table lists the optimal profile of the essential amino acids, which comprises a complete protein, as recommended by the Institute of Medicine's Food and Nutrition Board:[2]

Essential Amino Acidmg/g of Protein
Tryptophan7
Threonine27
Isoleucine25
Leucine55
Lysine51
Methionine+Cystine25
Phenylalanine+Tyrosine47
Valine32
Histidine18

The following table shows the amino acid requirements of adults as recommended by the World Health Organization[3] calculated for a 62-kilogram adult, and the amino acid profile of 2530 kilocalories of baked potatoes (9 large baked potatoes),[4] which comprise a day's worth of calories for a 62-kilogram (136 lb) adult:[5]

Essential Amino AcidRequirement /day/62 kg adult9 large baked potatoes[citation needed]
mgmg
Tryptophan248565
Threonine9301830
Isoleucine12401830
Leucine24182691
Lysine18602933
Methionine+Cystine9301534
Phenylalanine+Tyrosine15503553
Valine16122682
Histidine620942

Nearly all foods contain all twenty amino acids in some quantity, and nearly all of them contain the essential amino acids in sufficient quantity. Proportions vary, however, and some foods are deficient in one or more of the essential amino acids. Though some vegetable sources of protein contain sufficient values of all essential amino acids, many are lower in one or more essential amino acids than animal sources, especially lysine, and to a lesser extent methionine and threonine.[6] However, as shown in the example of potatoes, above, nearly all foods provide sufficient amino acids to satisfy human requirements for sustaining life.

Consuming a mixture of plant-based protein sources can increase the biological value of food. For example, to obtain 25 grams of complete protein from canned pinto beans requires consuming 492 grams (423 kcal); however, only 364 g of pinto beans (391 kcal) are required if they are combined with 12 grams of Brazil nuts.[7] Complementary proteins need not be eaten at the same meal for your body to use them together. Studies now show that your body can combine complementary proteins that are eaten over the course of the day.[8][6]

Sources of complete protein[edit]

See also[edit]

Notes[edit]

  1. ^ a b c "Protein in diet". Medline Plus Medical Encyclopedia. U.S. National Library of Medicine and National Institute of Health. September 2, 2003. Retrieved 2006-10-28. 
  2. ^ [1][dead link] http://www.nutritiondata.com/help/analysis-help#protein-quality
  3. ^ World Health Organization, Protein and Amino Acid Requirements in Human Nutrition http://whqlibdoc.who.int/trs/WHO_TRS_935_eng.pdf, p. 245
  4. ^ National Nutrient Database for Standard Reference Release 26, Nutrient data for 11357, Potatoes, white, flesh and skin, baked http://ndb.nal.usda.gov/ndb/foods/show/3132?fg=&man=&lfacet=&count=&max=25&qlookup=potatoes&offset=&sort=&format=Full&reportfmt=other&rptfrm=&ndbno=&nutrient1=&nutrient2=&nutrient3=&subset=&totCount=&measureby=&_action_show=Apply+Changes&Qv=1&Q5995=9&Q5996=1.0&Q5997=1.0
  5. ^ Interactive DRI for Healthcare Professionals http://fnic.nal.usda.gov/fnic/interactiveDRI/dri_results.php
  6. ^ a b c Young VR, Pellett PL (1994). "Plant proteins in relation to human protein and amino acid nutrition" (PDF). American Journal of Clinical Nutrition 59 (5 Suppl): 1203S–1212S. PMID 8172124. 
  7. ^ Woolf, P. J.; Fu, L. L.; Basu, A. (2011). Haslam, Niall James, ed. "VProtein: Identifying Optimal Amino Acid Complements from Plant-Based Foods". PLoS ONE 6 (4): e18836. doi:10.1371/journal.pone.0018836. PMC 3081312. PMID 21526128.  edit
  8. ^ http://www.cdc.gov/nutrition/everyone/basics/protein.html
  9. ^ http://nutritiondata.self.com/facts/legumes-and-legume-products/4327/2
  10. ^ http://nutritiondata.self.com/facts/legumes-and-legume-products/4284/2
  11. ^ http://nutritiondata.self.com/facts/nut-and-seed-products/3164/2
  12. ^ http://nutritiondata.self.com/facts/nut-and-seed-products/3093/2
  13. ^ http://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2391/2
  14. ^ http://nutritiondata.self.com/facts/cereal-grains-and-pasta/10352/2
  15. ^ http://nutritiondata.self.com/facts/nut-and-seed-products/3136/2
  16. ^ http://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2704/2
  17. ^ http://nutritiondata.self.com/facts/vegetables-and-vegetable-products/2428/2
  18. ^ http://nutritiondata.self.com/facts/legumes-and-legume-products/4378/2
  19. ^ Campbell N, Reece J, Mitchell L (1999). Biology. Benjamin Cummings. ISBN 0-8053-6573-7. 
  20. ^ Livestrong.com webpage entitled NUTRITIONAL SOURCES OF ESSENTIAL AMINO ACIDS
  21. ^ "Tillery points out that a number of popular ethnic foods involve such a combination, so that in a single dish, one might hope to get the ten essential amino acids. Mexican corn and beans, Japanese rice and soybeans, and Cajun red beans and rice are examples of such fortuitous combinations."
  22. ^ "Quinoa: An emerging "new" crop with potential for CELSS (NASA Technical Paper 3422)" (PDF). NASA. November 2003. Retrieved 2006-10-28. [dead link]