Quinoa is not a grain. It is the seed of a plant in the amaranth family, a relative of spinach, which is why it is called a pseudocereal. Cooks use it like rice or couscous, and it contains no gluten.
The seed is wrapped in a bitter coat of compounds called saponins, and the bitterness deters birds. A 2017 genome study found the regulator gene likely to control saponin production, and a mutation in it in “sweet” quinoa strains. Washing and polishing reduce the saponins, and most commercial quinoa has had the coat removed.
Quinoa protein contains all nine essential amino acids, so it counts as a complete protein, and dry quinoa has about 14.1 g of protein per 100 g. How well it scores depends on the yardstick and the seed sample, and the protein question is answered in the FAQ below. Trials in people are few, small and short, and they are what the studies below describe.
Health benefits of quinoa
The top findings from 19 studies, strongest evidence first
What the stars mean
- Strong. Several randomized trials, pooled in a meta-analysis, point the same way, or regulators (FDA or EFSA) have approved the claim.
- Moderate. Good randomized trials support it, but there are fewer of them, or their results vary.
- Limited. Small, short or single trials, or mixed results. Promising, but it needs confirmation.
Population and lab studies get no stars: they show a link or a mechanism, not proof.
How we rate evidence →- ★★A little lower LDL and triglyceridesAcross 5 small trials (206 people), adding quinoa seeds lowered LDL by 3.08 mg/dL and triglycerides by 7.20 mg/dL. Quinoa biscuits lowered LDL by 0.25 mmol/L more than wheat biscuits, but quinoa bread did not beat wheat bread.
- ★★Unclear effect on body weightA pooled analysis of 7 trials found weight 0.54 kg lower than on placebo, which was not significant. Another pooled analysis of 5 trials found weight fell 1.26 kg.
- ★★No clear edge over rice or bulgurQuinoa at 40 g a day for 4 weeks did not change cholesterol, blood sugar or body measures more than rice or bulgur. This trial had 148 adults with overweight or obesity, and some changes showed up only within subgroups.
- ★Better blood sugar control in small trialsIn people with impaired glucose tolerance, a quinoa diet for a year cut the rate of developing diabetes to 7.8%, against 20.3% in controls. In early type 2 diabetes, blood sugar after a meal fell by 4.57 mmol/L, against 2.2 mmol/L on a regular diet.
- ★Lower fatty liver score in a small trialIn 46 people with fatty liver, swapping grains for quinoa at lunch for 12 weeks lowered a fatty liver score, LDL cholesterol and insulin resistance.
All 19 studies, strongest evidence first
Eating 40 g a day of quinoa for 4 weeks did not change cholesterol, blood sugar or body measures differently from rice or bulgur
Randomized trial in 148 adults aged 25 to 45 with overweight or obesity, who ate 40 g a day of quinoa, buckwheat, rice or bulgur. Fat mass fell within the quinoa group and fasting glucose fell only in men. Total cholesterol fell in men but rose in women on quinoa. These came from subgroup analyses, not group comparisons.
Adding quinoa seeds to the diet in trials lowered LDL cholesterol by 3.08 mg/dL and triglycerides by 7.20 mg/dL
Meta-analysis of 5 randomized trials (206 people) of quinoa seed supplementation. Total cholesterol fell 6.86 mg/dL, body weight 1.26 kg and waist size 1.15 cm, while the other markers did not change significantly. These are small drops pooled from small trials.
Quinoa did not significantly change body weight or BMI in a meta-analysis of 7 trials, and its blood sugar effect was a curve, not a clear drop
Meta-analysis of 7 randomized trials (258 adults) that gave 15 to 50 g of quinoa a day for 28 to 180 days. Weight was 0.54 kg lower than on placebo, which was not significant. Fasting blood sugar showed a nonlinear dose-response, with the slope changing at about 25 g a day. The authors call for more studies. The weight result differs from the meta-analysis above.
Replacing about half of the daily staple food with 100 g of quinoa for a year lowered 2-hour blood sugar, fasting insulin and insulin resistance more than a mix of whole grains did
Randomized trial in 207 people with impaired glucose tolerance, assigned to quinoa, a multiple whole grain mix (100 g a day) or a control diet. HbA1c improved on both grain diets compared with control, and fewer people on quinoa developed diabetes. The abstract gives no numbers, and the study shares authors and a Guangzhou health center with the trial below.
In people with impaired glucose tolerance, a quinoa-based diet for a year cut the rate of developing diabetes to 7.8%, against 20.3% in the control group
Randomized trial in 138 people at one Guangzhou health center. After 1 year the quinoa group had lower 2-hour blood sugar, HbA1c, insulin resistance and BMI than controls, and higher HDL cholesterol. The abstract does not say how much quinoa people ate.
In early type 2 diabetes, a quinoa diet lowered blood sugar after a meal by 4.57 mmol/L, against 2.2 mmol/L on a regular diet
Randomized trial in 60 people with early-stage type 2 diabetes. HbA1c fell 0.86 versus 0.28 and time in range rose, and more people on quinoa cut or stopped diabetes medicine (28.6% versus 7.1%). It was a small trial, and the abstract does not give the amount of quinoa.
Replacing grains with quinoa at lunch for 12 weeks lowered a fatty liver score, LDL cholesterol and insulin resistance in people with fatty liver
Randomized trial in 46 people with non-alcoholic fatty liver disease. Weight and waist size also fell, but liver enzymes, scan stiffness, fasting glucose, total cholesterol, HDL and inflammation markers did not change significantly. The results held after adjusting for weight loss.
Daily quinoa biscuits for 4 weeks lowered LDL cholesterol by 0.25 mmol/L more than wheat biscuits in older adults
Double-blind crossover trial in 40 adults aged 50 to 75 who ate 15 g biscuits made with quinoa flour or wheat flour. Total cholesterol fell 0.30 mmol/L more and weight 0.61 kg more on quinoa. Triglycerides, HDL and CRP did not differ.
20 g of quinoa flour a day in bread for 4 weeks did not lower LDL cholesterol or blood sugar more than plain wheat bread, though continuous glucose readings were lower
Crossover trial in 37 overweight men aged 35 to 70. LDL and blood glucose fell in both groups, with no difference between them. The total area under the blood glucose curve over the last 4 days was lower on quinoa than on wheat (p = 0.039).
25 g a day of quinoa flakes for 4 weeks lowered total cholesterol from 191 to 181 mg/dL and LDL from 129 to 121 mg/dL, while corn flakes did not
Double-blind trial in 35 women with excess weight who ate quinoa flakes or corn flakes. Triglycerides fell in both groups. The abstract reports the changes within each group and does not give a direct comparison.
Processed quinoa for 28 days lowered HbA1c and raised fullness ratings in people with prediabetes, but not fasting blood sugar
Randomized, double-blind trial in 30 people with prediabetes, comparing a processed quinoa product with a maltodextrin placebo. BMI also fell, and 29 people finished. It was a small, short trial and the article is in Spanish.
Nine older adults with prediabetes who swapped starchy foods for quinoa for 4 weeks lost 1.6 kg and had lower blood sugar after meals
Pilot study of 9 people aged 65 or older, using glucose sensors, with 4 weeks of regular diet followed by 4 weeks of quinoa diet in that fixed order. Waist size fell 1.5 cm and BMI 0.6 kg/m². The fixed order means time or other diet changes may explain part of the result.
Cooked quinoa raised blood sugar less than white bread after a meal in healthy young adults
Randomized crossover pilot study. Each person ate cooked quinoa or white bread with 25 g or 35 g of available carbohydrate on separate days, and blood glucose was measured for 120 minutes. Quinoa gave a lower rise at both doses, and appetite ratings also improved. A single-meal test, not a diet trial.
Replacing 20 g of refined wheat flour with quinoa flour for 4 weeks did not change the gut bacteria
Randomized crossover trial in 28 men who ate a quinoa-enriched or plain wheat roll daily. Stool tests showed no change in bacterial groups or diversity after either roll. The authors say higher amounts or longer exposure might behave differently.
Celiac patients who ate 50 g of quinoa a day for 6 weeks tolerated it well, and their condition did not get worse
Uncontrolled trial in 19 celiac patients already on a gluten-free diet, with gut biopsies in 10. The villus height to crypt depth ratio rose from 2.8 to 3, and total cholesterol fell from 4.6 to 4.3 mmol/L. The authors call for longer studies.
2 of 15 quinoa varieties triggered immune responses similar to gliadin in cells and gut biopsies from celiac patients
Lab study of 15 quinoa varieties. Only 4 had measurable amounts of celiac-toxic epitopes, and all were below the legal limit for gluten-free food. The 2 varieties named Ayacuchana and Pasankalla stimulated immune cells and biopsy cultures about as much as gliadin did. This was not a feeding trial.
Quinoa increased the permeability of the gut barrier in intestinal cells and in rats
Lab study using a human intestinal cell line and Brown Norway rats, with cholera toxin and capsaicin as comparison. The authors note that quinoa is rich in saponins, which are known to affect the gut barrier, and that quinoa has been proposed as an early food for infants. Its meaning for people eating cooked quinoa is unknown.
Crude saponins from quinoa husks caused slight intestinal damage in female rats at the highest dose
Lab study of 90 days in rats given 0, 5, 50 or 500 mg per kg of body weight a day, with toxic effects that differed by sex. Rats given saponins also weighed less and had lower blood sugar. The authors put the no-observed-adverse-effect level under 50 mg per kg a day. It used a husk extract, not rinsed quinoa seeds.
Quinoa in the diet of obese diabetic mice lowered cholesterol and fatty liver but raised blood insulin
Lab study in db/db mice fed a quinoa diet, compared with lean and obese controls. Quinoa brought total cholesterol, LDL and liver fat down to near lean levels, but it did not protect against other features of the model. The authors say doses closer to human diets are needed.
Who should be careful with quinoa
Most people can eat quinoa freely. Take a little care if one of these applies:
- Celiac disease. Quinoa has no gluten, but gluten from nearby wheat, rye or barley can get into it during growing, transport or packing. The FDA lets a grain be labeled gluten-free only below 20 parts per million, so buy labeled quinoa, and ask your care team before adding it. The 19 celiac patients in one small trial tolerated it, though 2 of 15 varieties triggered immune cells in the lab.
- Allergy. Quinoa allergy is rare, but case reports describe anaphylaxis, including a 2009 report described as the first in France. Stop eating it and get medical advice if it causes hives, swelling or breathing trouble.
- Saponins. This is a small concern. The bitter coat is removed in processing and by rinsing, and the rat study above used a husk extract, not cooked seeds. No trial in people has tested it.
How to choose, store and eat quinoa
- Whole seeds: Oregon State University Extension simmers 1 cup of quinoa in 2 cups of water for 12 minutes, which makes about 3 cups. Rinse it in a fine-mesh strainer first if the package does not say pre-rinsed.
- Flakes and flour: trials used 25 g a day of quinoa flakes in 35 women, 15 g biscuits in 40 older adults, and 20 g of flour in bread in 37 men.
- As a swap: in trials quinoa replaced other staples, such as grains at lunch for 12 weeks in 46 people with fatty liver, and cooked quinoa gave a lower blood sugar rise than white bread after a single meal.
Quinoa seeds range from white to red and black, and the package should say whether they are pre-rinsed. Refrigerate cooked leftovers within 2 hours. Pesticide residues are a small concern: in a Canadian Food Inspection Agency survey of 418 grain products from 2011 to 2012, 382 had no detectable residue, and the one sample over the legal limit was quinoa, which the agency did not expect to pose an unacceptable health concern.
Sources
- Questions and answers on the gluten-free food labeling final rule. U.S. Food and Drug Administration.
- Zevallos VF, Ellis HJ, Suligoj T, Herencia LI, Ciclitira PJ. Variable activation of immune response by quinoa (Chenopodium quinoa Willd.) prolamins in celiac disease. Am J Clin Nutr. 2012.
- Zevallos VF, Herencia LI, Chang F, Donnelly S, Ellis HJ, Ciclitira PJ. Gastrointestinal effects of eating quinoa (Chenopodium quinoa Willd.) in celiac patients. Am J Gastroenterol. 2014.
- Astier C, Moneret-Vautrin DA, Puillandre E, Bihain BE. First case report of anaphylaxis to quinoa, a novel food in France. Allergy. 2009.
- Hong J, Convers K, Reeves N, Temprano J. Anaphylaxis to quinoa. Ann Allergy Asthma Immunol. 2013.
- Suárez-Estrella D, Torri L, Pagani MA, Marti A. Quinoa bitterness: causes and solutions for improving product acceptability. J Sci Food Agric. 2018.
- Zhang R, Zhai Q, Yu Y, et al. Safety assessment of crude saponins from Chenopodium quinoa Willd. husks: 90-day oral toxicity and gut microbiota & metabonomics study in rats. Food Chem. 2022.
- Stovetop quinoa. Oregon State University Extension Service.
- 2011-2012 pesticides in finished grains and grain products. Canadian Food Inspection Agency.
History of quinoa
Quinoa was first domesticated in the Andes, around Lake Titicaca in what is now Bolivia and Peru. Estimates of its age vary: one review says more than 7,000 years ago, while an encyclopedia summary dates early use as livestock feed to 5,200 to 7,000 years ago and use as human food to 3,000 to 4,000 years ago.
Quinoa carries two full sets of chromosomes from two ancestor species, a condition called allotetraploid. In 2017 researchers published its chromosome-scale genome, and they found a mutation in a saponin regulator gene in sweet strains.
Spanish rule did quinoa no favors. After the conquest it was rejected as “Indian food,” and it was neglected for centuries before its potential was rediscovered in the second half of the 20th century.
Then it went global. The number of countries growing quinoa rose from 8 in 1980 to 40 in 2010 and 75 in 2014, and the San Luis Valley of Colorado has grown it since 1983. NASA also chose quinoa as an experimental crop for long space missions.
In 2013 the United Nations declared the International Year of Quinoa. It was meant to honor the ancestral practices of Andean peoples, who preserved the crop, and to draw attention to its role in food security, nutrition and poverty eradication.
The boom raised hard questions. Quinoa prices roughly tripled between 2006 and 2013, and many people worried that Andean families could no longer afford their own staple. A study of ten years of Peruvian household surveys found that welfare rose as quinoa prices rose, including for households that did not grow it, though producers gained faster only at the peak of the boom. Bolivia’s southern highlands drew a separate argument: a 2011 review warned of soil damage and falling home consumption, and a 2012 reply said its data did not show a drop in yield and its consumption claim was ill-founded. Prices fell sharply from 2015.
Sources
- Quinoa. Wikipedia.
- International Year of Quinoa. Wikipedia.
- Bazile D, Jacobsen SE, Verniau A. The global expansion of quinoa: trends and limits. Front Plant Sci. 2016.
- Jarvis DE, Ho YS, Lightfoot DJ, et al. The genome of Chenopodium quinoa. Nature. 2017.
- Bellemare MF, Fajardo-Gonzalez J, Gitter SR. Foods and fads: the welfare impacts of rising quinoa prices in Peru. World Dev. 2018.
- Jacobsen SE. The situation for quinoa and its production in southern Bolivia: from economic success to environmental disaster. J Agron Crop Sci. 2011.
- Winkel T, Bertero HD, Bommel P, et al. The sustainability of quinoa production in southern Bolivia: from misrepresentations to questionable solutions. Comments on Jacobsen (2011). J Agron Crop Sci. 2012.
Frequently asked questions about quinoa
Is quinoa good for you?
For most people, yes. A ¼ cup of dry quinoa (43 g) has 156 calories, 6 g of protein and 3 g of fiber, plus 47% of the daily value of biotin, 38% of manganese and about 20% each of folate and magnesium. Two meta-analyses of small trials found slightly lower LDL cholesterol and triglycerides in one and no change in body weight in the other, so none of the evidence is strong.
Is quinoa a complete protein?
Yes, by the usual measure. Quinoa contains all nine essential amino acids, and it scores 100 out of 100 on the amino acid score used on this site (the IOM 2002 pattern), with lysine (106) and leucine (108) the lowest. Lab results vary by sample: a 1992 analysis put the chemical score at 86, with the aromatic amino acids limiting, and a 2020 analysis of 100 Washington-grown samples found leucine short for infants. Dry quinoa has 14.1 g of protein per 100 g.
Is quinoa a grain or a seed?
Botanically it is a seed, from a plant in the amaranth family related to spinach, not a grass like wheat or rice. It is called a pseudocereal because it is cooked and eaten like a grain. Some researchers count it with whole grains.
Is quinoa gluten-free?
Quinoa itself has no gluten, but it can pick up gluten from nearby wheat, rye or barley before it reaches you. The FDA allows a “gluten-free” label only below 20 parts per million. In a 6-week trial, 19 celiac patients ate 50 g a day and tolerated it, yet 2 of 15 varieties triggered immune cells in the lab. If you have celiac disease, choose labeled quinoa and ask your care team.
Do you have to rinse quinoa?
Rinsing helps and costs nothing. The seed coat holds bitter saponins, and washing and polishing remove them, so many packages are already pre-rinsed. Oregon State University Extension says to rinse in a fine-mesh strainer when the package does not say it is pre-rinsed. If your quinoa tastes bitter, rinse it again.
Is quinoa better than rice?
It has more protein and fiber, though the calories are about the same. Per 100 g dry, quinoa has 14.1 g of protein, 7 g of fiber and 368 calories, against 7.5 g, 3.4 g and 362 calories for brown rice on this site, and its glycemic index is 53 against an estimated 68. In a 148-person trial, 40 g a day of quinoa did not change cholesterol or blood sugar differently from rice or bulgur after 4 weeks.
Is quinoa good for weight loss?
No study here shows that quinoa on its own causes weight loss. Seven trials pooled in one meta-analysis found no significant change in body weight or BMI, while another pooled 5 trials and found 1.26 kg lower weight. Quinoa is not low in calories, with 156 in ¼ cup dry, but its 3 g of fiber and 6 g of protein can help a meal fill you up.
Is quinoa good for blood sugar and diabetes?
It may help, but the evidence is limited. Quinoa’s glycemic index is 53 on this site, and in a year-long trial in 138 people with impaired glucose tolerance, 7.8% on a quinoa diet developed diabetes against 20.3% of controls. A 4-week trial in 148 adults found no difference from rice or bulgur. If you take diabetes medicine, do not change it because of what you eat without asking your care team.