Tamarind: three small trials, and two answers about gallstones

The best trial on tamarind gave 20 fl oz (600 mL) a day of a 30 percent pulp juice to adults living with HIV whose triglycerides were 150 mg per dL or higher. Over 4 weeks, in 50 people aged 30 to 60, triglycerides fell by 39.8 mg per dL, a 17.3 percent drop, with a confidence interval of 11.9 to 67.7 and no change in total, LDL or HDL cholesterol. The authors describe the study as exploratory and say it was not powered to settle the question. That is 20 fl oz (600 mL) of prepared juice every day, not the way the fruit is normally eaten. The arm that moved systolic blood pressure, by 7.4 mmHg, was the weaker 10 percent juice rather than the stronger one, which is not how a dose response usually behaves. Everything known about this fruit stands on three small trials of fewer than a hundred people in total, plus a few surveys. No systematic review of tamarind exists.

The numbers, per 3.5 oz (100 g)

As people eat it, per 3.5 oz (100 g)

How much is actually in it

• Tamarind pulp carries 0.428 mg thiamin and 92 mg magnesium per 3.5 oz (100 g) by USDA, but the UK dataset finds only 0.29 mg thiamin, a 32 percent gap between two national tables. — reference entries in two national food composition datasets, not a study population Evidence E source
  Thiamin USDA 0.428 mg versus CoFID 0.29 mg per 3.5 oz (100 g); carbohydrate 62.5 versus 56.5 g; magnesium 92 mg in both
• Tamarind holds 2.35 g of fructans per 3.5 oz (100 g), the highest of twenty foods measured for a low FODMAP diet. — laboratory analysis of 20 foods commonly eaten by ethnic minority groups in the United Kingdom (n = 20 foods) Evidence D source
  Tamarind fructans 2.35 g per 3.5 oz (100 g) and galacto-oligosaccharides 0.02 g per 3.5 oz (100 g); next highest fructans were fenugreek seeds at 1.11 g per 3.5 oz (100 g)

What a real portion looks like

• One tamarind weighs 2 g in the US dietary survey. — US survey food portions, FNDDS code 63148750 Evidence E source
  1 tamarind = 2 g; quantity not specified = 2 g

What your body absorbs

• Nobody has studied how tamarind is absorbed: the corpus returns zero records for tamarind with absorption, bioavailability, digestibility or uptake, and zero systematic reviews of any kind. — local PubMed corpus, version pubmed:468905, searched by name across all layers Evidence E source
  15 records for tamarind in total, of which 3 randomized trials and 12 observational; zero on absorption, zero syntheses, zero registered trials in ClinicalTrials.gov, zero rows in the drug interaction layer

What cooking and storage change

• Cooking costs tamarind thiamin but not magnesium: USDA retention factors for dried fruit give 80 percent thiamin left after baking and 95 percent after reheating, with magnesium at 100 percent either way. — USDA retention factors for the food group Fruits and Fruit Juices, applied to tamarind by group Evidence E source
  Dried fruits baked, thiamin 80 percent and magnesium 100 percent; dried fruits reheated, thiamin 95 percent and magnesium 100 percent

What it does to your health

• Drinking 20 fl oz (600 mL) of 30 percent tamarind pulp juice daily for 4 weeks cut triglycerides by 39.8 mg per dL, a 17.3 percent drop, in 50 adults living with HIV. — 50 adults aged 30 to 60 with triglycerides at or above 150 mg per dL, living with HIV, 4 weeks, two doses of juice (n = 50) Evidence B source
  Triglycerides minus 39.8 mg/dL (95 percent CI minus 67.7 to minus 11.9, P = 0.006) on the 30 percent juice; systolic blood pressure minus 7.4 mmHg (95 percent CI minus 14.5 to minus 0.26, P = 0.043) on the 10 percent juice; no effect on total, LDL or HDL cholesterol
• Eating 10 g of tamarind a day for 18 days raised urinary fluoride from 3.5 to 4.8 mg a day in schoolboys, and at the same time cut magnesium excretion from 23.4 to 7.1 mg a day. — 20 healthy boys in India, 18 completed, 10 g tamarind with lunch daily for 18 days on a constant diet (n = 18) Evidence B source
  Fluoride excretion 4.8 plus or minus 0.22 versus 3.5 plus or minus 0.22 mg per day (P below 0.001); magnesium 7.11 versus 23.39 mg per day and zinc 252.88 versus 331.78 micrograms per day, both lower on tamarind

Safety, limits and interactions

• Observational data from southern India link tamarind four or more times a week to gallstones with an odds ratio of 27.6. — 71 consecutive patients with gallstone disease and age and sex matched controls in southern India (n = 71) Evidence C source
  Odds ratio 27.6 (95 percent CI 9.5 to 84.4) for tamarind four or more times per week; spicy foods OR 6.6 and fried foods OR 9.1 in the same model
• Tamarind chili candy is one of the foods counted in a California Proposition 65 dietary exposure survey, and reported intake of it varies by age and ethnicity. — 186 adults and adolescents in Southern California, online dietary survey, March to June 2023 (n = 186) Evidence C source
  No contaminant concentrations measured; intake of tamarind and chili candy differed by age and race or ethnicity, and the authors judge current exposure assessment likely to underestimate single-day exposure

What people believe that the data does not support

• Neither regulator has ever ruled on tamarind: the EU register holds no claim for it and 21 CFR does not mention it at all. — EU Register on nutrition and health claims snapshot 2026-09-21 and 21 CFR part 101 Evidence E source
  Zero entries for tamarind, Tamarindus and tartaric in the EU register of 2330 claims; zero mentions in 21 CFR 101

Who this works differently for

• In 30 adolescent boys from a fluorosis area already drinking defluoridated water, adding tamarind for 3 weeks further raised fluoride excretion and lowered urinary calcium and copper. — 30 adolescent boys in a fluoride endemic area of India, 15 per arm, 2 weeks of defluoridated water first, then 3 weeks with or without tamarind (n = 30) Evidence B source
  Significant rise in fluoride excretion and urinary pH (P below 0.01), fall in urinary calcium (P below 0.01) and copper (P below 0.05) versus control; urine volume unchanged
• Among 2947 adolescents in Burkina Faso, eating tamarind was associated with 25 percent lower odds of anemia. — 2947 school students aged 10 to 18 years in Centre West Burkina Faso, cross-sectional survey in early 2021 (n = 2947) Evidence C source
  Adjusted odds ratio 0.75 (95 percent CI 0.610 to 0.929) for anemia; overall anemia prevalence 36.2 percent

What is still unknown

• A larger study of the same question and the same region found tamarind more than three times a week raised gallstone odds only 1.76 fold, fifteen times smaller than the other estimate. — 346 patients with gallstones, 178 women, and 346 age and sex matched healthy controls in southern India (n = 692) Evidence C source
  Odds ratio 1.76 (95 percent CI 1.05 to 2.96, p = 0.03) for tamarind more than three times per week; BMI above 22 OR 1.49

The bottom line

Two national tables disagree about what is in it. USDA gives raw tamarind 0.428 mg thiamin and 92 mg magnesium per 3.5 oz (100 g), while the UK CoFID entry gives 0.29 mg thiamin and the same 92 mg magnesium, a gap of about a third on the vitamin and none on the mineral. Neither entry carries sample level variation, so nothing in the data says which figure is closer. Portions here are small. One tamarind weighs 2 g in the US dietary survey, and the trials below used 10 g a day. A figure quoted per 3.5 oz (100 g) therefore describes a quantity few people eat at one sitting, unless the pulp goes into a dish as paste. For cooking, USDA publishes retention factors by food group rather than by food, and the group here is Fruits and Fruit Juices, where dried fruit keeps 80 percent of its thiamin when baked and 95 percent when reheated, with magnesium unchanged at 100 percent both ways. The oddest finding about tamarind concerns fluoride. In 18 boys in India who finished an 18 day study on a controlled diet, 10 g of tamarind with lunch each day raised urinary fluoride from 3.5 to 4.8 mg a day. The same portion lowered urinary magnesium from 23.4 to 7.1 mg a day and urinary zinc from 332 to 253 micrograms a day. A second study, in 30 adolescent boys from a fluorosis area who had already drunk defluoridated water for 2 weeks, found that 3 weeks of added tamarind raised fluoride excretion and urinary pH further and lowered urinary calcium and copper. Both were small, both were in boys in India, and both measured urine rather than what stayed in the body. More fluoride leaving in urine is the direction that matters where the water is high in it, but both studies stopped at urine: nobody looked at bone, at teeth or at any symptom. Less magnesium and zinc leaving is harder to read, because nobody measured how much went in. The caution is gallstones, and the two studies of it disagree with each other. Among 71 patients with gallstone disease in southern India, matched to controls by age and sex, tamarind four or more times a week carried an odds ratio of 27.6, confidence interval 9.5 to 84.4. In the same region, a study nearly five times larger, 346 patients against 346 matched controls, put tamarind more than three times a week at an odds ratio of 1.76, interval 1.05 to 2.96. Odds are not risk. An odds ratio of 27.6 built on 71 cases sits in a model that also gives spicy food 6.6 and cooking oil 62, which looks like a whole cuisine measured through one ingredient. Anyone on a low FODMAP diet, the diet used for irritable bowel syndrome, has a steadier reason for care. A laboratory analysis of 20 foods eaten by minority communities in the UK found tamarind highest for fructans at 2.35 g per 3.5 oz (100 g), more than double the next food, and fructans are the class a low FODMAP diet limits. That was an assay of the food rather than a test in patients. One more survey belongs here. Among 186 adults and adolescents in Southern California, reported intake of tamarind and chili candy varied by age and ethnicity, in a paper arguing that Proposition 65 exposure assessments underestimate what people eat in a single day. That survey measured no contaminants in any food. The drug interaction layer holds no row for tamarind, and no card here covers pregnancy, so this page says nothing about either. For a fruit eaten daily across much of the world, the record is thin. Among 2947 school students aged 10 to 18 in Centre West Burkina Faso, where 36.2 percent were anemic, reporting that they ate tamarind went with 25 percent lower odds of anemia, adjusted odds ratio 0.75, interval 0.610 to 0.929. That is a cross sectional association from a food questionnaire, and in the same model washing hands and brushing teeth twice a day looked protective too, which shows how much the survey could not hold still. How tamarind is absorbed has never been studied. A search of the corpus for tamarind together with absorption, bioavailability, digestibility or uptake returned nothing, no synthesis of any kind exists, and ClinicalTrials.gov lists no registered trial. Neither the EU claims register nor 21 CFR mentions tamarind, its genus or tartaric acid, which means nobody has filed a claim rather than that a claim was tested and refused.

Sources

1. tama-r4-01 · food composition datasets
   Tamarinds, raw [FDC 167763]: Thiamin 0.428 mg, Carbohydrate 62.5 g, Magnesium 92 mg per 100 g. Tamarind [CoFID 14-265]: Thiamin 0.29 mg, Carbohydrate 56.5 g, Magnesium 92 mg per 100 g.
   USDA FoodData Central SR Legacy, Tamarinds raw, FDC 167763, and CoFID 2021 code 14-265 · checked 2026-09-25
2. tama-r4-08 · food composition analysis
   Fructans and galacto-oligosaccharides were the major FODMAPs in these foods, including channa dal (0.13 g/100 g; 0.36 g/100 g), fenugreek seeds (1.11 g/100 g; 1.27 g/100 g), guava (0.41 g/100 g; not detected), karela (not detected; 1.12 g/100 g) and tamarind (2.35 g/100 g; 0.02 g/100 g).
   Int J Food Sci Nutr, 2016 · checked 2026-09-25
3. tama-r4-11 · portion dataset
   Tamarind | FNDDS 63148750 | 1 tamarind (62286) 2 g | Quantity not specified (90000) 2 g
   USDA FNDDS, Tamarind, FNDDS code 63148750 · checked 2026-09-25
4. tama-r4-13 · corpus search, null result
   corpus_search.py (tamarind) AND (absorption OR bioavailability OR bioaccessib* OR digestib* OR uptake) --all-types: found 0. ctgov_search.py tamarind: nothing. interact_search.py tamarind: nothing.
   USDA Table of Nutrient Retention Factors, Release 6, 2007, USDA Agricultural Research Service · checked 2026-09-25
5. tama-r4-10 · retention factor dataset
   Fruits and Fruit Juices, FRUITS(DRIED),BAKED [251]: thiamin 80%, magnesium 100%. Fruits and Fruit Juices, FRUITS(DRIED),REHEATED [257]: thiamin 95%, magnesium 100%.
   USDA Table of Nutrient Retention Factors, Release 6, 2007, USDA Agricultural Research Service · checked 2026-09-25
6. tama-r4-02 · randomized controlled trial
   The 30% fruit pulp juice significantly reduced TG by -39.8 mg dL-1 (95% CI: -67.7, -11.9), P = 0.006, corresponding to a 17.3% reduction of the baseline TG levels, while no statistically significant effect was noted for the 10% fruit pulp juice. None of the doses had a significant effect on total cholesterol, LDL, and HDL.
   Food Funct, 2025 · checked 2026-09-25
7. tama-r4-03 · randomized diet-controlled trial
   Each subject consumed 10 g tamarind daily with lunch for 18 days at the social welfare boys' hostel. ... Tamarind intake led to significant increase (P<0.001) in the excretion of fluoride in 24 h urine (4.8+/-0.22 mg/day) as compared to excretion on control diet (3.5+/-0.22 mg/day). However, excretion of magnesium and zinc decreased significantly (7.11+/-1.48 mg of Mg and 252.88+/-12.84 microg of Zn per day on tamarind diet as compared to 23.39+/-3.68 mg of Mg and 331.78+/-35.31 microg Zn per day on control diet).
   Eur J Clin Nutr, 2002 · checked 2026-09-25
8. tama-r4-05 · case-control study
   Tamarind (OR 27.6; 95 % CI 9.5 to 84.4), spicy foods (OR 6.6; 95 % CI 2.8 to 16.3), and fried foods (OR 9.1; 95 % CI 2.8 to 33.2) when taken ≥ 4 times per week and cooking oil ≥ 300 mL per month (OR 62.0; p < 0.0000) increased the risk for GS.
   Indian J Gastroenterol, 2014 · checked 2026-09-25
9. tama-r4-09 · cross-sectional survey
   Results identified root vegetables, rice, leafy greens, pasta/noodles, tea, juice, and seafood to be among the most heavily consumed foods by mass, while the daily intake of many foods such as stuffed grape leaves, tamarind/chili candy and herbs/spices varied by age and race/ethnicity, suggesting that many of Proposition 65's pollution allowances may be exacerbating issues of health inequity and environmental injustice.
   Nutrients, 2025 · checked 2026-09-25
10. tama-r4-12 · claim register search, null result
    euclaims_search.py tamarind: nothing. euclaims_search.py Tamarindus: nothing. euclaims_search.py tartaric: nothing. claims_search.py tamarind: nothing. claims_search.py tartaric: nothing.
    EU Register on nutrition and health claims, snapshot 2026-09-21 · checked 2026-09-25
11. tama-r4-04 · randomized controlled trial
    A randomized, diet control study was conducted in 30 subjects from a fluoride endemic area after significantly decreasing urinary fluoride excretion by supplying defluoridated water for 2 wk. ... There was a significant increase (P < 0.01) in fluoride excretion and urinary pH and a significant decrease in urinary calcium (P < 0.01) and copper (P < 0.05) excretion in the experimental group as compared with the control group.
    Nutrition, 2004 · checked 2026-09-25
12. tama-r4-07 · cross-sectional study
    Among iron-rich foods, tamarind (aOR = 0.75; 95% CI: 0.610, 0.929) and pumpkin leaves (aOR = 0.77; 95% CI: 0.605, 0.974) were associated with lower odds of anaemia.
    Matern Child Nutr, 2025 · checked 2026-09-25
13. tama-r4-06 · case-control study
    There was significant risk of gallstone formation with the use of tamarind when consumed > 3 times a week (OR 1.76; 95% CI 1.05, 2.96; p=0.03). Higher BMI and tamarind use were significant risk factors even on multivariate logistic regression analysis (p=0.02).
    Indian J Gastroenterol, 2005 · checked 2026-09-25