Taro: a starchy root with a medium to high glycemic index

Taro is commonly described as a low glycemic food. In 10 healthy young adults it had a glycemic index of 69 and a glycemic load of 12 per 50 g of carbohydrate, which is medium to high, second only to brown rice at 82 among five Chinese starchy foods. This is one small study, the abstract does not describe how the taro was prepared, and the index moves with variety and cooking. As a food, taro is mainly starch. The UK table gives raw taro 106 calories and 25.1 g of starch per 3.5 oz (100 g), with 1.4 g of protein. USDA lists copper at 0.172 mg, vitamin B6 at 0.283 mg and vitamin E at 2.38 mg per 3.5 oz (100 g) raw, each under a fifth of the Daily Value. The UK figure for B6 is 0.08 mg, less than a third of that, so the B6 content of taro is uncertain.

The numbers, per 3.5 oz (100 g)

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

How much is actually in it

• USDA puts raw taro at 0.172 mg of copper, 0.283 mg of vitamin B6 and 2.38 mg of vitamin E per 3.5 oz (100 g), each under a fifth of the Daily Value. — USDA SR Legacy record Taro, raw, FDC 169308 (n = 8 records) Evidence E source
  Copper 0.172 mg (19% DV), vitamin B6 0.283 mg (17% DV), vitamin E 2.38 mg (16% DV) per 3.5 oz (100 g) raw; across 8 raw and cooked records copper 0.071 to 0.201 mg and B6 0.072 to 0.331 mg
• The UK food table gives raw taro 106 calories and 25.1 g starch per 3.5 oz (100 g), and only 0.08 mg of vitamin B6, less than a third of the USDA figure. — CoFID 2021 record 13-376 Taro, raw (n = 1 record) Evidence E source
  Energy 106 calories, carbohydrate 26.2 g, starch 25.1 g, total sugars 1.1 g, protein 1.4 g, potassium 360 mg, copper 0.20 mg, vitamin B6 0.08 mg per 3.5 oz (100 g); B6 0.08 against USDA 0.283 mg

What a real portion looks like

• The US dietary survey counts a cup of cooked taro as 160 g and an unspecified portion as 80 g. — FNDDS portion weights for Taro, cooked (71962040) (n = 1 food) Evidence E source
  1 cup 160 g; quantity not specified 80 g; taro also appears as taro chips and cooked taro leaves

What cooking and storage change

• Boiled taro in the UK table holds 200 mg of potassium per 3.5 oz (100 g) against 360 mg raw, a 44% drop, while the USDA group factor for boiled roots predicts only 10% loss. — CoFID 2021 records 13-376 Taro, raw and 13-378 Taro, boiled in unsalted water; USDA retention factor for boiled roots, Vegetables and Vegetable Products group (n = 2 records) Evidence E source
  Potassium 360 to 200 mg, vitamin B6 0.08 to 0.05 mg, starch 25.1 to 21.5 g, energy 106 to 91 calories per 3.5 oz (100 g); USDA Retn_Code 3455 keeps potassium 90%, vitamin B6 90%, copper 95%

What it does to your health

• In 15 prediabetic Indonesian adults, 2 weeks of foods made with 50% taro flour produced no consistent shift in gut bacteria, with only one genus linked to taro intake. — 15 prediabetic adults, randomized double-blind crossover, 2-week periods with 2-week washout (n = 15) Evidence B source
  Microbiota clustered by individual rather than by treatment; only Butyricimonas correlated with taro ingestion

Safety, limits and interactions

• A 91-year-old woman developed swelling of the larynx after biting a boiled root of the ornamental Alocasia odora, which she mistook for edible taro. — 1 woman aged 91, Japan (n = 1) Evidence D source
  Lip, tongue and bilateral arytenoid swelling needing epinephrine and steroids; discharged on day 5
• Across 35 vegetable species, taro was one of the two strongest accumulators of thallium from contaminated soil, with a bioconcentration factor of 0.060. — published data on thallium in vegetables and soils, 35 species (n = 35 species) Evidence C source
  Thallium bioconcentration factor taro 0.060, kale 0.133; taro listed among vegetables posing potential health risks when grown in thallium-contaminated soil

What people believe that the data does not support

• In 10 healthy young adults, taro had a glycemic index of 69 and a glycemic load of 12 per 50 g carbohydrate, second only to brown rice among five Chinese starchy foods. — 10 healthy subjects aged 20 to 30, 50 g available carbohydrate portions (n = 10) Evidence B source
  Taro GI 69 +/- 0.4, GL 12 +/- 0.2, insulinemic index 73 +/- 0.3; brown rice GI 82, adlay 55, yam 52, mung bean noodles 28; all lower than reference bread (P < 0.05)
• Eating about 4.6 oz (130 g) of fresh poi, fermented taro paste, three times a day for 4 weeks did not change gut bacteria counts in 18 healthy adults. — 18 adults aged 19 to 64, crossover, 4 weeks poi against 4 weeks control (n = 18) Evidence B source
  No significant difference in total bacterial counts or in E. coli, Enterobacter, Klebsiella, Lactobacillus, Lactococcus or Bifidobacterium; no change in stool frequency or consistency

Who this works differently for

• In a nationwide survey of 9,982 Taiwanese children, taro and bamboo shoot were the most common vegetable allergens, with vegetable allergy overall at 3.0%. — 9,982 children, nationwide random questionnaire survey, Taiwan 2012 (n = 9982) Evidence C source
  Fruit allergy 5.6%, vegetable allergy 3.0%; taro and bamboo shoot the leading vegetable allergens; symptoms mostly mucocutaneous
• In the Japanese JACC cohort of over 114,000 adults, eating taro, sweet potato and potato was linked to lower kidney cancer death, based on only 48 deaths. — 47,997 men and 66,520 women aged 40 and older, followed about 10 years (n = 114517) Evidence C source
  Taro, sweet potato and potato intake associated with decreased risk of kidney cancer death; 36 male and 12 female deaths; relative risks not in the abstract

The bottom line

Boiling matters if you limit potassium. In the UK table, boiled taro holds 200 mg of potassium per 3.5 oz (100 g) against 360 mg raw, a 44% drop, while the USDA group factor for boiled roots predicts a loss of only 10%. Part of that fall is water taken up during boiling, yet the measured drop is still several times the group factor. A cup of cooked taro weighs 5.6 oz (160 g) in the US dietary survey. Poi, the fermented taro paste, is sometimes called a probiotic. In 18 healthy adults eating about 4.6 oz (130 g) of fresh poi three times a day for 4 weeks, gut bacteria counts did not change, measured by culture only. In 15 prediabetic Indonesian adults, 2 weeks of foods made with 50% taro flour produced no consistent shift in gut bacteria, with only one genus linked to taro intake. In the Japanese JACC cohort of over 114,000 adults, eating taro, sweet potato and potato was linked to lower kidney cancer death. That rests on 48 deaths, with taro grouped with other tubers and no relative risk in the abstract. Who should be careful. In a nationwide questionnaire of 9,982 Taiwanese children, taro and bamboo shoot were the most common vegetable allergens, with vegetable allergy overall at 3.0%, a questionnaire without food challenge. A 91-year-old Japanese woman needed epinephrine and steroids for swelling of the larynx after biting a boiled root of Alocasia odora, an ornamental plant she mistook for taro. Boiling did not make the look-alike safe. Across 35 vegetable species, taro was one of the two strongest accumulators of thallium from contaminated soil, with a bioconcentration factor of 0.060, a finding about mining regions that says nothing about taro from ordinary soils. We found no study on taro in pregnancy or with medicines.

Sources

1. taro-r8-01 · USDA FoodData Central SR Legacy, dataset
   Taro, raw (FDC 169308, SR Legacy, Vegetables and Vegetable Products): copper 0.172 mg per 100 g = 19% DV; vitamin B6 0.283 mg = 17% DV; vitamin E 2.38 mg = 16% DV; range over 8 records copper 0.071-0.201, B6 0.072-0.331; Foundation samples 0
   USDA FoodData Central, SR Legacy, FDC 169308 · checked 2026-09-29
2. taro-r8-02 · CoFID 2021, dataset
   CoFID 13-376 Taro, raw: Energy 106 kcal, Carbohydrate 26.2 g, Starch 25.1 g, Total sugars 1.1 g, Protein 1.4 g, Potassium 360 mg, Copper 0.20 mg, Vitamin B6 0.08 mg per 100 g
   CoFID 2021, Public Health England, code 13-376 · checked 2026-09-29
3. taro-r8-04 · USDA FNDDS, dataset
   Taro, cooked (FNDDS 71962040, fdc_id 2709567, WWEIA Other starchy vegetables): 1 cup 160 g; Quantity not specified 80 g
   USDA FNDDS, fdc_id 2709567 · checked 2026-09-29
4. taro-r8-03 · CoFID 2021 and USDA Retention Factors, dataset
   CoFID 13-376 Taro, raw: Potassium 360 mg, Vitamin B6 0.08 mg, Starch 25.1 g, Energy 106 kcal; CoFID 13-378 Taro, boiled in unsalted water: Potassium 200 mg, Vitamin B6 0.05 mg, Starch 21.5 g, Energy 91 kcal; USDA-RETN-R6:3455 VEG,ROOTS,ETC,BLD,DRAIND,WTR COVER: potassium_mg 90% retained, vitamin_b6_mg 90%, copper_mg 95%
   CoFID 2021 codes 13-376 and 13-378; USDA Table of Nutrient Retention Factors, Release 6, 2007, Retn_Code 3455 · checked 2026-09-29
5. taro-r8-07 · randomized crossover trial
   Only Butyricimonas could be correlated with taro ingestion.
   Nutrients, 2022 · checked 2026-09-29
6. taro-r8-08 · case report
   A 91-year-old woman developed oropharyngeal pain and swelling after biting into a boiled root of Alocasia odora, mistaking it for edible taro.
   Clin Toxicol (Phila), 2025 · checked 2026-09-29
7. taro-r8-10 · meta-analysis of environmental data
   Taro and kale had significantly higher capability to accumulate soil Tl among the 35 species studied, with Tl bioconcentration factor values of 0.060 and 0.133, respectively.
   Sci Total Environ, 2024 · checked 2026-09-29
8. taro-r8-05 · randomized crossover trial
   Among the five starchy foods, brown rice evoked the highest GI and GL at 82 ± 0.2 and 18 ± 0.2, followed by taro (69 ± 0.4, 12 ± 0.2), adlay (55 ± 0.4, 10 ± 0.2), yam (52 ± 0.3, 9 ± 0.0) and mung bean noodles (28 ± 0.5, 7 ± 0.2), respectively.
   World J Gastroenterol, 2010 · checked 2026-09-29
9. taro-r8-06 · randomized crossover trial
   We found no significant differences in total bacterial counts following a poi diet versus following a control diet, nor were significant differences found in counts of specific bacterial species.
   Altern Ther Health Med, 2005 · checked 2026-09-29
10. taro-r8-09 · cross-sectional
    The most common fruit allergen was mango, followed by kiwifruit, whereas taro and bamboo shoot were the most common vegetable allergens.
    Pediatr Neonatol, 2022 · checked 2026-09-29
11. taro-r8-11 · cohort
    A medical history of hypertension, a fondness for fatty food, and consumption of black tea were associated with an increased risk of kidney cancer death while an intake of taro, sweet potato and potato was associated with a decreased risk.
    J Epidemiol, 2005 · checked 2026-09-29