Croutons: toasted bread with a lot of salt

Croutons are toasted bread, and the best trial on what toasting does to blood sugar was run on bread slices, not on croutons. In 10 healthy adults, toasted homemade white bread gave a 2 hour glucose response of 193 mmol min/l against 259 for the same bread fresh, about a quarter lower. Freezing, thawing and then toasting brought it down to 157. A second small trial points the other way. In 17 adults with type 2 diabetes, only potato dumplings came out significantly lower than white bread over 180 minutes, and no difference was reported for 2.1 oz (60 g) of hard toasted bread. Only 8 or 9 of those 17 people ate the toasted bread at all. So the toasting effect held in one group of 10 healthy people, was not seen in a handful of people with diabetes, and neither study put a crouton on the plate. What a crouton reliably brings is salt. A cup, about 40 g, carries around 186 calories and 533 mg sodium in USDA survey data, figures worked out from the per 3.5 oz (100 g) values rather than weighed as a portion.

The numbers, per 3.5 oz (100 g)

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

How much is actually in it

• Plain croutons made with enriched flour carry 37.5 ug selenium, 209 ug folate and 0.623 mg thiamin per 3.5 oz (100 g) in USDA data, and seasoned croutons slightly less. — — (n = 2 records) Evidence E source
  Per 100 g plain: selenium 37.5 ug, folate 209 ug, thiamin 0.623 mg; across plain and seasoned: selenium 28.8-37.5 ug, folate 151-209 ug, thiamin 0.506-0.623 mg

What a real portion looks like

• A cup of croutons weighs about 1.4 oz (40 g) in USDA survey data and supplies about 186 calories and 533 mg sodium, while a fast food packet of 12 g gives about 56 calories and 160 mg sodium. — — Evidence E source
  465 calories and 1333 mg sodium per 3.5 oz (100 g); 1 cup 40 g, 1 fast food package 12 g, 4 cubes 1 g

What your body absorbs

• Lab digestion data suggest hard toasted bread holds no more resistant starch than white bread, with starch breakdown about 30% lower only for potato dumplings. — in vitro alpha-amylase hydrolysis of test foods Evidence D source
  About 30% less starch hydrolyzed after 5 h for potato dumplings than for other foods

What cooking and storage change

• According to the FDA, toasting bread to light brown rather than dark brown lowers acrylamide, and very brown areas hold the most. — general population Evidence E source
  Direction only, no size given
• Pooled food survey data found acrylamide at the highest concentration of three heat-formed contaminants measured in wheat foods such as bread, a mean of about 136 micrograms per kg. — 28 food occurrence studies of wheat-based foods (n = 28 studies) Evidence C source
  Acrylamide 136.29 ug/kg, HMF 70.59 ug/kg, PAHs 0.11 ug/kg

What it does to your health

• In 8 healthy men, a vegetable meal containing 50 g croutons left the stomach more slowly when blended (255 vs 214 min) and was more satiating than the same meal eaten solid. — Eight healthy men, aged 21-28 (mean 24.5) years (n = 8) Evidence B source
  Gastric emptying 255 (SEM 11) vs 214 (SEM 12) min, P < 0.05
• Controlled crossover data link croutons or cookies carrying 25 g soybean fiber a day for 8 weeks with a 5 to 11% drop in total cholesterol in 31 adults with raised cholesterol. — Free-living volunteers with mild to moderate hypercholesteremia (n = 31) Evidence C source
  Total cholesterol -11% (252 to 224 mg/dl) fiber first, -5% (241 to 230 mg/dl) fiber second

Safety, limits and interactions

• Observational data from 36,994 European adults tie at least half of dietary acrylamide to two groups, bread, crisp bread and rusks, and coffee. — 36 994 men and women, aged 35-74 years (n = 36994) Evidence C source
  At least 50% of acrylamide intake across centers; mean intake 13-47 ug/day in men

What people believe that the data does not support

• Toasting fresh white bread cut the 2 hour blood glucose response by about a quarter (IAUC 193 vs 259 mmol min/l) in 10 healthy adults, and freezing then toasting cut it by about 40%. — Ten healthy subjects (three male, seven female), aged 22-59 years (n = 10) Evidence B source
  IAUC 193 vs 259 mmol min/l toasted vs fresh homemade bread (P<0.01); 157 mmol min/l frozen, defrosted and toasted

Who this works differently for

• In 17 adults with type 2 diabetes, 2.1 oz (60 g) of hard toasted bread was not reported to lower the 180 minute glucose response compared with 90 g white bread at 50 g carbohydrate, while potato dumplings did. — Seventeen patients with type 2 diabetes (eleven men and six women) (n = 17) Evidence B source
  No reported difference for hard toasted bread vs white bread; potato dumplings lower at 90, 120 and 150 min

The bottom line

A fast food packet of croutons weighs 12 g and gives about 56 calories and 160 mg sodium, again scaled from 100 g. Per 100 g, plain croutons list 37.5 ug selenium, 209 ug folate and 0.623 mg thiamin, and seasoned ones slightly less. These are single USDA records with no spread across samples, and the folate and thiamin come from enriched flour. In lab digestion, hard toasted bread held no more resistant starch than white bread. Browning is the part you control. The FDA advises toasting bread to light brown, since very brown areas hold the most acrylamide, and it gives no size for the difference. Pooled food surveys put acrylamide at a mean of about 136 micrograms per kg in wheat foods such as bread, with croutons never measured on their own. Among 36,994 European adults, at least half of dietary acrylamide came from two groups, bread with crisp bread and rusks, and coffee. Croutons were not split out of that bread group. We found no data on croutons for pregnancy, children, kidney disease or drug interactions, so the cautions here are the sodium and the acrylamide above. One old trial used croutons only as a carrier. In 31 adults with raised cholesterol, croutons or cookies carrying 25 g of soybean fiber a day for 8 weeks went with a fall in total cholesterol of 11% in one order of the crossover and 5% in the other. Randomization was not stated, and the fiber did the work. Ordinary croutons contain no such thing.

Sources

1. crt-daily-r1-09 · food composition dataset
   Croutons, plain (FDC 172751, SR Legacy): selenium 37.5 ug, folate 209 ug, thiamin 0.623 mg per 100 g; across 2 records (plain, seasoned): selenium 28.8-37.5 ug, folate 151-209 ug, thiamin 0.506-0.623 mg
   USDA FoodData Central, SR Legacy, FDC 172751 (Croutons, plain) · checked 2026-09-28
2. crt-daily-r1-10 · reference dataset
   Croutons, FNDDS 51185000: 1 cup 40 g | 1 fast food package 12 g | 4 cubes 1 g | Quantity not specified 5 g || Energy 465 kcal per 100 g | Sodium 1333 mg per 100 g
   USDA FNDDS 2021-2023, Croutons, food code 51185000, fdc_id 2707697 · checked 2026-09-28
3. crt-daily-r1-03 · in vitro digestion
   The percentage of starch hydrolysed after 5 h in vitro hydrolysis with alpha-amylase was about 30 % lower for potato dumplings than for the other foods. However, no differences in the resistant starch content, the rate of diffusion of simple sugars added to a dialysis tube containing the food, and the viscosity of digesta were observed among the test foods.
   Br J Nutr, 2001 · checked 2026-09-28
4. crt-daily-r1-06 · agency guidance
   Toasting bread to a light brown color, rather than a dark brown color, lowers the amount of acrylamide (see Picture B). Very brown areas should be avoided, since they contain the most acrylamide.
   US FDA, Acrylamide and Diet, Food Storage, and Food Preparation, 2024 · checked 2026-09-28
5. crt-daily-r1-07 · systematic review of occurrence data
   Of the 1479 results, 28 were included for a meta-analysis. Most studies (69.7%) evaluated acrylamide in bread, cookies, and pasta, while PAHs (26.2%) were determined mainly in wheat grains and pasta. HMF was the least determined contaminant (4.1%), with only four studies on cookies included in the meta-analysis. The highest concentration was for acrylamide (136.29 µg·kg-1) followed by HMF (70.59 µg·kg-1) and PAHs (0.11 µg·kg-1).
   Crit Rev Food Sci Nutr, 2023 · checked 2026-09-28
6. crt-daily-r1-04 · randomized crossover trial
   Eight healthy men, aged 21-28 (mean 24.5) years were given two meals (cooked vegetables 250 g, cheese 35 g, croutons 50 g and olive oil 25 g, total energy 2573 kJ, with water 300 ml) differing only in physical state: SM and HM. ... Furthermore, the overall gastric emptying time was significantly slowed (255 (SEM 11) min after HM v. 214 (SEM 12) min after SM; P < 0.05)
   Br J Nutr, 1998 · checked 2026-09-28
7. crt-daily-r1-05 · controlled crossover trial
   Free-living volunteers with mild to moderate hypercholesteremia added 25 gm soybean polysaccharide or starch placebo in crouton or cookie form to their normal, daily diets. A total of 31 persons completed the blind, crossover design, 8-week, experimental protocol. Subjects ingesting soybean polysaccharide prior to placebo showed an 11% decrease (from 252 to 224 mg/dl) in total plasma cholesterol; those who followed placebo with fiber showed a 5% decrease (from 241 to 230 mg/dl).
   J Am Diet Assoc, 1985 · checked 2026-09-28
8. crt-daily-r1-08 · cross-sectional
   In this cross-sectional analysis, 36 994 men and women, aged 35-74 years completed a single, standardized 24-hour dietary recall using EPIC-Soft. ... At least 50 % of AA intake across centers came from two food groups "bread, crisp bread, rusks" and "coffee."
   Eur J Nutr, 2013 · checked 2026-09-28
9. crt-daily-r1-01 · randomized crossover trial
   compared to the fresh homemade bread (IAUC 259 mmol min/l), IAUC was significantly lower when the bread was frozen and defrosted (179 mmol min/l, P<0.05), toasted (193 mmol min/l, P<0.01) and toasted following freezing and defrosting (157 mmol min/l, P<0.01)
   Burton P, Lightowler HJ. The impact of freezing and toasting on the glycaemic response of white bread. Eur J Clin Nutr, 2008 · checked 2026-09-28
10. crt-daily-r1-02 · randomized crossover trial
    an equivalent amount of carbohydrate provided by one (n 8) or two (n 9) of three other different test foods (g): pizza 85, potato dumplings 165, hard toasted bread 60. Foods had a similar nutrient composition. Plasma glucose response, measured for 180 min, was significantly lower after the potato dumplings than after white bread at 90 (P < 0.05), 120 (P < 0.01), and 150 (P < 0.05) min.
    Br J Nutr, 2001 · checked 2026-09-28