Kidney Beans

Overview

Kidney beans provide plant protein, polyphenols, and prebiotic fiber, supporting gut health and neurotransmitter synthesis. Kidney beans have a DIAAS score of 60-65, indicating they are methionine-limited and should be paired with grains for complete amino acid profile.

Within the BRAIN Diet framework, kidney beans are polyphenol-rich and support gut health through prebiotic fiber and polyphenol effects on the microbiome [1].

Key Nutritional Highlights

• Reports on purification and characterization of a phytate-degrading enzyme from germinated oat (Avena sativa) [1]
• Kidney beans provide plant protein, polyphenols, and prebiotic fiber, supporting gut health and neurotransmitter synthesis. [1]
• Kidney beans have a DIAAS score of 60-65, indicating they are methionine-limited and should be paired with grains for complete amino acid profile.
• Kidney beans are polyphenol-rich and support gut health through prebiotic fiber and polyphenol effects on the microbiome.

Food Context

Synergies

• Soak and cook thoroughly to reduce phytates and improve mineral bioavailability; soaking and sprouting reduces phytates in legumes/grains, improving non-heme iron and zinc bioavailability
• Pair with grains for complete amino acid profile; pair with whole grains or seeds for amino acid complementarity
• Pair with vitamin C to enhance iron absorption, with studies showing up to a fourfold increase when consumed together
• Part of grain-legume complementarity strategy; grain-legume complementarity improves essential amino-acid coverage

Essential Amino Acid Profile

Kidney Beans provide a strong plant protein source but are not a complete protein.

Notable amino acids:

• Lysine

Limiting amino acids:

• Methionine and cysteine (DIAAS ~65–70)

Protein pairing strategy:

Kidney Beans are rich in lysine but relatively low in sulfur-containing amino acids. Combining with grains such as rice, oats, or barley helps create a more balanced essential amino acid profile.

Recipes

no recipes found

Nutrient Tables (per 100 g)

Core nutrients

Nutrient	Amount per 100 g	% RDA per 100 g
Energy	333 kcal	—
Protein	23.6 g	—
Total fat	0.8 g	—
Saturated fat	0.1 g	—
Carbohydrates	60 g	—
Sugars	2.2 g	—
Fibre	24.9 g	—

Key vitamins and minerals

Nutrient	Amount per 100 g	% RDA per 100 g
Iron	8.2 mg	45.6%
Magnesium	140 mg	33.3%
Folate	394 µg	98.5%

Reference intakes: US Dietary Reference Intakes for adults (19–50 years; using the higher of male/female values where they differ).

Data provenance (core / micronutrient panel): USDA FoodData Central, Beans, kidney, all types, mature seeds, raw, FDC ID 175193, SR Legacy bulk (April 2018), per 100 g edible portion, last checked 2026-08-15

Substances

Substances admitted through a supported nutrition-table row. Not every table row appears here. Cards are not BRS mappings.

3 substances in this food

Fe²⁺

Iron

Oxygen transport; dopamine synthesis (tyrosine hydroxylase cofactor)

Mg²⁺

Magnesium

Enzymatic cofactor (>300 reactions); neurotransmitters; mitochondria; redox balance

Vitamin B9 (Folate; 5-MTHF)

One-carbon metabolism; methylation; homocysteine recycling

References

[1] Soaking and sprouting reduces phytates in legumes/grains, improving non-heme iron and zinc bioavailability. Greiner & Konietzny 1999. Purification and characterization of a phytate-degrading enzyme from germinated oat (Avena sativa)