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. 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
Protein	25.9 g	—
Total fat	1.3 g	—
Fibre	4.3 g	—

Key micronutrients

Nutrient	Amount per 100 g	% RDA per 100 g
Iron	6.6 mg	36.6%
Zinc	3.3 mg	29.9%
Magnesium	164 mg	39%
Calcium	98 mg	9.8%
Potassium	1490 mg	43.8%

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, Dry, Dark Red Kidney (0% moisture), FDC ID 747440, API, per 100 g edible portion, last checked 2026-03-14

Substances

Substances in this food: editorial (Overview / literature) plus analytical (nutrition table).

6 substances in this food

Iron

Oxygen transport; dopamine synthesis (tyrosine hydroxylase cofactor)

Magnesium

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

Vitamin B9 (Folate; 5-MTHF)

One-carbon metabolism; methylation; homocysteine recycling

Zinc

Cofactor in neurotransmission and antioxidant enzymes; dopamine modulation

Calcium

Bone health; neurotransmission; interacts with vitamin D and K2

Potassium

Electrolyte for nerve transmission, muscle function, and blood pressure regulation

References

• Kidney beans: DIAAS 60-65, Methionine-limited; polyphenol-rich; supports gut health
• Pair with whole grains or seeds for amino acid complementarity; grain-legume complementarity improves essential amino-acid coverage
• Soaking and sprouting reduces phytates in legumes/grains, improving non-heme iron and zinc bioavailability GREINER and KONIETZNY 1999
• Polyphenol-rich legumes support gut microbiome health; polyphenol sources support gut barrier integrity, TLR4 suppression, LPS neutralization, and microglial activation dampening