Peas

Field peas are harvested dry, like beans. Kibble makers use them whole and ground, or split the same crop into protein, starch and fiber fractions that each get their own line on the label.¹

1. 01 // Source Dry field peas Mature seeds, about 24% protein and 51% starch on a dry basis.
2. 02 // Process Dehulled or not The hull is 7 to 14% of the seed. Removing it cuts fiber and raises the protein and starch share.
3. 03 // Process Ground to flour Milled fine so the starch cooks evenly in the extruder.
4. 04 // Process Air sorted Optional. Air separates the flour into a protein-rich fraction and a starch-rich one.
5. 05 // Output Peas and fractions Ground peas, or pea protein and pea starch, each listed as its own ingredient.

1. 01

   Calories the dog can use

   Most of a dry pea is starch, and extrusion cooks it into energy a dog digests. Pea diets are absorbed less completely than rice or corn diets, so more of each cup ends up as stool.^1,7

   1. Strong
   2. Some
   3. Thin
   4. None
2. 02

   A gentler insulin response

   In obese beagles fed peas or rice for 12 weeks each, peak insulin after a glucose test was lower on peas. A second trial found later insulin rose more on pea diets, so the evidence is mixed.^7,13

   1. Strong
   2. Some
   3. Thin
   4. None
3. 03

   Extra lysine alongside meat protein

   Pea protein is high in lysine, and its essential amino acids other than methionine digest well. Next to meat it adds usable amino acids. On its own it falls short on methionine.^1,8

   1. Strong
   2. Some
   3. Thin
   4. None

1. 01

   Starch without grain

   Kibble needs starch to expand and hold its shape in the extruder. Peas supply it without grain, which is the whole point of a grain-free label.¹

2. 02

   Protein that counts

   At about 24% protein, peas lift the crude protein figure. The guaranteed analysis does not say whether that protein came from meat or peas.^1,10

3. 03

   A slower glucose rise

   In small dog trials, pea and lentil diets gave a later or lower blood glucose rise than rice or corn diets.^6,7

4. 04

   Supply at scale

   Peas are the largest specialty crop in US dog food: about 95,700 tons in a year, more than twice the beet pulp.¹¹

How much A 20-week trial fed up to 45% whole pulses in a complete diet with no change in heart function.⁵

1. Critics say

   Peas raise the protein figure without meat

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   Crude protein counts protein from any source. Peas are about 24% protein and pea protein concentrate much more, and both run short on methionine, so the number rises without meat's amino acid profile.^1,8

2. Brands say

   Low glycemic, slow-release energy

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   Two small dog trials found pea or lentil diets gave a later or smaller glucose rise than rice or corn. Neither showed a benefit for a healthy dog, and the pea diets were the least digestible.^6,7

3. Brands say

   A good plant protein

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   Pea amino acids were 80 to 90% digestible in the standard bird assay, but methionine runs short. It works as a partner to animal protein, not a replacement.⁸

4. Vets say

   Peas cause heart disease (DCM)

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   FDA found peas in 89% of foods named in DCM reports but says reports cannot show cause. A 28-day trial saw subtle heart changes on a wrinkled pea flour not sold commercially; a 20-week trial at up to 45% pulses saw none.^2,4,5

5. Critics say

   Peas are just filler

   Outruns the evidence

   Evidence

   1. Strong
   2. Some
   3. Thin
   4. None

   Filler has no defined meaning, and peas supply both energy and protein. The fair criticism is digestibility: pea diets digested less well than rice or corn diets in two dog trials.^1,6,7

1. 2023 // Feeding trial, 4 diets, 20 weeks

   Up to 45% pulses left healthy dogs' hearts unchanged⁵

   28 healthy adult Siberian Huskies

   Found. Dogs ate complete diets with 0, 15, 30 or 45% whole pulses, balanced with pea starch, for 20 weeks. Heart ultrasound, NT-proBNP and troponin did not differ among the 4 groups.

   What it means. For a healthy dog on a complete diet, pulses at nearly half the recipe did not harm the heart over about 5 months.

2. 2023 // Feeding trial, 28 days per diet

   Wrinkled pea flour diet caused subtle heart changes⁴

   8 adult Beagles

   Found. A grain-free diet with 58% wrinkled pea flour lowered stroke volume and cardiac output and raised NT-proBNP, though not to the level of disease. Taurine did not change, but methionine fell on every test diet.

   What it means. A real warning sign, but it came from 8 dogs over 28 days fed a diet that was 58% wrinkled pea flour.

3. 2015 // Feeding trial, 2 diets, 12 weeks

   A pea diet lowered insulin response in obese beagles¹³

   16 Beagles: 7 lean, 9 obese

   Found. Glycemic index did not differ between the pea and rice diets, 56 vs 63. After 12 weeks on each diet, obese dogs had lower peak insulin after a glucose test on peas. Weight and heart measures did not change.

   What it means. Peas lowered the insulin response in obese dogs, not their glycemic index. The trial was small and the dogs stayed obese.

4. 2008 // Feeding trial, 6 starch sources

   Pea diets digested less well than grain diets⁷

   36 adult dogs, 6 per diet

   Found. Of 6 starch sources, the pea and lentil diets had the lowest dry matter, organic matter and energy digestibility. Pea, lentil and sorghum diets gave the larger glucose and insulin responses from 30 minutes after the meal on.

   What it means. Pea-based food leaves more in the stool. Its later glucose curve is a real difference, not proof of a health benefit.