Ingredient

Soy Protein Isolate

Flagged in 17

What is Soy Protein Isolate?

Soy Protein Isolate is a highly refined protein derived from soybeans. The process involves removing most of the fats and carbohydrates, leaving a powder that is about 90% protein. It is commonly used as a food ingredient and a supplement due to its high protein content.

It is used in foods to boost protein content, and it is popular in protein bars, shakes, and some baked goods. There is ongoing debate about the health impacts of soy, with some research suggesting potential hormonal effects due to phytoestrogens, though conclusive evidence is lacking. Generally, it is considered a high-quality plant-based protein.

When you see Soy Protein Isolate on a label, it usually indicates a focus on adding protein content, often in products aimed at those looking to increase protein intake like athletes or vegans.

Commonly found in: protein bars, protein shakes, meal replacements, baked goods, cereal

What to watch

  • Soy contains phytoestrogens, which some studies suggest may have hormonal effects, though evidence is not conclusive.

Benefits

  • It provides a high-quality plant-based protein source beneficial for vegetarians and vegans.
  • Soy Protein Isolate is low in fats and carbohydrates, making it suitable for low-carb diets.
FDA

Soy protein is generally recognized as safe (GRAS) by the FDA and widely used in food products.

Research

Research shows mixed results regarding the impact of soy on hormone levels, with no strong consensus.

Vegan

Soy Protein Isolate is plant-derived and commonly accepted in vegan diets.

Sources: GRAS Notice Inventory · Soy Protein

Scout's take

Soy protein isolate is a heavily processed protein extracted from soybeans using chemical solvents like hexane. The majority of soy in the US is genetically modified. It contains phytoestrogens that may disrupt hormonal balance and is used as a cheap filler protein inferior to whey in bioavailability.

The case against

Typically GMO-derived. Extracted using chemical solvents. Contains phytoestrogens that may affect hormone levels. Inferior bioavailability compared to whey.

from the analysis of Barebells Protein Bar · echoed in 1 other analysis

May contain residual solvents from processing and can interfere with hormone balance due to phytoestrogens.

from the analysis of THINK THIN, BROWNIE CRUNCH HIGH PROTEIN BAR

May contain phytoestrogens that could affect hormone balance in sensitive individuals.

from the analysis of KIND ALMOND BUTTER WHOLE GRAIN CLUSTERS

May contain phytoestrogens that can affect hormone balance and is a common allergen.

from the analysis of MISFITS Brownie Batter Protein Bar

Potential allergen and may affect thyroid function in sensitive individuals.

from the analysis of MISFITS Caramel Fudge Protein Bar

The case for

Provides a plant-based protein source for those avoiding animal products.

from the analysis of THINK THIN, BROWNIE CRUNCH HIGH PROTEIN BAR · echoed in 1 other analysis

More from Scout's analyses

Heavily processed protein extracted using chemical solvents like hexane. Typically GMO-derived. Contains phytoestrogens. Used as cheap filler protein.

from the analysis of FitCrunch Peanut Butter Protein Bar

Soy protein isolate is a highly processed form of soy protein. It provides a plant-based protein source but lacks the complete amino acid profile of animal proteins. Processing can reduce the bioavailability of nutrients.

from the analysis of KIND ALMOND BUTTER WHOLE GRAIN CLUSTERS

Soy protein isolate is a highly processed form of soy protein. It lacks the complete amino acid profile found in animal-based proteins. The processing methods may also involve chemicals that raise health concerns.

from the analysis of THINK THIN, BROWNIE CRUNCH HIGH PROTEIN BAR

Found in 17 products

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