Food & nutrition

Soya foods

11 sources · Latest source check 2026-10-20 UTC

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Soy and soya refer to the same plant, Glycine max. Its foods include tofu, tempeh, edamame, miso and soy drinks. Supplements can instead contain soy protein, concentrated isoflavones or other components. These are different exposures, even when all carry the word “soy”.[1]

Common forms are useful for different purposes

Common forms are useful for different purposes
Form	What it is or how it differs
Soybeans and soy nuts	Whole prepared beans and snack forms can provide protein. The amount eaten and preparation differ from the serving of a drink or tofu block.[4]
Tofu	A block made from soymilk, sold from silken or soft through to extra firm. Firmer tofu generally contains less water.[2]
Tempeh	Cooked soybeans are fermented and formed into a firm block. Some packets also contain other grains or beans; tempeh and tofu are distinct foods.[3]
Soy drink	A liquid product whose protein content varies by formulation. Plain and flavoured drinks are not necessarily interchangeable nutritionally.[4]
Soy protein or isoflavone supplement	An ingredient or supplement targeting particular components. Isoflavones have structural similarities to oestrogen, but that does not make every soy product a hormone medicine.[1]

Choose the food that fits the meal

Silken tofu can be blended into sauces; firm tofu is more suited to pieces that hold their shape. Pressing removes water and changes cooking texture, rather than transforming soy into a new health treatment. The Illinois explanation distinguishes these practical uses and notes that baked tofu can be added directly to a meal.[2]

Tempeh has a denser structure and can be sliced or crumbled into dishes such as stir-fries and chilli. The Illinois extension describes it as a complete protein, supplying all nine essential amino acids. Its recipe examples also illustrate why the sauces, oils and other ingredients remain part of the finished food’s nutritional composition.[3]

Protein depends on the actual product

The UCSF composition chart illustrates variation: its examples give 6–13 g of protein for 3 ounces of water-packed tofu, and 3–10 g for 8 ounces of plain soy drink. These are examples, not specifications for all brands. Comparing the label and the amount actually eaten is more informative than assuming that all soy products provide the same protein.[4]

What cholesterol, hormone and cancer studies show

A 2019 review used 46 controlled trials identified by the FDA; 43 contributed data, and 41 contributed LDL results. The typical follow-up was six weeks, with non-soy protein controls. Pooled LDL was approximately 3–4% lower, with differences between trials. This is a measured cholesterol effect, not a trial of heart attacks or mortality. The review evaluated described soy-protein interventions, so it cannot assign that same effect to a spoonful of miso or any product merely containing soy. Several authors disclosed food-industry relationships.[5]

A 2025 review of 11 randomised trials, involving 489 apparently healthy adult men, found no significant overall change in testosterone or free testosterone. Its pooled oestradiol result was also not significant, but subgroup, dose-response and sensitivity analyses suggested possible changes in that hormone under some conditions. The authors emphasised the small evidence base for individual outcomes and the need to separate foods from protein supplements. This supports a narrower conclusion than either “soy feminises men” or “soy can never affect any hormone”. It measured blood hormones, rather than establishing fertility outcomes. The authors reported no funding or conflicts.[6]

A 2019 prospective study followed 300,852 Chinese women aged 30–79 for about ten years. Moderate soy intake was not associated with breast-cancer incidence overall. The same publication’s combined analysis of prospective cohorts found a small association between higher dietary isoflavone intake and lower incidence. That difference is useful context: intake ranges and study methods varied, and observational associations cannot prove prevention. Dietary intake was estimated rather than experimentally assigned. Public and charitable research bodies funded the work. It concerns incident cancer, rather than demonstrating a treatment effect in people with an existing diagnosis.[7]

Food evidence and supplement claims need separate answers

NCCIH distinguishes soy-protein replacement from isoflavones, which may not have the same cholesterol effect. Its adult overview describes inconsistent or small effects for several promoted uses, and notes that soy supplements have not been shown to reduce breast-cancer risk. Digestive side effects and medicine interactions can also differ between products. A concentrated capsule therefore needs its own evidence and ingredient assessment.[1]

Allergen information has a defined jurisdiction

FSA guidance for England, Northern Ireland and Wales lists soybeans and their products among the declarable allergens, with specified exceptions such as fully refined soybean oil.[8]

The curd-setting ingredient can also contribute calcium

A coagulant is an ingredient that makes soymilk form curds. Calcium salts, including calcium sulfate, are among the options; other setting agents include magnesium chloride. Calcium-set tofu can therefore contribute added calcium as part of making the food. The ingredient identifies a process, while the nutrition panel supplies the actual calcium amount.[9]

For concrete examples inspected in October 2026, Cauldron’s Authentic tofu lists calcium sulphate and 405 mg calcium per 100 g. Naked Tofoo lists nigari and states 81.9 mg per 100 g. These formulations differ in more than one way; this is a label comparison, not a trial isolating the setting agent. Neither amount should be assigned to every tofu or future packet.[10][11]

Evidence & uncertainty

The best-supported finding here is a modest LDL-cholesterol reduction in short adult soy-protein trials compared with other proteins. This does not establish that every soy-containing food prevents heart disease. The amount, formulation and food being replaced matter when interpreting the evidence.[5]

Selected-source overview · Independent review pending

Published questions

Which tofu texture suits ordinary cooking?

Selected-source overview · Independent review pending. Read the evidence context.

Silken and soft tofu work well blended into sauces or similar smooth dishes. Firm tofu better holds a shape; pressing can help remove excess water. Extra-firm and baked products have different preparation needs, so the packet and recipe matter.[2]

Evidence behind this answer

All About Tofu
agency condition or prevention explanation · 2023
Selected relevant original official page passages inspected · 6 March 2023; definition, firmness, pressing and cooking uses