What is Soy Protein?

Soy beans next to a glass of milk and the text 'What is soy protein?'

Soy protein is a plant-based powerhouse many people enjoy as an alternative to animal- and dairy-based proteins. It offers a range of health benefits and is popular among vegans, vegetarians and fitness enthusiasts. This article will explore what soy protein is, its advantages and how to incorporate it into your diet.

Soy Protein Explained

Soy protein is made from soya beans and is a by-product of soybean oil. Essentially, it’s what’s left of soybeans after producers hull, grind and remove the fat. This lactose-free protein source contains little to no cholesterol or saturated fat and is commercially available as flour, concentrate or isolates.

Manufacturers refine soy protein isolate, which has a neutral taste and a minimum protein content of 90%. This type is usually found in vegan protein shakes and snacks and is sometimes used as a meat substitute.

Soy protein concentrate, which is about 70% protein, is commonly used as a functional or nutritional ingredient. Soy protein flour, which has the lowest protein content, at just 50%, is often used in gluten-free baking.

Soy Protein vs Whey

Soy and whey protein are popular supplements enjoyed in shakes, meal replacements and delicious high-protein meals and snacks. While soy protein is vegan, whey protein is derived from milk and is unsuitable for vegans or those who are lactose intolerant.

Whey protein contains more essential amino acids per gram and has a higher net protein utilisation (NPU) score at 92-96% compared to soy protein’s 61-65%. A higher NPU score means the body uses a higher percentage of the amino acids supplied.

Soy and whey proteins are both effective supplements. The best choice depends on your personal preference and individual health, lifestyle and nutrition goals.

Soy Nutrition

In addition to plant-based protein, soy contains important vitamins and minerals. Just 28g of soy protein powder contains:

Iron: ~5 mg
Calcium: ~20–50 mg
Magnesium: ~50 mg
Potassium: ~300 mg
Phosphorus: ~200 mg
Zinc: ~1.2 mg
Sodium: ~200 mg (varies by brand)
Folate (Vitamin B9): ~35–50 mcg
Thiamine (Vitamin B1): ~0.1 mg
Riboflavin (Vitamin B2): ~0.1 mg

Soy Protein Benefits Explained

Soy protein provides a range of health benefits. Let’s take a look at some of the most significant.

It may protect the heart

Research suggests that soy foods may be beneficial for heart health. A review of 35 studies discovered that soy intake lowered harmful low-density lipoprotein (LDL) cholesterol and raised beneficial high-density lipoprotein (HDL) cholesterol. Higher levels of LDL cholesterol are associated with heart disease, strokes and heart attacks.

It may support blood sugar levels

Soy foods are associated with better blood sugar control, which is significant for people at risk of or living with diabetes. Other research suggests that fermented soy foods may help mitigate the effects of diabetes. Additionally, a meta-analysis of 15 studies tied soy protein intake to a lower risk of diabetes, although more research is needed to understand its benefits fully.

It keeps you fuller for longer

Soy protein is known for its satiating properties, helping to reduce cravings, curb hunger and temporarily boost metabolism. When eaten, the protein triggers the release of satiety-related hormones, such as cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1), which signal the brain to reduce appetite. Additionally, soy protein slows the rate at which food leaves the stomach, prolonging the sensation of fullness.

It contains all nine essential amino acids

Soy protein contains all nine essential amino acids vital for protein synthesis and nutrient absorption and contributes to a wide range of other bodily functions. The nine amino acids are:

Histidine: Essential for producing histamine, which aids immune function, digestion and sleep.
Isoleucine: Aids muscle metabolism, immune function and energy regulation.
Leucine: Key for producing protein and growth hormones integral to tissue repair and wound healing.
Lysine: Assists with hormone regulation and is essential for producing carnitine, a nutrient that converts fatty acids into energy.
Methionine: A powerful antioxidant that promotes healthy hair and skin while aiding in mineral absorption.
Tryptophan: Supports neurological function and sleep regulation by contributing to the production of melatonin and serotonin.
Threonine: Essential for protein synthesis and lipid metabolism, which aids the liver digest fats and fatty acids.
Valine: Contributes to various bodily functions, including muscle tissue damage prevention, blood sugar level control and nervous system maintenance.

Are There Any Side Effects of Soy Protein?

Soy protein ranks among the safest food supplements on the planet. However, it can cause allergic reactions and, in some cases, bloating and digestion issues.

People with hypothyroidism should also avoid soy, as it might worsen the condition in people with low iodine levels. Soy might also cause interactions with warfarin, tamoxifen and medications for depression (MAOIs). As always, speak with your doctor or dietitian before taking new supplements.

Taking Soy Protein With Other Supplements

Soy protein is a slow- to moderate-release protein, making it an excellent complement to other protein sources in your diet. Popular combinations include soy protein with creatine, oats, Branch Chain Amino Acids (iBCAA) and glutamine. How to include soy protein in your diet

Soy protein allows the body to process other foods more effectively into energy, so combining it with foods you already eat is very beneficial. There are many ways to include soy protein in your diet, from making protein bars to adding soy protein to your morning oats. Add your favourite fruit, nuts, seeds and flavourings such as chocolate, nut butter, cinnamon and syrup for a nutritious and delicious breakfast.

Soy Protein Shakes

Soy protein shakes are a popular and convenient way to include it in your diet. It’s easy to make your own by mixing soy protein powder with water or milk. Get creative and add fruits, chocolate and nuts for a flavour-packed shake.

Enjoy Soy Protein With Protein Works

If you’re looking for high-quality soy protein powder, we offer a range of soy protein shakes and vegan meal replacements to help you get all the plant-based protein your body needs.