Why Soy?

There is compelling evidence that following a plant-based diet can change your life for the better. Swapping animal-based-protein sources for plant-based-protein sources can help you lose weight, live longer, and even combat disease. Of course, one of the best sources of plant protein is the humble soy bean! Soy beans are an incredibly diverse and important food source, with scientifically proven health benefits. Why then, are consumers questioning its inclusion in daily diets?

Twenty or more years ago, concerns were raised about the safety of SOY due to its levels of phytoestrogens – with suggested negative consequences to human health. The 2000s have seen literally thousands of research papers published across the globe, investigating health concerns and also health benefits of SOY, not least of all because in general Asian populations NOT consuming westernized diets tend to have better health, fewer lifestyle diseases including hormonally-driven cancers, and greater longevity than their Western counterparts.  The overwhelming bulk of evidence points distinctly in the direction of the VAST health BENEFITS of SOY, including PROTECTIVE QUALITIES provided by the phytoestrogens occurring in the soy bean, firmly negating all negative concerns raised in the 1990s! These health benefits can only be achieved if SOY is consumed in some or another format (soy milk, soy meat substitutes e.g. soya patties, and soy-based porridges e.g. Soya Life porridge, to name but a few sources), on a DAILY BASIS.

Where do we find SOY?

Whole soybean foods

  • Full fat flour – made from whole soybeans (has the same protein, fat and fibre content as the whole bean).
  • Soymilk – made from ground soybeans that are mixed with water to form a milk-like liquid. Excellent source protein, B-vitamins and iron. Low levels of saturated fat and no cholesterol.

Soy Protein Products

  • Defatted soy flakes (derived from the extraction process of soybeans) are used to make:
    • Soy flour: 86% protein, no fibre, no carbohydrates, no fat. Used in BAKING.
    • Soy concentrates: 65% protein, retain most of the soybean’s dietary fibre. Adds texture to foods.
    • Soy Isolates: 90% protein; extremely versatile; chief component of many dairy-like products (cheese, soymilk, infant formula, non-dairy frozen desserts); also used to make meat products more juicy and nutritious.

Traditional Asian soy products

  • Tofu – soybean curd
  • Miso – thick, high-protein paste made from soybeans, salt and a fermenting agent
  • Natto – fermented, cooked whole soybeans
  • Soybean sprouts – eaten raw in salads / stir-fry’s; rich in Vitamins A, B and C
  • Tempeh – Whole cooked soybeans infused with a culture to form a chewy cake
  • Soy sauce – high in sodium, rich in flavour: made from whole soybeans, wheat flour, fermenting agents: fermented for about 18months.


  • Superior Plant PROTEIN
  • Low GI (Glycaemic Index) CARBOHYDRATE
  • Healthy FAT source with FDA-approved health benefits
  • Essential micronutrients


Soy meets the requirements as a superfood in:

  • Prevention of disease
  • Treatment of chronic disease

RESEARCH SHOWS SOY has benefits for:

  • Children
  • Women’s Health
  • Heart Health
  • Metabolic Syndrome and Diabetes
  • Colon health

Let’s look at the details…


Superior Plant PROTEIN

AMINO ACIDS are the building blocks of PROTEINS: there are 9 essential amino acids, all of which are found in soy protein and many animal foods:

Histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine.

In the 90s, and subsequently confirmed repeatedly in the 2000s, the nutritional value of processed soy protein (isolated soy proteins and soy-protein concentrates) in human protein and amino acid nutrition was evaluated based on a review of studies of growth and nitrogen balance in infants, children, adolescents, and adults.

Findings show that well-processed soy-protein isolates and soy-protein concentrates can serve as the major, or even sole, source of protein intake and that their protein value is essentially equivalent to that of food proteins of animal origin.

The importance of the sulfur amino acid content of soy protein for practical human nutrition has also been examined from nitrogen-balance data. Under conditions of an anticipated normal usage of soy protein, methionine supplementation is not only unnecessary but may even be undesirable for young children and adults. However, for newborns, the data suggest that modest supplementation of soy-based formulas with methionine may be beneficial.

Soy proteins have also been found to be of good quality to include in hypocaloric diets for weight reduction in obese subjects.

Finally, the data indicate that soy proteins are well-tolerated and of good acceptability.

(This information was sourced from the J Am Diet Assoc. 1991 July.)


Unlike most other plant-based protein sources, quinoa and soy products provide all of the essential amino acids.

A cup of cooked quinoa: 8 grams of protein

90g serving of tofu: 6 grams of protein

a cup of soybeans: 29 grams of protein

Other beans and nuts:

  • don’t contain all the amino acids
  • do provide significant amounts of protein
  • Beans per cup: 15 – 17 grams of protein per cup
  • Nuts and seeds per 30g: 4 – 9 grams of protein

Low GI (Glycaemic Index) CARBOHYDRATE

Soy Foods are Low GI (sustains blood glucose levels for several hours, and thus sustains energy levels; as well as preventing diabetes, metabolic syndrome and insulin resistance)

Healthy Fat with FDA-approved health benefits

NEW Qualified Health Claim (QHC) 2017

  • Soybean Oil
    • +/- 85% unsaturated (HEALTHY!) fats
    • NO cholesterol
    • Unsaturated fats have been proven to lower blood cholesterol levels
    • Rich in 2 essential fatty acids: linoleic and linolenic acids, which are not produced by the body, yet are essential to human health.
  • New QHC: 20.5g of soybean oil may reduce the risk of Coronary Heart Disease. It must replace Saturated Fat and must not increase the total calories.




Soy Fibre

  • Soybeans are an excellent source of dietary fibre (found in the outer hull):
    • 6g fibre/1 cup cooked soybeans
    • the extracted hull is often used as a fibre additive for breads, cereal and snacks
    • Both soluble and insoluble fibre is found in soybeans
    • Soluble fibre is proven to assist with lowering of blood cholesterol levels, and controlling of blood glucose (sugar) levels
    • Insoluble fibre increases stool bulk, may prevent colon cancer, and can assist in reducing symptoms of irritable bowel syndrome

Essential micronutrients

Many essential vitamins, minerals and trace elements occur naturally in soybeans – completing its already excellent nutritional profile.


A Superfood / Functional Food is a food that has:

  • Proven benefits in normal health: i.e. PREVENTION of chronic diseases of lifestyle
  • Plays a role in TREATMENT of Lifestyle Diseases

Soy meets the requirements for a SUPERFOOD in:

  • Prevention of disease:
  • Cardiovascular disease: (Curr Pharm Biotechnol: April 2012)
  • Diabetes: (Nutrition Reviews 2009)
  • Hypertension: (J Hypertens: Feb 2013; Nutr Metab Cardiovasc Dis: June 2012)
  • Certain Cancers: (BMC Cancer: May 2013; Anticancer Res: Jan 2013; Epigenomics:Dec 2011)


  • Treatment of chronic disease:
  • Diabetes: Type 1 and Type 2
  • Hypertension
  • Obesity
  • Colon disorders

Are there any negatives for SOY?    DID YOU KNOW…

LESS THAN 0.5% of the population is allergic to soy…

Everyone else derives health benefits from including soy in their DAILY diets


  • Children
  • Women’s Health
  • Heart Health
  • Diabetes
  • Colon health


Start introduction of soy from a young age

Did you know…….

Planta Medica: May 2013 (an observational study) showed that:

“ …the timing of exposure (to soy isoflavones) is one of the most important determinants of beneficial health effects from soy foods….”

“most likely the result of gut microbiota, which colonize the intestine during childhood and facilitates the hydrolysis of glycosides and the formation of equal from daidzein, a pathway that may result in beneficial health effects.


Nutrition Reviews, Vol. 63, No. 8 273 Aug 2005

  • Soy benefits oestrogen metabolism in the body
  • Soy may reduce the risk of osteoporosis
  • Help alleviate menopausal symptoms such as hot flushes
  • Breast cancer prevention


OESTROGEN = the group of female hormones

  • Estradiol
  • Estrone and Estriol

Function – (wide range of actions, affect all systems in the body):

  • growth, function of body tissues (reproductive and others)
  • bone formation and maintenance
  • heart protection
  • influence behaviour and mood
  • also have a role in male tissues (prostate and testes)


  • Oestrogens are synthesized from cholesterol in the ovaries.

Adult women (normal menstrual cycles) secrete 70-500mcg estradiol/day from their ovarian follicles.

This estradiol is used, metabolised and its end product is excreted in the urine.

Estradiol is also produced (smaller amounts) in fat cells, skin, bone, and other tissues.

After menopause most oestrogen in the body is produced in the peripheral tissues of the body; also manufactured in body fat (the total oestrogen produced after menopause is far less than that produced during a woman’s reproductive years)


Oestrogens circulate in the body bound mainly to the sex hormone binding globulin (SHBG).

If levels of SHBG drop then some oestrogens are unbound which result in increased oestrogen exposure, which can enter certain tissues in the body, causing tissue changes and potential damage (e.g. endometriosis, PMS and, in extreme cases breast / ovarian cancers).

Dietary factors can increase SHBG in the body which will result in improved oestrogen metabolism and less potential damage caused by excessive oestrogen exposure.


Lifestyle factors that increase the body’s production of oestrogen:

  • Obesity – increased oestrogen production in fat tissue = increased  oestrogen exposure
  • Excess insulin in the blood stream prompts the ovaries to secrete excess testosterone and reduces SBHG levels, thus increasing levels of free oestrogen
  • Alcohol consumption –increases oestrogen levels

Other factors increasing oestrogen production:

  • Oral Contraceptives and HRT
  • Environmental toxin(e.g. certain pesticides, which structurally similar to oestrogens and can mimic harmful oestrogens in the body)


  • Manage weight
  • Reduce fat and increase fibre
  • **Increase intake of phytoestrogen-rich foods such as SOY : reduces excess oestrogen exposure  = reduced risk of developing breast cancer
  • Cruciferous vegetables (broccoli, cabbage) = rich in Indole-3-Carbinol (I3C)
  • Complex carbohydrates (wholegrains, fruits, vegetables) = improved blood glucose, insulin levels
  • Omega 3 oils to improve oestrogen metabolism.
  • Adequate, not excessive LEAN protein foods : lean meat, chicken, fish, low fat dairy, eggs, nuts
  • Vitamin E  ↓levels of unbound oestrogen; improves PMS; inhibits growth of breast CA cells
  • Magnesium improves oestrogen metabolism; promotes oestrogen detox; ↓PMS symptoms
  • B Vitamins (decreased levels can disrupt oestrogen detoxification = increased levels of circulating oestrogens
  • Other beneficial Phytonutrients:

               – Curcumin (turmeric) + soya isoflavones = reduce levels of unbound oestrogen

               – Antioxidant nutrients (vitamins E and C, and selenium)

               – D-limonene (oils of citrus fruit): promotes the detoxification of oestrogen

**PHYTOESTROGENS – what are they?

Phytoestrogens are plant compounds that can beneficially influence oestrogen synthesis and metabolism through a variety of mechanisms.

NB: Phytoestrogens are currently being extensively investigated as a potential alternative therapy for a range of conditions associated with oestrogen imbalance:

  • menopausal symptoms
  • PMS
  • Endometriosis
  • PCOS
  • Prevention of breast and prostate cancer
  • Protection against cardiovascular disease and osteoporosis

There are 2 types of phytoestrogens: ISOFLAVONES and LIGNANS


Found in:

  • Soy (most common food source of isoflavones)
  • Legumes, alfalfa, clover, liquorice root, kudzu root

Higher intakes of soy products and isoflavones (traditional Japanese diets) are associated with low rates of hormone-dependant cancers 

Did you know….

The average isoflavone intake of:

Japanese women = 20-80mg / day

American women = 1-3mg / day


  • Are antioxidants
  • Are the active components in the soy bean responsible for 75% of the beneficial effects of soy-based foods in human health

Functions of Soy Isoflavones:

  1. When oestrogen levels are high, isoflavones block the more potent forms of oestrogen produced by the body – may help prevent hormone-driven diseases, such as breast and prostate cancer.
  2. When oestrogen levels are low  (after menopause)  isoflavones substitute for the body’s own oestrogen – reduce hot flushes and may assist in ↑bone mineral density which will assist in preventing osteoporosis
  3. Proven cholesterol-lowering effects – assist in the prevention of hyperlipidaemias and CVD
  4. Lowers blood pressure in those with hypertension   (but not in normotensive subjects) 2012

How much Soy Isoflavones are necessary to obtain health benefits?

  • Most experts say that one should obtain the soy isoflavones required from food (not capsules).
  • 1-2 servings a day will most likely provide adequate soya isoflavones:   (40-60mg)

               1 serving = 1 cup soya milk or ½ cup (50g) soya porridge

Where are Soy Isoflavones found?

Source                                                                mg/serving of soy food


               Full fat                                                               177.89

               Textured                                                            148.61

               Defatted                                                             131.19

ROASTED SOY NUTS:                                                       176.94

TEMPEH:                                                                          43.52

MISO:                                                                               42.55

TOFU:                                                                               27.91

SOY MILK:                                                                        9.65

SOY SAUSAGE:                                                                 3.75


Found in:              Fibre-rich foods, such as

  • Flaxseed , other oil seeds
  • Wholegrains
  • Legumes  including soya
  • Vegetables

These foods are fermented in the intestine which are converted into lignans

Health Benefits:

  • Stimulate the production of SHBG in the liver thus reducing levels of free oestrogen circulation
  • They directly decrease the conversion of testosterone to oestrogens in fat and breast cells


  • Soya Milk
  • Soya Life Meal Replacement Shake
  • Soya Life Breakfast Porridge
  • Soya Life Premium Porridge 

Soy in PREVENTION and TREATMENT of: Cardiovascular disease

Soy Foods:

  • Lower LDL-cholesterol
  • Lower triglyceride levels
  • Reduce total cholesterol  (soy isoflavones /plant sterols)
  • Lower blood pressure in those with hypertension
  • Essential fatty acids found in soya products (omega-3 and omega-6 fatty acid): Protect cell membranes (including blood vessel lining): admitting healthy nutrients and barring damaging substances, i.e. protecting one from developing atherosclerosis, and thus protective against heart disease
  • Soya products do not contain and of the unhealthy saturated fats which accelerate a build-up of plaque in the arteries.

Soy in PREVENTION and TREATMENT of: Diabetes

Soy Fibre:

  • Stabilizes blood glucose levels
  • Is Low GI (stabilizing blood glucose levels)
  • Reduces risk of diabetic complications (eye / CVD / renal)

Soy in PREVENTION and TREATMENT of: Colon Disorders

1. Soy has both SOLUBLE and INSOLUBLE Fibre:

Soluble Fibres: enhance colon function and help bulk stools

Insoluble Fibres:protect the colon villi integrity

2. Prebiotics found in SOY:enhance probiotic function (Useful in prevention AND treatment of IBS)

Consumer attitudes 2017:

Soy Myths

Male feminization

  • Clinical studies show neither soy foods nor isoflavones affect testosterone levels or sperm or semen parameters or otherwise exert feminizing effects.
  • Soy protein enhances lean tissue accretion and strength in response to resistance exercise

Soy and breast cancer patients

Clinical studies investigating the effects on markers of breast cancer risk, and epidemiologic studies evaluating recurrence and mortality:

  • Soy foods can be safely consumed by women with breast cancer. This conclusion is consistent with the positions of the American Cancer Society and the American Institute for Cancer Research.
  • In addition, the European Food Safety Authority concluded that isoflavone supplements do not adversely affect the breast tissue of postmenopausal women.4
  • The World Cancer Research Fund International concluded there is a possible link between soy intake and improved survival from breast cancer

Thyroid function

  • Clinical studies show neither soy foods nor isoflavone supplements adversely affect thyroid function in healthy individuals with a normal functioning thyroid even when exposure occurs over several years and greatly exceeds typical Japanese intake.
  • After a multi-year evaluation the European Food Safety Authority concluded that isoflavones do not adversely affect thyroid function in postmenopausal women.4
  • Also, soy foods are not contraindicated for hypothyroid patients


  • Clinical studies show soy does not prevent ovulation or appreciably affect reproductive hormones in premenopausal women.
  • Epidemiologic data suggest soy intake may negate the harmful effects of BPA on live birth rates in women undergoing assisted reproductive technology.
  • In men, clinical studies show neither soy nor isoflavones affect sperm or semen parameters and epidemiologic data show male soy intake doesn’t affect in vitro fertilization rates in their partners.

Overall it can be concluded that the overwhelming amount of evidence from clinical and epidemiologic studies refute any concerns about the use of SOY in DAILY diets and directly supports the safety and potential benefits of soy consumption.

In addition, vegans and vegetarians, as well as those following non-vegetarian diets have an important, safe and tasty alternative to animal protein, in the form of the humble soy bean!

Soya Life products are available in the health section of Dischem stores and selected leading retail pharmacies countrywide. Look out for our new packaging – Soya Life One Way! We now offer a more robust 1 kg Breakfast Porridge box. Find out more.

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