Soy - Uses, Benefits, Side Effects, and More

Table of Content

• What is Soy?

• Is soy healthy?

• Soybean nutritional profile

• 8 Benefits of eating soy

• Bone Health and Soy

• How much soy is safe per day?

• Soy side effects in females

• Soy side effects in males

• Side effects of eating too much soy

• Take-Home Points

• FAQ on Soy

Introduction

One of the trending lifestyle food components is soy, because of its numerous health benefits and the tremendous amount of protein compared to other vegetarian food options. Despite the nutritional profile, soy is not suitable for everyone. Let’s understand more about soy.

What is Soy?

It is a legume native to East Asian countries like China, Japan, and North and South Korea. It is one of the traditional foods in Asian cuisine. India contributes to 3% of worldwide soy production, whereas Italy is the largest producer with 9 lakh tons of soybean every year.

Traditionally it is consumed in the form of soy milk, tofu, soy sauce, and fermented soybean pasta, as a cheap and ready-to-eat source of protein.

Recently soy consumption has increased due to the adaptation to a vegetarian lifestyle. It is one of the best nutrition sources for vegetarians.

Is soy healthy?

Yes, soy is the nutritious food analog to milk, its protein quality is similar to cow milk and egg protein. It has a variety of components that benefit in several ways.

It is rich in saponin, phytic acid, and isoflavones. As compared to other dietary foods, soy is a uniquely rich source of isoflavones, it is a major component known as phytoestrogen and has estrogen-like properties hence soy is referred to as weak estrogen. Isoflavones are linked with numerous health benefits.

Soybean nutritional profile

• Energy: 446 kcal

• Unsaturated fatty acids: 4g

• Carbohydrates: 30g

• Fat: 19g

• Protein: 36g

• Fibre: 9g

• Sugar: 7g

• water: 8g

• Iron: 15mg

• Calcium: 277 mg

• Potassium: 1800g

• phosphorous: 704g

• magnesium: 280g

• Vitamin C: 6g

• Iron: 15g

• Zinc: 4mg

8 Benefits of Eating Soy

1. Diabetic-friendly

 It has low carbohydrate content hence so do the traditional Asian soyfood dishes which makes them diabetic-friendly. The carbs get slowly digested which enhances the bacterial growth in the gut, therefore soy is a good prebiotic too.

2. Good iron absorption

As opposed to the poor absorption of iron in all plant food, iron absorption from soy is good because of the presence of ferritin (absorbable iron form).

3. Improve skin health

It is not surprising that soy benefits our skin as it binds to estrogen receptors and improves skin elasticity, water-holding capacity, and pigmentation.

4. Reduces risk of kidney diseases

Though with high protein concentration, it does not stress the kidneys like other protein-rich foods. Hence it potentially reduces the risk of renal disease.

5. Improve heart health

 In cardiovascular diseases, one of the complications is the dysfunctioning of heart wall linings, this is improved by the isoflavones of soy. Soy helps in vasodilation; this is effective for women with specific postmenopausal heart diseases.

6. Decreases risk of breast cancer

It is recognized that breast cancer incidences are very low in the population consuming soy food. It is concluded that consuming soy in the adolescent phase only is associated with breast cancer protective actions. Soy consumption also plays a role in the improvement and prognosis of breast cancer.

7. Decreases risk of prostate cancer

It is the 2nd most common cancer in men worldwide. Similar to breast cancer Asians show a 50% reduction in prostate cancer risk due to high consumption of soy food.

8. Improve blood flow

The isoflavones help to reduce the artery’s stiffness in postmenopausal women. Promote unrestricted blood flow.

Bone Health and Soy

It is a controversial topic as more research is required here. 2 Asian epidemiologists have concluded that soy consumption is associated with a 1/3 reduction in bone fracture risks. One study concluded mixed results because of unfavorable long-term effects on calcium profile.

Therefore, whether the effect of eating soy on calcium levels is favorable or unfavorable is still a puzzle. It needs more research and studies.

How much soy is safe per day?

The FDA says 25 g/day of soy protein is the threshold intake for cholesterol reduction. Twenty-five g is certainly more soy protein than is consumed by most Asians, by a combination of the soyfoods this threshold value can be achieved.

Soy side effects in females

Due to menopause and increasing age women develop obesity, postmenopause symptoms, and other health-related problems. Hormonal fluctuation leads to an increase in adipose tissue concentration which leads to water loss and obesity. 

Notably, phytoestrogen (estrogen-like structure, important and abundant

chemical constituent) is used as a natural alternative to estrogens for hormone replacement therapy in menopause. Phytoestrogen has shown protective action against menopausal osteoporosis. 

Despite having beneficial health effects soy has numerous side effects in females –

1. Allergy: Soy is an allergic food for some people just like peanuts.

2. Cholestasis: Soybean oil is one of the major causes of cholestasis (Reduced flow of bile in the liver due to infection, and gallstones).

3. May alter fertility: There is a possible adverse impact of soy on the fertility rate in Asians who were traditionally consuming soy. This is because of excessive intake or differences in isoflavones.

4. Increased menstrual cycle length: The intake of soy is linked inversely with the blood estrogen levels which increased menstrual cycle length. This is a concerned side effect of soy in females.

5. Worsen the thyroid: Soy foods inhibit the absorption of iodine and it seems that soy food may increase the risk of hypothyroidism. In this case, consult your doctor about the condition.  

Thyroid diseases are more common in postmenopausal, and eating soy will increase the side effects in females.

Soy side effects in males

Modest consumption of soy is associated with lower sperm concentration due to increased ejaculation in men consuming a higher amount of soy.

All combined three studies concluded that isoflavones in soy have no effect on sperm concentration or quality of sperm.

Bottom line- Consuming an excess amount of any food can potentially lead to some abnormalities in your body. Keep it simple and proportionate.  

Side effects of eating too much soy

Soy is one of the nutritious and safe foods when consumed in moderation.

1.  Most common side effects are indigestion, constipation, and diarrhea.

2.  Alter the absorption of iodine in thyroid patients.

3.  Soy helps in bone health, although strong evidence is not available, in some studies have shown decreased calcium levels.

4.  It is not a good food option during pregnancy. Eat it in moderation with a doctor’s consultation.

Take-Home Points

• Soy is one of the best sources of protein for vegetarians. With changing lifestyles, soy consumption is increasing worldwide.

• Eating soy in moderation provides you with a lot of benefits and preventative measures.

• Soy has no side effects on men as per the documented research and studies.

• It has the potential to reduce breast cancer and also helps in the prognosis of breast cancer. 

• Soy milk, tofu, and hemp provide the same amount of nutrition.