Milk vs. Soy Milk — Health Impact and Nutrition Comparison

Price

Milk is cheaper than soy milk and is more commonly available than soy milk. 

Taste and Flavor

The taste of milk is often derived from its fat content and what the cow is consuming. The higher the fat content, the denser and stronger the flavor. Cows often graze grass in summer, and the milk has a more robust taste and a more creamy color than white. That is due to a higher beta-carotene and vitamin A content. 

In comparison, soy milk has an earthier flavor and is not as creamy. Its taste can easily overwhelm other associated foods. 

Culinary Usage

Milk is frequently used in different cuisines. It is one of the most fundamental food elements because we process milk to produce cheese, butter, cream, and yogurt. In addition, milk is often used in different cuisines worldwide. Soy milk is more limited in use than milk.  

Powdered milk is also often used instead of formula-fortified milk to replace breastfeeding. Its advantage is that it has a higher shelf life.

Powdered milk and milk have different nutrition, taste, and health peculiarities.

Calories

Low-fat milk and soy milk have similar calories. Although a slight difference exists, it's not very relevant. Milk has 42 calories, and soymilk has 54 calories. 

Carbs

The carbohydrate distribution of both is quite different. One of the main differences is the presence of lactose. 

Soymilk does not contain lactose, whereas milk contains lactose.

Soymilk contains 6.3g of carbs, slightly higher than milk, which contains 4g of carbs. 

Fiber

Since soymilk is derived from soybeans, it contains a small amount of fiber, about 0.6g per 100g. Milk, an animal-derived food product, does not contain fiber. 

Glycemic Index

The glycemic index of milk is 31, whereas the glycemic index of soymilk is 37.

Milk has a lower glycemic index than soymilk. 

Protein

The protein distribution of soy and milk is also different in their types. 

Dairy milk contains whey protein and casein protein, and soy protein is a its own. The amino acid profile and the type of digestion are different. 

Milk has more essential amino acids and is considered a higher quality protein than soy milk. 

Fats

Although soy milk contains higher amounts of total fats, the distribution of types of fats is essential to consider. This is because milk contains higher amounts of saturated fat. However, this low-fat amount is insignificant and won't cause health issues since it's about 0.6g. 

In short, soy milk is richer in polyunsaturated and monounsaturated fats. 

Cholesterol

Soy milk does not contain cholesterol, whereas milk contains 5mg. For a deep dive into the effect of milk cholesterol on health, check the health section regarding cardiovascular health.  

Macronutrient Comparison

Macronutrient breakdown side-by-side comparison

Milk

3

:

2

Soy milk

Contains more Other +15.4%

Contains more Fats +80.4%

Contains more Carbs +25.9%

Equal in Protein - 3.27

Equal in Water - 88.05

Milk

Protein: 3.37 g

Fats: 0.97 g

Carbs: 4.99 g

Water: 89.92 g

Other: 0.75 g

Soy milk

Protein: 3.27 g

Fats: 1.75 g

Carbs: 6.28 g

Water: 88.05 g

Other: 0.65 g

Contains more Other +15.4%

Contains more Fats +80.4%

Contains more Carbs +25.9%

Equal in Protein - 3.27

Equal in Water - 88.05

Minerals

Milk is richer in calcium, phosphorus, potassium, and zinc. In comparison, soy milk is richer in selenium, manganese, copper, magnesium, and iron. 

This infographic showcases the distribution of minerals in both milk and soy milk. 

Mineral Comparison

Mineral comparison score is based on the number of minerals by which one or the other food is richer. The "coverage" charts below show how much of the daily needs can be covered by 300 grams of the food.

Milk

5

:

5

Soy milk

Contains more Calcium +400%

Contains more Phosphorus +82.7%

Contains more Potassium +27.1%

Contains less Sodium -13.7%

Contains more Zinc +250%

Contains more Iron +2033.3%

Contains more Magnesium +127.3%

Contains more Copper +1180%

Contains more Manganese +7333.3%

Contains more Selenium +45.5%

Milk

Soy milk

Contains more Calcium +400%

Contains more Phosphorus +82.7%

Contains more Potassium +27.1%

Contains less Sodium -13.7%

Contains more Zinc +250%

Contains more Iron +2033.3%

Contains more Magnesium +127.3%

Contains more Copper +1180%

Contains more Manganese +7333.3%

Contains more Selenium +45.5%

Oxalates

Milk does not contain oxalate, and soy milk contains negligible amounts. Yet it is essential to note that oxalate is often combined with calcium in the digestive system, and both are not absorbed. 

This is a double-edged sword for us. At first, oxalate is bound to calcium and not absorbed as an advantage because the kidneys would excrete excess oxalate, which can cause calcium oxalate urinary stones. 

And the negative aspect of this is that we are not absorbing calcium as a nutrient.  

If you want to know how to reduce the oxalate content of food, various methods can help you reduce your oxalate intake.

Vitamins 

Often, milk and soy milk are fortified with different minerals, mainly vitamin A and vitamin D. This is done to prevent deficiencies in these vitamins within a population. 

Thus, milk is richer in vitamin A, vitamin D, vitamin B2, and vitamin B12. In comparison, soy milk is richer in vitamins B1, B6, and folate. They have similar amounts of vitamin B5. 

The infographic below shows vitamin distribution in milk and soy milk. 

Vitamin Comparison

Vitamin comparison score is based on the number of vitamins by which one or the other food is richer. The "coverage" charts below show how much of the daily needs can be covered by 300 grams of the food.

Milk

4

:

7

Soy milk

Contains more Vitamin A +6433.3%

Contains more Vitamin D +∞%

Contains more Vitamin B2 +168.1%

Contains more Vitamin B12 +∞%

Contains more Vitamin E +1000%

Contains more Vitamin B1 +200%

Contains more Vitamin B3 +451.6%

Contains more Vitamin B6 +108.1%

Contains more Folate +260%

Contains more Vitamin K +2900%

Equal in Vitamin B5 - 0.373

Milk

Soy milk

Contains more Vitamin A +6433.3%

Contains more Vitamin D +∞%

Contains more Vitamin B2 +168.1%

Contains more Vitamin B12 +∞%

Contains more Vitamin E +1000%

Contains more Vitamin B1 +200%

Contains more Vitamin B3 +451.6%

Contains more Vitamin B6 +108.1%

Contains more Folate +260%

Contains more Vitamin K +2900%

Equal in Vitamin B5 - 0.373

Milk Substitutes 

Different milk substitutes are suitable for different diets, such as vegan, vegetarian, and lactose-intolerant diets. Soy milk is one of the main alternatives. 

Cardiovascular Health 

Often, milk gets a bad reputation by claims such as "it increases blood cholesterol levels, LDL cholesterol levels, and triglyceride levels." However, these claims are not supported by scientific evidence. Scientific evidence indicates that milk consumption, even 0.5L/day, had no significant impact on blood lipid levels (1).  

There are no negative impacts for individuals who don't have any blood lipid disturbances and are not consuming the higher calories needed for the body, including milk, in their diet. Interestingly, consuming full-fat milk compared to low-fat milk showed increased HDL cholesterol levels, which has a positive impact (2).  

Above all this, only half of our dietary cholesterol is absorbed, so if you consume one glass (250ml) of milk containing 12.5mg of cholesterol, you absorb roughly 7mg of this cholesterol. 7mg of an upper limit of consumption of 300mg (3). 

When it comes to soy milk, the risks of overall cardiovascular disease have decreased when consumed. 

Overall, soy milk is beneficial for cardiovascular health since it decreases the risks of cardiovascular diseases. In comparison, milk has a neutral association when consumed in moderate amounts.

Inflammation 

Dairy products, especially milk, are accused of being pro-inflammatory, and no one knows why. With an influx of "influencers" on social media, any claim can be made without demanding the source, but the scientific method does not work that way. 

According to numerous research publications, there was no association between a proinflammatory state and consumption of milk. 

This data was reproduced in individuals with and without metabolic diseases (4). 

Soy milk contains isoflavones such as genistein and daidzein, which have anti-inflammatory properties. These isoflavones decreased CRP (C-reactive protein), an inflammatory marker (5). 

Digestive Tract Health

Milk consumption is often associated with bloating and flatulence despite not being lactose intolerant. This falls under "milk-related gastrointestinal discomfort"; one explanation is the difference in gut microbiomes. Less efficient digestion of milk proteins can more often lead to discomfort symptoms (6).

A more severe form of milk-related gastrointestinal affection is lactose intolerance. When our gastrointestinal cells don't produce lactase, the enzyme that breaks down lactose into simpler sugars, we often have symptoms such as bloating, diarrhea, and flatulence (7).

Lactose-intolerant individuals can consume soy milk since it does not contain lactose in its carbohydrate composition.  

Soy milk improves overall gastrointestinal microbiota and reduces inflammation, especially in ulcerative colitis patients. Thus, soy milk can benefit gastrointestinal health more (8).  

Impacts of Antibiotics and Heavy Metals on Health 

One of the significant public health concerns nowadays is antibiotic usage in the livestock industry. Several antibiotic residues are found in mass-produced milk, which must be addressed appropriately to prevent any problems arising from irresponsible and excessive antibiotic use (9).  

When it comes to heavy metals, soy milk is also a concern because it has higher cadmium and manganese levels (10). 

Diabetes

There is no association between type 2 diabetes and milk consumption. An inverse association shows decreased risks of developing type 2 diabetes Mellitus with low-fat milk consumption (11).

Similarly, soy also showcased an inverse association with type 2 diabetes mellitus (12). 

Hormones

Soy milk contains phytoestrogens that are thought to affect male hormone levels. However, meta-analysis results showed that consumption of soy milk and isoflavones in soy did not affect hormone levels in males. The hormones that were measured during this study were:

• Total testosterone
• Free testosterone
• Estrone (E1) 
• Estradiol (E2) 

Soy milk is safe to consume and will not affect male hormone levels (13). 

Cancer

There is a controversy around cancer and milk consumption; however, a meta-analysis showed that when comparing milk and soy milk with the incidence of cancer, milk had a higher incidence risk of developing breast cancer. Yet, further research must be indicated to understand the mechanism (14).  

Milk consumption is also positively linked with the development of estrogen-positive breast cancer. This mechanism is linked with microplastics and the induction of hormones such as IGF-1 insulin-like growth factor (15).