Soy vs. dairy milk: which is better for you?

Proponents of soy milk tout it as a natural, plant-based source of protein and point to research that shows that soy milk lowers LDL (low density lipoprotein), or “bad” cholesterol in the body, thereby cutting a person’s risk of developing heart diseases. Soy critics argue that soy contains phytoestrogens, which are thought to interfere with a child’s development.

How do you, as a consumer, make an informed choice? To help you, we discuss here some important questions about soy and cow’s milk, namely:

  1. What is the difference between soy and cow’s milk?
  2. Should people with gout avoid soy?
  3. Is soy or dairy better for patients with cancer?

What is the difference between soy milk and cow’s milk?

Soy is a good source of low-fat and plant-based protein. It is cholesterol-free, has less saturated fat than cow’s milk and lowers the LDL in the body. Cow’s milk, on the other hand, has more calcium than natural soy. Calcium, as we know, helps to build bones and prevents osteoporosis. Cow’s milk also contains more vitamins, such as vitamin B12 and vitamin D.

These days, however, commercially made soy milk is often fortified to have calcium and nutrients similar to cow’s milk. At the same time, cow’s milk now comes in low-fat versions and these sometimes have lower saturated fat than commercial soy milk (see table below).

Both calcium-fortified soy milk and low-fat milk are good sources of protein and calcium. "However, there is evidence that soy products, together with a diet low in​ saturated fat, can help to lower LDL level, and hence reduce the risk of heart disease," says Ms Christine Ong, Senior Principal Dietitian from the Nutrition and Dietetics Department at KK Women's and Children's Hospital (KKH), a member of the SingHealth​ group.

Nutrient​Soy milk (250ml)Milk (250ml)
 NaturalFortified (hi-calcium, reduced sugar)Full creamHi-calcium, low fat
Energy (kcal)138143150

110

Protein (g)71088.8
Fat (g)43.88.12.5
^ Saturated fat (g)^ 0.7^ 1^ 4.7^ 1
Cholesterol (mg)00256.3
Calcium (mg)25450282375

Should people with gout avoid soy?

Many people think that if you suffer from gout, you should not eat any soy. This is not totally true. Gout is due to excessive uric acid in the blood, which causes crystal deposits to form in the joints, leading to inflammation and pain. Uric acid is derived from purine, which is found in protein-containing foods such as soy.

If you suffer from gout, it is important to lose weight if you are overweight. Drink adequate fluids; restrict alcohol intake and refrain from eating large meals. As for food, you should avoid fatty foods and foods which are high in purine. Foods like soy, which are moderate in purine, can be consumed in moderate amounts as part of a healthy and balanced diet.

Food GroupLow PurineModerate PurineHigh Purine
Rice & alternatives:White rice, refined bread, cerealsBrown rice, wheat bran, oats-
Vegetables:Most vegetablesMushrooms, peas, spinach, asparagus, cauliflower-
Fruit:All fruit and juices--
Meat & alternatives(limit to 2 servings per day):Milk & dairy productsFish, chicken, bean, soy products, nuts, eggsLiver, organ meat, sardines, herring, mackerel, ikan bilis (dried anchovies), scallops
Seasoning:-Baker's & brewer's yeast, VegemiteMeat extracts, stock cubes

Are soy or dairy products better for cancer patients?

Some people think that because soy is plant-based, it is better for cancer patients. Dairy products are thought to “feed” cancer cells. There is no scientific evidence to prove this theory. Cancer patients in general need a high-energy and high-protein diet. Both soy and dairy products are good sources of protein and should benefit a patient undergoing cancer treatment. However, women with estrogen receptor-positive breast cancer should avoid soy supplements and not eat excessive amount of soy products.

Ref: W09​