The Soy Story

Soybeans and their products have been part of the Asian diet for centuries. Tofu (the soybean curd) originated in China and is a key protein source in the Asian diet. However, until as recently as 40 years ago they were virtually unheard of in North America. Soybeans and their products - items that used to be sold to vegetarians only - are now widely available and accepted as part of a healthy diet.

Nutritional value

Unlike most vegetable proteins, soybeans are a source of high quality protein. Soybeans also contain the essential fatty acids linoleic and linolenic, B vitamins and minerals (including zinc, iron and, if processed with calcium, a source of calcium). Phytoestrogens (i.e. isoflavones) found in soybeans are weak estrogen-like substances that can exert hormone activity as well as antioxidant effects. It is these properties that make soy so interesting. Also, soybeans contain no saturated fat; the type of fat known to raise blood cholesterol levels. Soy products including soy cheese and fortified soy "milk" do not contain lactose and, providing they are fortified with calcium, vitamin D and vitamin B12, make an excellent alternative to cow's milk.

Soy protein is also easy to cook with and is less expensive than other protein foods.

Health Benefits

Heart Health

The heart health benefits of soy have been well documented. Including soy foods in the diet has been shown to lower blood cholesterol and to protect the blood from clotting. The phytoestrogens found in soybeans (i.e. isoflavones) have antioxidant effects. Antioxidants protect LDL cholesterol (the "lousy" or "bad" cholesterol) from oxidative damage preserving the arterial walls. In people who start out with high LDL cholesterol levels, 25 grams per day of soy protein is enough to lower LDL cholesterol by about 10%. In addition, one particular isoflavone, genestein, has been shown to increase the flexibility of blood vessels, which improves blood flow, and decreases blood pressure.

Women's Health

Because isoflavones are thought to help to preserve estrogen levels in the body, the inclusion of soy products has several implications to women's health.

Bone Health

A new area of research has shown that including soy products in the diet may prevent or reduce the bone loss associated with aging.

Menopausal Health

Some researchers have found that soy products may have the effect of reducing some of the symptoms associated with menopause, namely hot flashes and night sweats.

Cancer Prevention

Soy foods, rich in isoflavones may protect against endometrial (lining of the uterus), breast and other hormone related cancers (e.g. ovarian) but the data is conflicting. Many experts agree that soy foods are health protective for all women, however, some research raises concern about isoflavone supplements (sold as soy protein isolates or isoflavones).

Men's Health

The isoflavones found in soy products are thought to interfere with cancer of the prostate by inhibiting testosterone from turning into a form that promotes cell growth, therefore, they may decrease the risk of prostate cancer.

Soy Products at your Thrifty Foods

The following soy products can be found at your local Thrifty Foods:

  • Fortified soy beverages
  • Soy cheese product
  • Soy yogurt
  • Various types of tofu (from soft or dessert to firm and extra firm)
  • Textured vegetable protein, TVP (from the bulk food section)
  • Meatless "meats" and patties such as Yves 'Veggie Ground Round' or "turkey slices"
  • Tempheh
  • Miso (soy paste)
  • Soy flour
  • Soybean oil

If you are having trouble finding soy products, ask any customer service representative to assist you.

Using Soy Products - The options are endless if you keep an open mind!

When you are starting out, try to include two servings of soy products each week.

The top 10 ways to incorporate soy foods into your diet:

  1. Blend soft tofu or soy yogurt with fruit, juice, and ice cubes in a blender for a terrific breakfast shake.
  2. Add firm tofu to a stir-fry. Just brown it in sesame oil and add to your veggies.
  3. Substitute soy beverages for milk - soy beverages come in a variety of flavors such as vanilla, strawberry, chocolate and plain.
  4. Crumble Yves Veggie Ground Round into spaghetti sauce.
  5. Try a soy-based burger or veggie dog for a change.
  6. Snack on a small handful of roasted soy nuts.
  7. Use pureed tofu for dips or creamy salad dressings.
  8. Make a bean salad - use soybeans for added texture and variety.
  9. Use texturized vegetable protein to "extend" the meat in chili.
  10. Visit your local library for a vegetarian cookbook and try recipes that use soy or tofu.

Serving Sizes

Soy products fit perfectly into Canada's Food Guide to Healthy Eating. The following servings are equivalent to one serving as outlined by Canada's Food Guide. Aim to include 2 servings a week to start.

1/3 cup tofu (any texture - soft to extra firm)

1 cup fortified soy beverage

1 1/2 ounces (50g) of soy cheese

3/4 cup soy yogurt

Food Safety

Tofu and other perishable soy products should be stored in the refrigerator and used within one week of opening. Soy products can be frozen but freezing changes the texture of the final product. If you do freeze tofu, squeeze the excess water out of it after thawing then cube or crumble before using.

Pregnancy

The consumption of soy products in pregnancy is considered safe.

Soy Infant Formula

If breastfeeding is not chosen or possible, the next best choice is a commercial iron fortified infant formula. There are two basic types of routine infant formulas found on the shelves: cow's milk-based and soy-based. Some parents choose to offer soy-based formula to their infants for cultural or ethical reasons. For these reasons, iron fortified soy-based formulas are a good alternative.

Although soy based infant formulas are lactose free, they are not recommended for the long-term management of "fussy" or "colicky" infants. Before switching from breast milk to formula or from cow's milk based formula to soy formula consult your local Community Nutritionist public health nurse.

Safety concerns regarding commercial soy infant formula

Infants fed soy formula have higher levels of isoflavones in their blood compared to those infants fed cow's milk formula or breast milk. Although extensive research is lacking in this area, babies have been fed soy formulas for over 40 years with no apparent harm. Occasionally, you may hear about the concern regarding aluminum levels in soy formulas for infants. Although the aluminum levels in soy formulas are significantly higher than in other infant formulas, they are well below those levels considered harmful.

Contact your local health unit to speak to the Community Nutritionist or public health nurse if you have further questions regarding the use of infant formulas.

The Bottom Line - Safety

The heart benefits of soy are well documented and many experts agree that soy foods are health protective, however, some research raises concern about isoflavone supplements/pills (soy isolates) and women who have a family history of hormone related cancers. Since the safety of concentrated isoflavones, or soy isolates, has not been well studied more research is need in this area for a definitive recommendation to be made.

To keep it safe:

  • If you already include soy products in your diet continue to do so
  • Avoid soy supplements if you are allergic to soy
  • If you are interested in including soy products in part of a healthy diet, consider adding up to 2 servings each day (see above for serving sizes)
  • If you have breast, ovarian, cervical or other hormone related cancer and wish to start eating soy products, talk to your doctor or dietitian where you are receiving treatment. This is especially true for women with breast cancer, as some studies have shown that isoflavones may actually encourage breast tumor growth