Soy
We often hear that consuming soy products is bad for you because it can increase the risk of cancer, specifically breast and prostate cancer. This rationale was determined because of the many trials conducted on animals that resulted in isoflavones (plant-based compounds that mimic Estrogen) being identified as the culprit that increased the risk of breast cancer. More research has been conducted with results demonstrating that isoflavones are metabolized differently in animals and humans. In humans, isoflavones attach to estrogen receptors in the body ultimately suppressing the growth of the tumor cell.
Does this mean I can just take soy supplements instead of consuming foods like edamame, tofu, soy milk, or soy sauce? Not necessarily. Just like any type of food, consuming the food in its whole, natural form is the best way to get all the nutrients available. For instance, whole soybean products like tofu and edamame are excellent sources of protein, iron, B vitamins, and fiber. Consuming soybean products can decrease the risk for coronary heart disease and assist with bone health, hot flashes, and blood pressure in menopausal women.
It is important to mention when discussing soybeans that they are one of the major food allergens. Soy allergies are often common in babies and children therefore be aware of any allergic symptoms after consumption. Allergies could be in the form of itching, tingling sensations in the mouth and around the lips, wheezing, shortness of breath, and even hives. If you experience any of these symptoms, contact your doctor immediately and read the nutrition labels of every item purchased. Major food allergens are listed in the ingredients with the allergy in parenthesis OR under the ingredient list in a “contains” statement.
Diary
On the other hand, the intake of dairy has also been a highly debated topic with regards to whether it increases the risk of cancer. However, research has shown there is limited evidence proving that a cancer patient consuming a large serving of dairy products will do more harm. Dairy intake is important for the consumption and absorption of calcium to help maintain strong bones. Everybody should strive to have strong bones to prevent falls and fractures in older age. Cancer patients receiving radiation should be especially in tune to daily intake as radiation can result in weakened bones. Below lists the recommended daily calcium based on age and gender:
| Age | Male | Female |
| 14-18 years | 1,300 mg | 1,300 mg |
| 19-50 years | 1,000 mg | 1,000 mg |
| 51-70 years | 1,000 mg | 1,200 mg |
| >70+ years | 1,200 mg | 1,200 mg |
*Note that those with prostate cancer need to keep daily calcium intake under 1500 mg/day*
There have also been studies that have shown that dairy intake can decrease the risk of colorectal cancers. In studies, calcium has been shown to kill the cells associated with colorectal cancer. Regarding colorectal cancer, calcium, vitamin D, and the lactic acid found in the dairy products would help protect the patient. Dairy has also been shown to prevent osteoporosis, hypertension, type 2 diabetes, and even metabolic syndrome.
With any cancer, there is the potential for the patient to experience weight loss. Having a good diet with adequate protein and calories is essential for the patient undergoing cancer treatment. Dairy products are a great source to help patients get adequate calories and protein during cancer treatment. Adding cheese to potatoes or broccoli, drinking milk shakes or simply string cheese are examples of how to incorporate dairy into the diet. If eating whole meals is hard for patients, eating small meals and snacking on high protein foods are ideal. Yogurt, a sandwich with cheese, crackers and cheese or even a small bowl of cereal can help with the intake of dairy and achieving a high protein meal.
Depending on treatment and calories needed for the patient, a simple breakfast could be a bowl of cereal (milk or soymilk) and apple slices with peanut butter or pancakes and apple slices with cheese. Throughout the day snacking on nuts or edamame, yogurt with chia seeds, and even pudding or drinking a nutritional supplement such as Boost™ or Ensure™ can help increase calories and high protein content needed to build and maintain the integrity of the body. Below is a list of different soy and dairy products along with some nutrition information:
| Food Item | Serving Size | Calorie | Protein (g) | Sodium (mg) | Cholesterol (mg) |
| Soy milk | 1 cup | 131 | 8 | 124 | 0 |
| Cow’s milk (1%) | 1 cup | 103 | 8 | 12 | 12 |
| Tofu | 0.5 cup | 94 | 10 | 9 | 0 |
| Yogurt (plain, Greek, nonfat) | 6 oz | 100 | 17 | 61 | 9 |
| Edamame | 1 cup | 189 | 17 | 9 | 0 |
The Bottom Line
The intake of soy and dairy products by cancer patients have a long history of being misunderstood. With more research and thorough understanding of how soy and dairy products are metabolized in the body, they are now welcomed with open arms as part of a patient’s daily intake. Both food items protect and lower the risk of cancer in patients in their own way. It is important that patients listen to their medical staff especially their physicians and dietitians when it comes to matters of rebuilding their bodies making them stronger and healthier. So, remember, eat edamame as an appetizer, try soymilk if there is a lactate intolerance, and enjoy your dairy products.
