Many vegetarians and vegans rely on tofu as their main source of protein, because it is inexpensive, versatile and convenient. Those who should avoid soy products, such as women undergoing breast cancer treatment, can derive protein from many other sources, even if they have ethical objections to or health concerns about eating meat and fish.
Estrogenic Effects of Soy
Phytoestrogens are organic chemicals that bind to the same cellular receptors as the female hormone estrogen. Although several hundred plant foods contain phytoestrogens, soy is one of the most significant dietary sources of a class known as isoflavonoid phytoestrogens. Scientific studies on the effects of soy show mixed results. Although it may have some cancer-preventive effects in moderate doses for most populations, it may potentially increase breast cancer risk, especially if consumed in large quantities, for certain women. Phytoestrogens also inhibit the effects of certain breast cancer treatments. If you have breast cancer, are at high risk or have had breast cancer in the past, consult your health care provider about consuming soy products, or avoid them.
Daily protein needs vary with gender. Adult men need at least 56 grams of protein and adult women at least 46 grams, although greater quantities are needed by lactating or pregnant women, people doing substantial amounts of resistance exercises or those with certain medical conditions.
Protein from Plants
Many nonanimal foods contain protein. Beans are the major protein source in many cuisines, containing 12 to 18 grams of protein per serving. Most grains contain 5 to 8 grams of protein in a serving, and certain vegetables such as mushrooms, spinach and broccoli may have up to 4 grams of protein per serving. Experiment with bean-based Indian or middle Eastern recipes for delicious protein-rich nonanimal meals.
Eggs and Dairy
Egg and dairy products can be consumed on their own or added to a variety of recipes to boost protein intake. A 50-gram large grade A egg has 6 g of protein. Dairy products, including cheese, milk and yogurt, provide 5 to 11 g of protein per serving. Mix nonfat dried milk or whey protein powder into smoothies for a quick and easy protein boost.
- BreastCancer.org: Soy
- Cornell University Sprecher Institute for Comparative Cancer Research: Phytoestrogens and Breast Cancer
- Vegetarian Resource Group: Protein in the Vegan Diet
- Alberta Egg Producers: All About Eggs
- Dairy Council of California: Nutrients in Milk
- Center for Disease Control and Prevention: Nutrition for Everyone, Protein l