Soy Beans & Breast Cancer

Soy is an edible crop of Asian origin. It is the most common source of plant protein and vegetable oils. In recent years, soy has been evaluated in clinical trails in the prevention and treatment of hormone-dependent breast cancer. However, scientists argue as to whether soy prevents or promotes breast cancer. It would be a good idea to speak with your doctor before you decide to add large amounts of soy to your diet.

Soy Composition

Soy adequately provides all nine essential amino acids that are the main building blocks of protein. Essential amino acids cannot be manufactured in your body, so you must obtain them from soy and other foods. Soy is also rich in essential fatty acids, such as linoleic and linolenic acids, but contains no saturated fats and cholesterol. The non-nutritive compounds found in soy include isoflavones, saponins and phytosterols.

Estrogen-Dependent Breast Cancer

Breast cancer is a malignant tumor found in the breast. It is the most common form of cancer among women in the United States, according to Cedars-Sinai Medical Center. Breast cancer occurs as a result of harmful mutations in the genes responsible for regulating the growth of cells in the breast. Invasive breast cancer can attack and destroy nearby healthy tissues and spread throughout the body via the bloodstream or lymph system.

Negative Effects of Soy on Breast Cancer

Soy contains substances called isoflavones. These plant molecules resemble the natural female sex hormone estrogen in structure. Hence, soy isoflavones can bind to estrogen receptors and exhibit estrogen-like effects. It is likely that soy isoflavones strengthen the body's natural estrogen. It is generally agreed that some breast cancers only grow in the presence of the female hormone estrogen, according to a 2010 study at the University of Southern California.

Positive Effects of Soy Estrogens on Breast Cancer

Proponents of soy argue that soy isoflavones are weak forms of estrogens in the human body. Being a weak form of estrogen, isoflavones can interfere with the body's own estrogen in the regulation of breast tissue development, the most common pathway for breast cancer, according to a 2010 study at the University at Buffalo and Roswell Park Cancer Center.