Soybean Oil: How Good or How Bad in Comparison with Other Dietary Oils in the Context of Colon Cancer

Abstract

Soybeans (Glycine Max) are one of the oldest crops cultivated around the world, and in Asia soyfoods have been consumed for more than 1000 years. The soybean was popularized because of its high content of protein and good percentage of lipids. World consumption of soybeans in 2008 was over 221 million metric tons, with approximately 50% of this supply coming from US production, where over 77 million ha are planted annually. Soybeans are desired in the market as a source of protein and oil. Nowadays, soy has a huge economic importance because the beans are very versatile and can be used not only for human and animal nutrition but also for industrial products (Clemente & Cahoon 2009). Many beneficial effects of soy components such as soy protein, isoflavones, phytosterols, inositol hexaphosphate and saponins have been suggested, including the beneficial role for inhibition of tumor development in animal models (Hawrylewicz, Zapata et al. 1995). This has stimulated, in only the last 30 years, soybean introduction into western cultures and diets as different sub-products (Golbitz 1995). These products are usually fermented (tempeh, miso, soy sauces, natto, fermented tofu) or non-fermented (fresh soybeans, whole dry soybeans, soy nuts, soy sprouts, whole-fat soy flour, soymilk, tofu, soy protein, soy oil). One of the most used nonfermented subproduct is the soybean oil. The oil represents approximately 20% of the grain and is influenced by both genotype and environmental factors, and in some countries this is the main sub-product utilized in the diet (Clemente & Cahoon 2009). Soybean oil is a representative source of lipids in human nutrition. There are proposed mechanisms that explain lipids involvement in cancer development, especially colorectal cancer (CRC). Thus, comparing soybean oil composition with other oils is a discussion that is relevant in the context of CRC, once this is a public health concern.