According to a 2009 article published in "USA Today," it is estimated that 60 per cent of the adult population worldwide cannot digest cow's milk. Soy milk and its light variety have become popular alternatives, the latter being a favourite among dieters. However, there is research to suggest there are various side effects associated with soy milk.
Soya beans, from which both regular and light soy milk are derived, contain high levels of phytic acid, which prevents the normal absorption of many minerals such as magnesium and iron. In countries where soy is part of the daily diet (e.g., Japan), consumers also eat fish and meat, from which they still obtain the necessary minerals to maintain a balanced diet. Vegans in particular, who consume light soy milk as an alternative to dairy, risk becoming mineral-deficient.
Dangers of Diluting Soy Milk
Light soy milk contains less protein than regular soy milk. This is because some protein is lost when extracting it, and many companies add water to dilute it. According to health practitioner Dr. Ben Kim, some brands of light soy milk use sweeteners to make up for the loss of flavour which occurs when it is watered down. Sweeteners, whether natural or not, are a burden on the pancreas and liver, and can raise insulin levels, resulting in side effects such as increased blood pressure, weight gain and heart problems.
Certain light soy milk manufacturers use soy flour rather than soya beans. Soy flour is made with a chemical called hexane, which is a byproduct of gasoline and is highly explosive. It is possible to make soy flour without using hexane, although processing with the chemical is cheaper. While the long-term side effects of consuming hexane have not been thoroughly studied, the Environmental Protection Agency has listed it as a "hazardous air pollutant."
Side Effects in Children
Light soy milk contains substances labelled "anti-nutrients" by scientists, which depress the thyroid gland, slowing down growth. In foods where the soya beans have undergone a process of fermentation (tofu, for instance), this does not occur, as fermentation gets rid of growth inhibitors such as hemagglutinin---however, this is not the case with milk products. A study conducted by J. Joseph Rackis entitled "The USDA Trypsin Inhibitor Study" showed that when young rats were fed soy containing growth inhibitors, they didn't grow at the same rate as rats on a diet without soy. Hemagglutinin also causes red blood cells to clump together, clotting the blood.