NUTRITION Q&A
Soy milk vs. cow's milk
BY:HELEN RASMUSSEN, MS, RD, FADA
Q: I used to be able to drink milk but now it gives me gas and stomach cramps. Is soy milk a good alternative for those of us who cannot tolerate cow's milk?A: You have described a classic aging phenomenon when it comes to digesting milk. As we age, it is estimated that up to 80 percent of us stop making enough of the enzyme lactase to digest the milk sugar lactose. Symptoms of lactose intolerance include gas, diarrhea and nausea. A quick way to find out if you have lactose intolerance would be to try substituting an equivalent "symptom producing" amount with Lactaid "100" milk. This is milk in which 100 percent of the milk sugar lactose has been chemically digested by enzymes. After drinking this milk, you should remain symptom-free. Many individuals suffering from lactose intolerance either drink this enzyme-treated milk or take enzyme tablets before consuming milk or ice cream.
Soy milk is used as a substitute for cow's milk by many people, including individuals with lactose intolerance. Thus, soy milk, because it doesn't contain lactose, may be tolerated by those unable to drink cow's milk. It is made by mashing soybeans with water and looks a lot like cow's milk. If you do give up cow's milk, you are also giving up a very rich source of protein, calcium, B vitamins and vitamin D. Soy milk is comparable to cow's milk in good-quality protein, but unlike cow's milk, soy milk is not a good source of calcium (3 mg calcium per cup for soy, versus 300 mg calcium for skim milk), unless it is fortified with calcium. Some brands of soy milk are fortified with calcium to the level of cow's milk.
Soy milk is worth a try. However, some people also react adversely to the complex carbohydrates present in soybeans. There is some evidence that soy milk has fewer gastrointestinal effects than soybeans, but in some people soy milk can cause discomfort. As with cow's milk lactose-enzyme treatments, there is an over-the-counter therapy containing alpha-galactosidase, the enzyme that helps the gastrointestinal tract to digest bean carbohydrates (Beano) for individuals who need help digesting soy products.