If you can't digest lactose but still want to pour some type of beverage on your morning cereal, you might find yourself scouring the alternative dairy shelves. Both lactose-free milk and soy milk can provide liquid substitutes for regular cow's milk, but their benefits, drawbacks and nutritional value vary considerably. Lactose-free milk is made from cow's milk with the lactose removed, while soy milk is made with liquid from the soy plant and isn't, technically, milk at all.
More than 30 million Americans have lactose intolerance, according to MedlinePlus. If you are among them, either soy milk or lactose-free milk might hit the spot. Intestines absorb lactose, the main sugar in milk, by producing the enzyme lactase, which breaks down the sugar. If you are lactose intolerant, consuming lactose gives you gas, diarrhea and bloating, usually within 30 minutes to two hours after drinking it. Lactose-free milk has lactase added so you can digest the milk. Soy milk contains no lactose since it's made from soybeans, which are naturally lactose-free.
Cow's Milk Allergy
If you avoid cow's milk because of an allergy, drinking lactose-free milk won't help; it still contains the proteins that cause allergic symptoms in susceptible people. You might be able to drink soy milk, but soy is also a food with high allergenic potential. Ten percent of children with cow's milk allergy also had a soy allergy in a Finnish study, reported in February 2002 in "The Journal of Pediatrics." If you have a cow's milk allergy, approach soy milk cautiously, watching for signs of an allergic reaction. These include wheezing, rash, facial swelling, hives, nausea, vomiting, diarrhea, abdominal pain, weakness or passing out.
Lactose-free milk still contains the same amount of calcium, essential for bone growth, as regular milk. Soy milk has no natural calcium but manufacturers often add calcium to help consumers meet their daily calcium needs. However, the calcium in fortified soy milk is absorbed less effectively than the calcium in cow's milk; you absorb only about 75 percent as much calcium from soy, the Harvard School of Public Health warns. To offset this, choose soy milk with a higher amount of calcium than found in cow's milk. For example, a cup of skim milk contains 306 milligrams of calcium.
Protein and Fats
Soy milk and cow's milk have different nutritional values. Cow's milk contains saturated fat and protein; soy contains no cholesterol, very little fat and some protein. You can purchase low-fat, lactose-free cow's milk. In this case, you get the protein value without the saturated fats that can increase your risk of high cholesterol and atherosclerotic disease and can lead to heart disease. Soy's low fat content and full complement of essential amino acids might sway you toward giving it a try.
Articles For Your Diet
- Harvard School of Public Health: Calcium and Milk
- MedlinePlus: Lactose Intolerance
- The Journal of Pediatrics: Allergy to Soy Formula and to Extensively Hydrolyzed Whey Formula in Infants With Cow's Milk Allergy -- A Prospective, Randomized Study with a Follow-up to the Age of 2 Years
- The American Journal of Clinical Nutrition: Bioavailability of the Calcium in Fortified Soy Imitation Milk, With Some Observations on Method
- Harvard School of Public Health: Calcium Sources in Food
- The Journal of Perinatal Nutrition: Soy Protein
- Milk, milk and hands image by Mykola Velychko from Fotolia.com