The link, if any, between diabetes and cow's milk

Eating Well

September 10, 1996|By Colleen Pierre | Colleen Pierre,SPECIAL TO THE SUN

In recent years, cow's milk has been a suspected causative agent in childhood diabetes. Now, a study published recently in the Journal of the American Medical Association says it isn't so.

One out of every 300 U.S. children will develop insulin dependent diabetes, a chronic condition requiring daily injections of insulin and close supervision of eating and play, to be sure insulin and calories match up. Mismatches can result in hypoglycemia, unconsciousness or coma.

Despite great advances in improving the quality of insulin and methods of blood testing, as well as development of an insulin pump to replace injections, the disease results in shortened life expectancy and high rates of kidney disease, blindness and amputations.

So prevention is a high priority. And prevention demands a clear understanding of exactly what causes the disease.

It has long been known that diabetes has a genetic component, yet less than 5 percent of people with the diabetes gene develop the disease. So researchers have been looking for the "trigger" that sets the disease in motion in susceptible children.

This form of diabetes is an autoimmune disease where a body mistakes its own cells for foreign invaders. The pancreas' insulin-producing beta cells become the target of a search and destroy mission. When the mission is accomplished, the pancreas will never again produce insulin (although researchers are now attempting beta cell transplants).

This beta cell autoimmunity always occurs and is detectable before diabetes develops, usually before a child is 5 years old. Yet 80 percent of diabetes in children develops after age 5. So instead of focusing on milk-drinking and development of diabetes, the Diabetes Autoimmunity Study in the Young focused on the relationship between drinking cow's milk and developing beta cell autoimmunity.

The earlier focus has two important research advantages.

First, parents were interviewed about the child's early food consumption before he developed diabetes, which helps to cut down on recall bias. Recall bias is what happens when a current condition changes the way we remember the past. After a child has been diagnosed, parents might "remember" exaggerated milk consumption, especially if they've heard that milk might be the culprit.

Second, parents were interviewed closer in time to their child's infancy, making it easier to remember accurately when the child stopped breast feeding and switched to cow's milk, and when he began eating other foods, like cereal, fruit, vegetables and meat.

The researchers evaluated 253 children between the ages of 9 months and 7 years who came from families where a close relative had diabetes. They found 18 children with beta cell autoimmunity. They continued to study those 18, along with 153 of the at-risk children who showed no signs of beta cell autoimmunity. What they found was that children from both groups were of similar age when they began eating cereal, fruit, vegetables and meat. Also, equal proportions from each group had been breast fed.

Surprisingly, in every age group and in every risk group, those without beta cell autoimmunity were more likely to have been exposed to cow's milk and to have breast fed for two months less than those with autoimmunity.

The researchers in this study concluded that denying cow's milk to children from families with diabetes is unlikely to be the key to preventing diabetes.

In general, breast feeding is considered ideal for most babies, but the time comes to wean and move the child on to other foods. Then cow's milk plays an important role in good nutrition. If milk is eliminated, special efforts are needed to be sure nutrition is adequate.

In addition, Drs. Desmond Schatz and Noel Maclaren point out in their JAMA editorial that while many countries show a relationship between drinking cow's milk and rates of diabetes, this is not true in Sardinia. There, diabetes rates are second only to Finland's. Yet Sardinians drink less than half as much milk. They further note that animal studies show no relationship between feeding skim milk and diabetes development.

A much clearer picture is needed before milk can be declared the culprit in diabetes. Further studies are being conducted in Canada and Scandinavia but will take years to complete. If your family has a strong history of diabetes and you're tempted to eliminate cow's milk from your baby's diet, be sure to work closely with your doctor and dietitian to assure optimal nutrition for your growing child.

Colleen Pierre, a registered dietitian, is the nutrition consultant to the Union Memorial Sports Medicine Center and Vanderhorst & Associates in Baltimore.

Pub Date: 9/10/96

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