Cutting Fat in Kid's Diets Will Not Impair Their Development By Mike Field Children with abnormally high cholesterol levels can safely follow a low-fat diet without suffering a decline in growth, anemia or learning problems, researchers at the School of Medicine have found. Peter Kwiterovich, professor of medicine and pediatrics, presented the findings of the three-year, multicenter study at the American Heart Association's 67th Scientific Sessions held earlier this month in Dallas. Though significant, they represent only a small part of the ongoing research efforts being conducted at the Hopkins Lipid Research Clinic and the Lipid Research-Atherosclerosis Unit, which Dr. Kwiterovich has headed since its inception in 1971. "Coronary artery disease is still the No. 1 cause of morbidity and mortality in this country," Dr. Kwiterovich said. "Heart disease, hypertension and stroke cost the economy approximately $128 billion annually, and result in more than 1 million heart catheterizations and surgical procedures each year. And yet, out of all the people who develop early heart disease only in one of 20 cases is the basis of the disease known." Dr. Kwiterovich has spent his career trying to find out what makes the heart stop ticking, especially when it stops prematurely. Early heart disease, defined as heart problems occurring at age 55 or less in men, age 65 or less in women, is slowly beginning to be understood. Dr. Kwiterovich has played a significant role in developing the new understanding. In 1980, he co-discovered hyperapoB, the most commonly recognized lipoprotein disorder involved in the cause of premature coronary heart disease. More recently, he and colleagues have discovered three new proteins in human blood that permit the detection of a novel cell abnormality in patients with hyperapoB and coronary heart disease. "The Lipid Research-Atherosclerosis Unit is a multidisciplinary effort that conducts research ranging from clinical trials, such as the Dietary Intervention Study in Children that examined the effects of low-fat diets in children, to fundamental molecular and genetic research into the nature of heart disease," Dr. Kwiterovich said. "In the middle, we work with families with a history of heart disease performing DNA and blood tests to try to identify and predict risk factors." The Dietary Intervention Study in Children screened more than 47,000 eligible boys and girls aged 8 to 10 in Baltimore, Chicago, Iowa, New Jersey, New Orleans and Portland to select 663 participants with abnormally high levels of cholesterol. Half of the children and their parents, assigned to the intervention group, were subject to six months of intensive, behaviorally oriented classes in shopping, food preparation and eating a low-fat diet. The other half was put in the usual care group where they received a general diet information packet and no additional counseling. The intervention group subjects significantly reduced their cholesterol level over the usual care group during the study. Yet each group showed an average height increase of 8 inches during the length of the study, nor was there a difference in the blood ferritin levels between the groups, indicating the low-fat diet was not deficient in iron. No significant differences were found for any secondary outcome measures such as serum zinc, folate, retinol or albumin, nor did the reduced-fat diet affect the onset of sexual maturation, measures of cognitive development or child behavior. "We concluded the low-fat diet was effective and safe in rapidly growing boys and girls with elevated low-density lipoprotein cholesterol levels," Dr. Kwiterovich said. "These results are important for healthy children, aged 2 and older, who suffer from excessively high levels of LDL cholesterol because they indicate safe, effective treatment is available. We recommend that if children have a family history of premature heart disease--if a parent, grandparent, aunt or uncle was affected--then the child should be brought in for a complete blood lipid profile some time after the age of 2." Though intensive intervention appeared successful at reducing cholesterol levels over a three-year period, it is unclear how significant the benefits will be or how long the changed behavior will last. "The hard part of the low-fat diet is fast food," Dr. Kwiterovich said. Whether the study group can survive the teen-age years without large helpings of hamburgers, fries and pizza remains to be seen. The second phase of the study, currently in progress, will follow the participants until they reach the age of 18. "Knowledge is not always translated into behavioral change," Dr. Kwiterovich said. "Subjects in the intervention group participated in 12 weeks of classes in a social setting that focused on substitution rather than elimination. Ground round steak is only 8 percent fat; you can mix that with ground turkey, top it with low fat cheese and you've got a great cheeseburger." It is not known, however, if high-chol-esterol, high risk teen-agers will eat low-fat cheeseburgers eight or even 10 years after intervention. Meanwhile, Dr. Kwiterovich directs research aimed at discovering what causes heart disease to develop. Researchers in his lab recently received a grant from the National Institutes of Health to re-examine high-risk families ascertained from 1985 to 1988 in the Hopkins Coronary Artery Disease Study. They will examine the genetic basis of hyperaboB and premature heart disease. "We believe a receptor gene defect is present in a number of fanilies with early heart disease, and we are using cell biology and molecular biology to take an in-depth look," he said. "One out of three subjects with early heart disease has hyperaboB, which characterizes the presence of small, dense LDLs that contribute to heart disease." If the relationship between cellular defect and heart disease proves reliable, it could be a major step forward in identifying potential heart disease victims far enough in advance to introduce prophylactic dietary or drug therapies, he said. "We feel as though we're on the verge of a breakthrough," Dr. Kwiterovich said. "Our goal is to discover an important cause of heart disease, and thus create better tools for the diagnosis and treatment of the country's No. 1 killer." Individuals with a family history of premature heart disease can arrange a complete blood profile to reveal risk factors through the Lipid Clinic. Call 955-3197 for details.
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