Submitted to: Journal Of The American Dietetic Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/2002
Publication Date: 4/1/2002
Citation: Nicklas, T., Dwyer, J., Feldman, H.A., Luepker, R.V., Kelder, S.H., Nader, P.R. 2002. Serum cholesterol levels in children are associated with dietary fat and fatty acid intake. Journal Of The American Dietetic Association. 102(4):511-517. Interpretive Summary: Recent studies in adults suggest that individual dietary fats differ markedly in their effects on blood lipid levels. However, these associations have rarely been studied in children. The goal of this study was to examine the associations between individual dietary fats, protein, and carbohydrates and blood lipid levels in 1,182 children who participated in the child and Adolescent Trial for Cardiovascular Health (CATCH). The sample of children was equally distributed across four sites (LA, TX, MN, CA), in 96 elementary schools (56 intervention; 40 control) (48% males, 71% whites, 15% Hispanic, 10% blacks, 2% Asian, and 2% other or unspecified). Food record assisted 24-hour dietary recalls and blood lipid measurements were collected on each child when they were in the 3rd grade and again when they were in the 5th grade. Increased intake of dietary fat was significantly associated (p<0.01) with increased blood total cholesterol; whereas increased intake of carbohydrates was associated with decreased blood total cholesterol (p<0.01) and high density lipoprotein cholesterol (p<0.005) levels. Increased intake of total protein was significantly associated (p<0.05) with increased high-density lipoprotein cholesterol levels. Intakes of saturated (p<0.04) and unsaturated (p<0.03) fats and myristic fatty acid (p<0.01) all increased blood total cholesterol. In conclusion, the effect of dietary fats on blood lipid levels in children is similar to that observed in adults.
Technical Abstract: Recent studies in adults suggest that individual dietary fatty acids differ markedly in their effects on serum lipids and lipoprotein levels. However, these associations have rarely been studied in children. To assess the associations in children between specific fatty acids and nonfasting serum lipids and cholesterol after controlling for total energy intake and total fat using regression procedures. The sample consisted of 1,182 children who participated in the Child and Adolescent Trial for Cardiovascular Health (CATCH). The sample was equally distributed across four sites (LA, TX, MN, CA), (48% males, 71% Euro-American, 15% Hispanic-American, 10% African-American, 2% Asian,and 2% from other or unspecified racial/ethnic hertitage). In this randomized multicenter trial with 56 intervention and 40 control elementary schools, food record-assisted 24-h dietary recalls and serum lipid measurements were collected for each child at baseline (3rd grade) and at the 5th grade follow-up. Repeated-measures analysis of variance was used to evaluate the association between nutrient composition of the diet and serum lipids. Independent dietary variables included amount and type of fat, individual fatty acids, protein, carbohydrate and fiber. The dependent variables were the absolute values of serum total cholesterol [TC] and high density lipoprotein cholesterol [HDL-C] both at baseline (3rd grade) and at follow-up (5th grade). Increased total fat (b=0.053; p<0.03) were associated with increased TC in the model when energy was held constant, whereas increased carbohydrate was associated with decreased TC (b=-0.021; p<0.02) and HDL-C (b=-0.010; p<0.005) levels. Increased total protein (b=0.017; p<0.05) was associated with increased HDL-C when energy was held constant. Saturated (b=0.004; p<0.04), and unsaturated (b=0.004; p<0.03) fat and myristic fatty acid (b=0.021; p<0.01) all increased TC in the model when total fat and total energy were held constant. We conclude that using a modeling approach, the effect of diet on serum lipids in children is similar to that observed in adults. Total fat and saturated fat were positively associated with TC and HDL-C levels, saturated fat positively associated with TC, and carbohydrate inversely associated with both TC and HDL-C. In the statistical model, substitution of unsaturated fatty acids, monounsaturated fatty acids, or oleic acid for saturated fat, while holding total fat and energy constant, had slight effects on TC lowering. In contrast, substitution of total fat for carbohydrate in the model increased TC and, thus, did not appear to be associated with an apparent health advantage except for HDL-C elevating effects. However, consumption of individual fats tends to be highly correlated, and we were unable to determine if these biological effects were operating independently.