Will a high-carbohydrate, low-fat diet lower plasma lipids and lipoproteins without producing hypertriglyceridemia?
A sudden increase in dietary carbohydrate invariably increases the plasma levels of very low density lipoprotein (VLDL) and triglyceride. The present studies were designed to test the hypothesis that dietary carbohydrate-induced hypertriglyceridemia need not occur. In the first study we fed gradually increasing amounts of carbohydrate and gradually decreasing amounts of fat to eight subjects. The usual American diet (40% fat, 45% carbohydrate, and 15% protein) was followed in sequence by four diets in a phased regimen, the carbohydrate increasing by 5% of total calories and the fat content decreasing by 5% for each dietary period. In the last dietary period (phase 4), 20% of the energy was in the form of fat and 65% in the form of carbohydrates; the cholesterol content was 100 mg/day. Throughout the study, plasma triglyceride and VLDL triglyceride levels did not change significantly. The plasma total and low density lipoprotein (LDL) cholesterol levels were greatly reduced, by 15% and 22%, respectively (p = 0.004). Plasma high density lipoprotein (HDL) cholesterol levels decreased concomitantly. In the second study, after a washout period six of the subjects were initially fed the phase 4 high-carbohydrate diet for a 10-day period. The plasma triglyceride concentration increased over baseline levels by 47%, and VLDL triglyceride levels increased by 73%. We conclude that although a sudden increase in dietary carbohydrate increases the plasma triglyceride level, patients gradually introduced to a high-carbohydrate, low-fat diet may achieve a significant reduction of plasma total and LDL cholesterol without developing carbohydrate-induced hypertriglyceridemia.
Ullmann
D
D
Department of Medicine, Oregon Health Sciences University, Portland 97201-3098.
Connor
W E
WE
Hatcher
L F
LF
Connor
S L
SL
Flavell
D P
DP
D000328:Adult; D001059:Apoproteins / Q000097:blood; D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood*; D015243:Cholesterol, VLDL / Q000097:blood*; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D015228:Hypertriglyceridemia / Q000097:blood* / Q000209:etiology; D008055:Lipids / Q000097:blood*; D008297:Male; D008875:Middle Aged; D014280:Triglycerides / Q000097:blood
D001059:Apoproteins; D008078:Cholesterol, LDL; D015243:Cholesterol, VLDL; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D008055:Lipids; D014280:Triglycerides; D002784:Cholesterol